PROCESS FOR PREPARING HEART-SHELL HYBRID MATERIALS

专利摘要:
The invention relates to a process for preparing a core-shell hybrid material consisting of an activated carbon core surrounded by a mesoporous sol-gel silica shell, said process comprising the formation of a sol-gel silica shell mesoporous around activated carbon particles.
公开号:FR3061708A1
申请号:FR1750145
申请日:2017-01-06
公开日:2018-07-13
发明作者:Thu-Hoa Tran-Thi；Christophe Theron；William BAMOGO
申请人:Centre National de la Recherche Scientifique CNRS；Commissariat a lEnergie Atomique CEA；Commissariat a lEnergie Atomique et aux Energies Alternatives CEA；
IPC主号:

专利说明:

@ Holder (s): ATOMIC ENERGY AND ALTERNATIVE ENERGY COMMISSIONER, NATIONAL CENTER FOR SCIENTIFIC RESEARCH - CNRS - Public establishment.
® Agent (s): CABINET PLASSERAUD.
® PROCESS FOR THE PREPARATION OF HYBRID HEART-SHELL MATERIALS. @) The invention relates to a process for preparing a hybrid core-shell material consisting of an activated carbon core surrounded by a mesoporous sol-gel silica shell, said process comprising the formation of a sol silica shell - mesoporous gel around activated carbon particles.
FR 3,061,708 - A1
The invention relates to the preparation of hybrid core-shell materials consisting of an activated carbon core surrounded by a layer of a nanoporous sol-gel material based on silica as well as the core-shell hybrid materials as such. These materials find application in the field of filtration, in particular water and air.
The available fresh water represents only 0.26% of the world's water and its quantity remains practically unchanging. The population, meanwhile, continues to grow and the demand for water is increasing. According to the report of the World Health Organization (WHO), 748 million people still do not have access to drinking water in 2014 and 1.8 billion people would use unsafe water, contaminated by faeces [1]. Furthermore, according to a projection by the Bureau of Geological and Mining Research [2], in 2025, 63% of the world population should suffer from a water shortage. It will become necessary to desalinate the seawater and to reprocess the wastewater to make the water potable. These treatments already exist but are too expensive for developing countries.
In developed countries, conventional surface water treatment for the supply of drinking water involves several stages including coagulation, sedimentation, filtration and disinfection. Coagulation by adding coagulants makes it possible to aggregate the dissolved or suspended particles in the water which will precipitate and settle in the settling tank. Filtration involves several stages including a first filtration by sand which removes the last particles in suspension. This is followed by ozone and activated carbon treatments to destroy and trap total organic compounds (TOC). At this stage, compounds smaller than 100 nm in size may still be present in water. To remove viruses and organic compounds, membrane filtration, such as ultrafiltration or nanofiltration, is used. Both ultrafiltration and nanofiltration pass micro-pollutants such as pesticides, drug residues and other organic compounds, of which there are approximately 5,000 different products.
Certain micro-pollutants may react with the chlorine used for disinfecting water to form disinfection by-products called toxic or carcinogenic "emerging pollutants" such as chloramines, nitrosamines and trihaloalkanes.
Even if the standards required in developed countries for drinking water are drastic in terms of concentration of total organic compounds ([TOC] <2 ppm) [3], daily consumption of water contaminated with traces or ultra- traces of drug residues whose antibiotics, pesticides or sex hormones could induce long term harmful effects on health.
It is therefore necessary to further reduce the content of total organic compounds in drinking water. Reverse osmosis is the most effective method for removing small organic molecules but its energy cost is also the highest because of the high pressures to be applied to pass water through a semi-permeable membrane with very small pores . In recent years, work has emerged on direct osmosis with the use of composite membranes for the removal of organic compounds, but osmosis is mainly used for desalination of seawater.
Nowadays, activated carbon is widely used for cleaning up water. However, only it remains ineffective in the case of small polar molecules (formaldehyde, acetaldehyde, methyl and ethyl ketones), and new organic pollutants such as pesticides (glyphosate), drug residues (of human or animal origin) or still micropollutants (chloroform, methylene chloride, acetonitrile, dimethylformamide, isopropyl alcohol etc ...) coming from the industrial field [4].
To replace activated carbon, various nanostructured materials have been proposed in the literature. These nanostructured materials can be zeolites [5], mesoporous molecular sieves [6], silica nanoparticles [7], or microporous titanosilicates [8]. In recent years, activated carbon has also been combined with sol-gel materials. It is used in the majority of cases in order to increase the photocatalysis yield of TiO ₂ . We thus find:
Activated carbon grains were coated with TiO ₂ by the sol-gel route. The targeted applications are the decontamination of water, in particular waste water containing dyes [9], [10], the degradation of Rhodamine B [11], as well as the decomposition of NH ₃ or formaldehyde [12] , [13].
TiO _2> powder synthesized by sol-gel, deposited on activated carbon by impregnation [14]. The objective is to decontaminate liquids containing in particular dibenzothiophene.
TiO ₂ obtained by the sol-gel method associated with carbon nanotubes by grafting or coating [15]. The aim is also to improve the photocatalysis yield of TiO ₂ , with applications in the environmental sector.
Work associating activated carbon with a sol-gel based on silicon is rarer. Activated carbon can simply play the role of support before being eliminated by carbonization, and is not present in the final product obtained [16]. A hybrid core-shell material with an activated carbon core surrounded by non-functionalized silica prepared by the sol-gel route in ethanol has also been described by Guo et al. [16]. These materials are intended for use as photonic crystals. In view of the FESEM images disclosed in the article, it appears that the materials are aggregated into very large monoliths.
The depollution of air and in particular volatile organic compounds via air purifiers or extractor hoods is essentially based on the use of activated carbon filters. The latter indeed has a significant adsorption capacity and a low cost. However, activated carbon very poorly traps small polar molecules present in indoor air such as formaldehyde, acetaldehyde, methyl and ethyl ketones, acetic acid or even acrylamide resulting from the decomposition of the oil. overheated (fried food and others). In order to compensate for this ineffective trapping of small and polar VOCs by activated carbon, the latter is often impregnated with reagents capable of reacting with the target pollutants. However, a disadvantage of impregnated materials is the release into the air of the impregnating reagents or of the products resulting from their reaction.
In view of the above, there is always a need for new filtering materials, in particular for the filtration of water and gases, such as air, combining high filtration capacity of different types of molecules, polar and nonpolar. material with a simple and effective preparation process.
An object of the invention is therefore to propose a simple and efficient method of manufacturing a filter material making it possible to achieve these performances.
It is to the credit of the inventors to have discovered, very unexpectedly and after much research, that it was possible to achieve this goal with a particular process for the preparation of a filtering material combining activated carbon and a sol material - mesoporous gel in the form of nanoparticles, thus forming a material with an activated carbon core and a shell of sol-gel nanoparticles.
A sol-gel material is a material obtained by a sol-gel process consisting in using metal alkoxides of formula M (0R) _x R ' _{nx as} M precursors or M is a metal, in particular silicon, R an alkyl group and R' a group carrying one or more functions with n = 4 and x which can vary between 2 and 4. In the presence of water, the alkoxy groups (OR) are hydrolyzed into silanol groups (Si-OH). These condense to form siloxane bonds (Si-O-Si-). When the silicate precursors in low concentration in an organic solvent are added dropwise to a basic aqueous solution, particles of size generally less than 1 μm are formed, which remain in suspension without precipitating. Depending on the synthesis conditions, it is possible to obtain monodisperse or polydisperse nanoparticles, of spherical shape, and the diameters of which can vary between a few nanometers to 2 μm. The porosity of the silica nanoparticles (microporisity or mesoporosity) can be varied by adding a surfactant.
A first subject of the invention therefore relates to a process for the preparation of a hybrid core-shell material consisting of an activated carbon core surrounded by a shell of a mesoporous solgel material based on silica, said process comprising the formation of a mesoporous sol-gel silica shell around activated carbon particles and the recovery of the hybrid core-shell material thus obtained.
The mesoporous sol-gel silica shell is formed from at least one organosilicate precursor. It is thus possible to use a single organosilicon precursor or a mixture of organosilicon precursors. The at least one organosilicate precursor is advantageously chosen from tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), phenyltrimethoxysilane (PhTMOS), phenyltriethoxysilane (PhTEOS), (2-phenylethyl) triethoxysilane, 3-aminopropyl , (3-glycidyloxypropyl) trimethoxysilane (GPTMOS), (3glycidyloxypropyl) triethoxysilane (GPTES), N- (2-Aminoethyl) -3- (trimethoxysilyl) propylamine (NH ₂ -TMOS), N- (Trimethoxysilylpropyl) ethylateiaminetriac , acetoxyethyltrimethoxysilane (AETMS), ureidopropyltriethoxysilane (UPTS), 3- (4-semicarbazidyl) propyltriethoxysilane (SCPTS) and their mixtures, preferably among tetramethoxysilane (TMOS), tetraethoxysilane (TEOSeth) phenyl ), phenyltriethoxysilane (PhTEOS), (3glycidyloxypropyl) triethoxysilane (GPTES), N- (2-Aminoethyl) -3- (trimethoxysilyl) propylamine (NH ₂ -TMOS), 3-aminopropyltrethoxysilane (APTES), N- (Trimethoxysilylpropyl) ethylenediaminetriacet ate, acetoxyethyltrimethoxysilane (AETMS), 3- (4semicarbazidyl) propyltriethoxysilane (SCPTS) and their mixtures.
In one embodiment, the organosilicate precursor is tetraethoxysilane or tetramethoxysilane, preferably tetraethoxysilane. In another embodiment, the organosilicon precursor is a mixture of tetramethoxysilane or tetramethoxysilane and of a functionalized organosilicon precursor. Advantageously, these are amine, amide, urea, acid or aryl functions. The functionalized organosilicate precursor can in particular be chosen from phenyltrimethoxysilane (PhTMOS), phenyltriethoxysilane (PhTEOS), (2phenylethyl) triethoxysilane, 3-aminopropyltriethoxysilane (APTES), (3glycidyloxypropyl) trimethoxysyl) propyl) triethoxysilane (GPTES), N- (2-Aminoethyl) -3- (trimethoxysilyl) propylamine (NH ₂ -TMOS), N (Trimethoxysilylpropyl) ethylenediaminetriacetate, 1 'acetoxyethyltrimethoxysilane (AETMS), uréidopropyltriethoxysilane (UP) - (4-semicarbazidyl) propyltriethoxysilane (SCPTS) and their mixtures, preferably among phenyltrimethoxysilane (PhTMOS), phenyltriethoxysilane (PhTEOS), (3-glycidyloxypropyl) triethoxysilane (GPTES), N- (2-Aminoethyl) (trimethoxysilyl) propylamine (NH ₂ -TMOS), 3-aminopropyltrethoxysilane (APTES), N3061708 (Trimethoxysilylpropyl) ethylenediaminetriacetate, acetoxyethyltrimethoxysilane (AETMS), 3- (4semicarbazidyl) propylanerietriox mixtures.
Mixtures of preferred organosilicate precursors include mixtures of tetraethoxysilane (TEOS) with N- (2-Aminoethyl) -3- (trimethoxysilyl) propylamine (NH ₂ -TM0S), with N- (Trimethoxysilylpropyl) ethylenediammetriacetate, with phenyltriemthoxysane (PhTMOS) and with 3- (4-semicarbazidyl) propyltriethoxysilane (SCPTS) as well as mixtures of tetramethoxysilane (TMOS) with 3-aminopropyltriethoxysilane (APTES), with phenyltriemethoxysilane (PhTMOS), with phenyltriethox with acetoxyethyltrimethoxysilane (AETMS), with (3-glycidyloxypropyl) triethoxysilane (GPTES) and with 3- (4-semicarbazidyl) propyltriethoxysilane (SCPTS).
When using a mixture of tetramethoxysilane and one or more other organosilicate precursors, the molar proportions of tetramethoxysilane (TMOS) / other (s) organosilicate precursor (s) can be varied between 100/0 and 50/50, preferably between 100/0 and 75/25, more preferably between 97/3 and 75/25 or between 98/2 and 89/11.
The activated carbon used for the present invention can be of vegetable or animal origin. Those skilled in the art will choose it according to the desired properties, in particular filtration. Thus, it is possible to use different forms of activated carbon, such as, for example, balls, powder, granules, fibers or sticks. Preferably, use will be made of an activated carbon with a large specific adsorption surface, in particular from 800 to 1500 m ² / g. The activated carbon can be mixed at different concentrations with the coating composition (sol-gel composition) to modulate the quantity of core / shell.
In a first embodiment, the method of the invention is characterized in that the formation of a mesoporous sol-gel silica shell around the activated carbon particles comprises:
a) the formation of a shell of sol-gel nanoparticles around particles of activated carbon in basic aqueous solution from at least one organosilicate precursor, the aqueous solution containing ammonia (NH ₄ OH) and a surfactant,
b) recovery of the activated carbon surrounded by the shell of sol-gel material prepared in step
at),
c) the elimination of any residual surfactant from the activated carbon surrounded by the shell of sol-gel material to release the pores of the sol-gel material formed in step a), and characterized in that in step a), a basic aqueous solution containing ammonia, the surfactant and the activated carbon is first supplied, then at least one organosilicate precursor is added, this precursor being dissolved in an organic solvent.
Thus, according to this embodiment, the process for preparing a hybrid core-shell material consisting of an activated carbon core surrounded by a mesoporous sol-gel silica shell comprises the following steps:
a) the formation of a shell of sol-gel nanoparticles around particles of activated carbon in basic aqueous solution from at least one organosilicate precursor, the aqueous solution containing ammonia (NH ₄ 0H) and a surfactant,
b) recovery of the activated carbon surrounded by the sol-gel silica shell prepared in step a),
c) the removal of any residual surfactant from the activated carbon surrounded by the shell of sol-gel material to release the pores of the sol-gel material formed in step a),
d) recovery of the hybrid core-shell material consisting of an activated carbon core surrounded by a mesoporous sol-gel silica shell obtained in step c), characterized in that in step a), first a basic aqueous solution containing ammonia, the surfactant and the activated carbon, then at least one organosilicate precursor is added, this precursor being dissolved in an organic solvent.
Surprisingly, this embodiment gives rise to discrete core-shell particles, the silica nanoparticles having weak agglomeration with one another. In view of the literature (see for example [19]), those skilled in the art have until now believed that it was necessary to carry out the synthesis of sol-gel nanoparticles in an organic solvent such as ethanol in order to on the one hand to form small monodisperse nanoparticles and on the other hand to avoid agglomeration of the nanoparticles between them. In the experiments of Rao et al. [18] for example, the quantities of ethanol and water vary between 1 to 8 mol / L and 3 to 14 mol / L, respectively and according to the concentration of the precursor in solution in ethanol, the authors obtain diameters of silica nanoparticles varying between 30 and 460 nm.
However, in this embodiment, the synthesis is carried out in aqueous solution and the contribution of the organic solvent for the solubilization of the organosilicate precursors is very low relative to the volume of the final sol. Advantageously, the amount of organic solvent is from 1 to 5% by volume, preferably from 1.5 to 4% by volume and more preferably still from 1.8 to 3% by volume relative to the final sol (ie that is to say the whole aqueous solution containing ammonia, the surfactant and the activated carbon plus the organosilicate precursor solubilized in the organic solvent). Advantageously, the basic aqueous solution supplied in step a) is free of organic solvent and the organic solvent is only provided with the organosilicate precursors. Without wishing to be bound by any theory, the inventors believe that it is the sequence of addition of the various reagents which makes it possible to avoid agglomeration of the nanoparticles despite the use of an aqueous solvent. It seems essential to add the organosilicate precursor last.
The organic solvent used to dissolve the organosilicate precursor (s) will be chosen by a person skilled in the art according to the organosilicate precursor or the mixture of organosilicate precursors used, in particular from polar, protic or aprotic organic solvents. This organic solvent can for example be chosen from linear C1 to C4 aliphatic alcohols, in particular methanol, ethanol and propan-1-ol. Preferably, the organic solvent is ethanol.
Organosilicon precursors and activated carbon which can be used in this embodiment are those detailed above. Preferably, the at least one organosilicate precursor is chosen from tetraethoxysilane (TEOS), phenyltrimethoxysilane (PhTMOS), phenyltriethoxysilane (PhTEOS), (2-phenylethyl) triethoxysilane, 3-aminopropyltriethoxysilane (APTES) -glycidyloxypropyl) trimethoxysilane (GPTMOS), (3glycidyloxypropyl) triethoxysilane (GPTES), N- (2-Aminoethyl) -3- (trimethoxysilyl) propylamine (NH ₂ -TMOS), N- (Trimethoxysilylpropyl) ethylenediaminetriacetate (AETMS), ureidopropyltriethoxysilane (UPTS), 3- (4-semicarbazidyl) propyltriethoxysilane (SCPTS) and their mixtures, preferably among tetraethoxysilane (TEOS), N- (2-Aminoethyl) -3 (trimethoxysilyl) propylamine (NH ₂ -TMOS), N- (Trimethoxysilylpropyl) ethylenediaminetriacetate, phenyltriemthoxysilane (PhTMOS), 3- (4-semicarbazidyl) propyltriethoxysilane (SCPTS) and their mixtures. When using a mixture of tetraethoxysilane and a functionalized organosilicon precursor, the following mixtures are preferred: tetraethoxysilane with N- (2-Aminoethyl) -3 (trimethoxysilyl) propylamine (NH ₂ -TMOS), with N (Trimethoxysilylpropyl) ethylenediaminetriacetate, with phenyltriemthoxysilane (PhTMOS) and with 3- (4-semicarbazidyl) propyltriethoxysilane (SCPTS). The activated carbon is preferably in powder form, in particular of micrometric size.
When using a mixture of tetramethoxysilane or tetraethoxysilane, preferably tetraethoxysilane, and one or more functionalized organosilicate precursors, the molar proportions of tetramethoxysilane (TMOS) or tetraethoxysilane (TEOS) / other (s) precursor (s) ) organosilicon (s) can be varied between 100/0 and 50/50, preferably between 100/0 and 75/25, more preferably between 97/3 and 75/25 or between 98/2 and 89/11.
The basic aqueous solution used in step a) is preferably an aqueous ammonia solution at a concentration of 0.8 to 3.2 mol.L ', preferably from 2.0 to 2.3 mol. L
The basic aqueous solution used in step a) may contain a small amount of organic solvent, in particular polar, protic or aprotic solvent. This organic solvent can for example be chosen from linear C1 to C4 aliphatic alcohols, in particular methanol, ethanol and propanol. Preferably, the organic solvent is ethanol. Preferably, the content of organic solvent does not exceed 5% by volume. More preferably, the basic aqueous solution is free of organic solvent.
The role of the surfactant used during step a) of the first embodiment is on the one hand to promote the interaction between the surface of the activated carbon and the siliceous precursors and on the other hand to structure the network of the silica to make it mesoporous. The surfactant used in step a) is preferably an ionic surfactant, more preferably a quaternary ammonium compound. This quaternary ammonium compound is advantageously a cetyltrimethylammonium halide, preferably cetyltrimethylammonium bromide or cetyltrimethylammonium chloride, more preferably cetyltrimethylammonium bromide.
The recovery of the core-shell material of activated carbon surrounded by the shell of sol-gel material in step b) of the first embodiment can for example be carried out by separation, by any known means and in particular by centrifugation or filtration, of the mixture obtained during step a). Preferably, the core-shell material is recovered by centrifugation in the first method.
The elimination of any surfactant residues present in the core-shell material in step c) can be carried out by any known means and in particular by washing, for example with hydrochloric acid and ethanol, preferably by succession of washes with hydrochloric acid and ethanol.
The recovery of the core-shell material of activated carbon surrounded by the shell of sol-gel material in step b) can for example be carried out by separation, by any known means and in particular by centrifugation or filtration, of the mixture obtained during the 'step a). Preferably, the core-shell material is recovered by centrifugation. Removal of the surfactant frees the pores from the material obtained in step b). After this elimination step, the hybrid core-shell material consisting of an activated carbon core surrounded by a shell of silica-based mesoporous sol-gel nanoparticles is thus obtained.
This hybrid core-shell material is recovered in step d). This recovery can for example be carried out by separation, by any known means and in particular by centrifugation or filtration, of the mixture obtained during step a). Preferably, the hybrid core-shell material is recovered by centrifugation.
In a second embodiment, the method of the invention is characterized in that step a) of forming the mesoporous sol-gel silica shell comprises the preparation of a soil for mixing at least one organosilicate precursor in an aqueous solution containing an organic solvent followed by coating the activated carbon with this sol. A thin film of mesoporous sol-gel silica, preferably functionalized, is thus formed around the activated carbon particles. Preferably, the soil is free of surfactant.
The organic solvent is preferably a polar, protic or aprotic organic solvent. It can for example be chosen from linear aliphatic alcohols, C1 to C4, in particular methanol, ethanol and propan-l-ol. Preferably, the organic solvent is methanol. The volume proportion of the organic solvent relative to the volume of the soil can vary between 30 to 50%. The volume proportion of water to the volume of the soil can vary between 15 and 30%.
The organosilicon precursors and the activated carbon which can be used in this embodiment are those detailed above with respect to the process according to the invention in general. Preferably, the at least one organosilicate precursor is chosen from tetramethoxysilane (TMOS), phenyltrimethoxysilane (PhTMOS), phenyltriethoxysilane (PhTEOS), (2phenylethyl) triethoxysilane, 3-aminopropyltriethoxysilane (APTES)) (GPTMOS), (3-glycidyloxypropyl) triethoxysilane (GPTES), N- (2-Aminoethyl) -3- (trimethoxysilyl) propylamine (NH ₂ -TMOS), N (Trimethoxysilylpropyl) ethylenediaminetriacetate, 1 'acetoxyethyltrimethoxysilane (AET) , ureidopropyltriethoxysilane (UPTS), 3- (4-semicarbazidyl) propyltriethoxysilane (SCPTS) and their mixtures, more preferentially among tetramethoxysilane (TMOS), 3 aminopropyltriethoxysilane (APTES), phenyltriemethtosilane phenophtane) , acetoxyethyltrimethoxysilane (AETMS), (3glycidyloxypropyl) triethoxysilane (GPTES) and 3- (4-semicarbazidyl) propyltriethoxysilane (SCPTS). When using a mixture of tetramethoxysilane and a functionalized organosilicate precursor, the following mixtures are preferred: tetramethoxysilane (TMOS) with 3 aminopropyltriethoxysilane (APTES), with phenyltriemethoxysilane (PhTMOS), with phenyltriethoxysilane, PhTE) acetoxyethyltrimethoxysilane (AETMS), with (3glycidyloxypropyl) triethoxysilane (GPTES) and with 3- (4-semicarbazidyl) propyltriethoxysilane (SCPTS).
When using a mixture of tetramethoxysilane and one or more functionalized organosilicate precursors, the molar proportions of tetramethoxysilane (TMOS) / other organosilicate precursor (s) can be varied between 100/0 and 50/50, preferably between 100/0 and
75/25, more preferably between 97/3 and 75/25.
According to a first variant of this second embodiment, the activated carbon is in the form of particles, in particular of granules or sticks, of millimeter size and the coating is carried out by soaking them in the soil then removing the soil or by pouring the soil over the particles through a sieve. The core-shell particles thus obtained are advantageously dried, for example in an oven, to remove the residual solvents. Preferably, sticks of activated carbon will be used, in particular of millimeter size. Particular preference will be given to the casting method to form a thin film of functionalized sol-gel material around the activated carbon core. This rapid process is easily transposable to an industrial scale and is well suited to activated carbon in granules or sticks.
According to a second variant of this second embodiment, the activated carbon is in the form of powder and the coating is carried out by adding activated carbon powder to the soil, then the mixture obtained is poured into molds. The molds thus filled are advantageously dried under an inert gas flow to remove the residual solvents before demoulding the blocks of core-shell material. This process can easily be transposed to an industrial scale.
In the two embodiments described above, the silica shell, preferably functionalized, surrounding the activated carbon core, in the form of nanoparticles or a thin film, must have a small thickness and a mesoporosity to allow the pollutants to diffuse quickly in the porous network and reach the silica-activated carbon interface. It is at this interface of the hybrid compound that a "mixed" environment promotes the trapping of polar molecules that hardly or not at all trap activated carbon alone or silica alone.
Another object of the invention is a hybrid core-shell material obtained by the coating process according to the invention described above. It is therefore a hybrid core-shell material consisting of an activated carbon core surrounded by a mesoporous sol-gel silica shell.
All the details and embodiments set out above with respect to the nature of the sol-gel material and of the activated carbon are also valid for the hybrid core-shell material according to the invention. The hybrid core-shell material according to the invention is in particular characterized in that it contains an activated carbon core, in particular of micrometric size, preferably with a large specific adsorption surface, in particular from 800 to 1500 m ² / g, the surface of which is covered with a shell formed of mesoporous sol-gel silica. This shell is thin. Its mesoporosity allows pollutants to diffuse rapidly in the porous network and reach the active silica interface. It is at this interface of the hybrid compound that a “mixed” environment favors the trapping of polar molecules that hardly or not at all trap the activated carbon alone or the silica alone. The ratio (Mass of silica / Mass of activated carbon) determined by Thermal Analysis
Differential (ATG) preferably varies between 0.05 and 6, preferably between 0.05 and 2 and more preferably between 0.05 and 0.2.
In a first embodiment, the shell of the hybrid core-shell material according to the invention consists of nanoparticles of mesoporous sol-gel silica. These nanoparticles are advantageously spherical in shape, in particular having a diameter of 20 to 400 nm and preferably between 50 and 100 nm. The size of the silica nanoparticles can be determined by transmission electron microscopy. The ratio (mass of silica / mass of activated carbon) determined by differential thermal analysis (ATG) preferably varies between 0.05 and 0.2. The hybrid core-shell material of this embodiment can be prepared according to the first embodiment of the method of the invention described above.
In a second embodiment, the shell of the hybrid core-shell material according to the invention consists of a thin film of mesoporous sol-gel silica. The hybrid shell core material of this embodiment can be prepared according to the second embodiment of the method of the invention described above. The ratio (mass of silica / mass of activated carbon) determined by differential thermal analysis (ATG) preferably varies between 0.05 and 0.2. However, in the case of hybrid materials synthesized by mixing activated carbon with a soil, this ratio is higher and varies between 4 and 6, but could be reduced to lower values for better efficiency.
The materials according to the invention find a particular application in the field of filtration, in particular air or water. The invention therefore also relates to a filtering system, for example of air or water, comprising the hybrid core-shell material according to the invention.
Nonlimiting examples of embodiment of the invention are described below.
FIGURES
Figure 1: Schematic representation of the synthesis of core / shell materials
Figure 2: (A) TEM image of the hybrid core-shell material of Example 1.
Figure 2: (B) TEM image of the hybrid core-shell material of Example 1, enlargement on the surface.
Figure 3: MET image of activated carbon W35. Magnification on the surface.
Figure 4: (A) TEM image of the hybrid core-shell material of Example 2. (B) TEM image of the hybrid core-shell material of Example 2. Magnification on the surface.
Figure 5: TEM images of hybrid core-shell materials from complement example 2 with different proportions of NH ₂ -TMOS: (A) 10 pL, (B) enlargement of the material prepared with 10 pL, (C) 20 pL, (D) 50 pL, (E) 100 pL, (F) 200 pL.
Figure 6: TEM image of the hybrid core-shell material of example 3.
Figure 7: TEM image of the hybrid core-shell material of example 4.
Figure 8: TEM image of the hybrid core-shell material of example 5.
Figure 9: SEM image of a CA stick (Darco-KGB) coated with hybrid sol-gel from Example 6. A) view of the stick, B) Zoom on its surface, C) Magnification of the surface, D Estimation of the thickness of sol-gel.
Figure 10: Infrared spectrum of the hybrid material of Example 1 compared to activated carbon alone.
Figure 11: Infrared spectrum of the hybrid material of Example 2 compared to activated carbon alone.
Figure 12: Infrared spectrum of the hybrid material of Example 3 compared to activated carbon alone.
Figure 13: Infrared spectrum of the hybrid material of Example 4 compared to activated carbon alone.
Figure 14: Differential thermal analysis of the product of Example 6. The sample is heated from 40 ° to 1500 ° C at the speed of 50 ° C / min. The successive slope variations indicate the successive mass losses of the residual water, the aminopropyl chains of the functionalized material, activated carbon and lastly silica.
Figure 15: Adsorption of atrazine by activated carbon W35 alone, the silica nanoparticles alone and the activated carbon / silica nanoparticle mixture as a function of time.
Figure 16: Adsorption of atrazine by the materials of Examples 1 to 5 as a function of time.
Figure 17: Adsorption of atrazine by the materials of Examples 13, 14 and 17 as a function of time.
Figure 18: Absorption at 222 nm of the residual atrazine in the nm impregnation solution as a function of the duration of impregnation of the CA Norrit RBBA. Comparison with the material of Example 6.
Figure 19: Adsorption of acetone by activated carbon W35 alone, the silica nanoparticles alone and the activated carbon / silica nanoparticle mixture as a function of time.
Figure 20: Adsorption of acetone by the materials of Examples 1 to 5 as a function of time.
Figure 21: Adsorption of acetone by the materials of Examples 13, 14 and 17 as a function of time.
Figure 22: Adsorption of acetaldehyde by active carbon W35 alone, silica nanoparticles alone and the activated carbon / silica nanoparticle mixture as a function of time.
Figure 23: Adsorption of acetaldehyde by the materials of Examples 1 to 5 as a function of time.
Figure 24: Adsorption of acetaldehyde by the materials of Examples 13, 14 and 17 as a function of time.
Figure 25: Adsorption of methiocarb by active carbon W35 alone, the silica nanoparticles alone and the mixture of activated carbon / silica nanoparticles as a function of time.
Figure 26: Adsorption of methiocarb by the materials of examples 1 to 5 as a function of time.
Figure 27: Adsorption of methiocarb by the materials of Examples 13, 14 and 17 as a function of time.
Figure 28: Adsorption of atrazine by the hybrid material of Example 1 after passage through the filter system.
Figure 29: Adsorption of methiocarb by Darco-KGB activated carbon and the materials of Examples 8, 10 and 12 as a function of time.
Figure 30: Adsorption of methiocarb by activated carbon W35 and the materials of Examples 9, 11 and 13 as a function of time.
Figure 31: Diagram of the syringe filtration system.
Figure 32: Example of an air filter application. Adsorption of toluene by the silica nanoparticles alone as a function of time.
Figure 33: Example of an air filter application. Adsorption of toluene by activated carbon W35 as a function of time.
Figure 34: Example of an air filter application. Adsorption of toluene by Example 4 as a function of time.
Figure 35: Application example for air filter. Overlay of the graph of activated carbon W35 alone, of the silica nanoparticles alone and of example 4, as a function of time.
EXAMPLES
A. Synthesis of activated carbon coated with silica according to the first embodiment
Example 1: Synthesis of non-functionalized coated activated carbon.
Reagents: Activated Carbon W35 (SOFRALAB), Tetraethyl orthosilicate (TEOS, CAS: 78-10-4, Molar mass = 208.33 g / mol and density d = 0.933), Methanol (MeOH, CAS: 67-56-1, Molar mass = 32.04 g / mol and density d = 0.791), Cetyltrimethylammonium bromide (CTAB, CAS: 57-09-0, Molar mass = 364.45 g / mol), Ammonia (NH ₄ OH, CAS: 1336 -21-6, Molar mass = 35.05 g / mol and density d = 0.9).
Procedure: In a bottle are mixed 0.64 g of activated carbon W35, 0.29 g of CTAB and 150 ml of an aqueous solution of NH ₄ OH previously prepared at a concentration of 2.048M. The solution is left under magnetic stirring at room temperature for 1 h. 6.5 ml of ethanolic TEOS at a concentration of 1.55 mM are then added dropwise and the solution is left under stirring for another hour at room temperature. The stirring is then stopped and the solution is left to mature overnight at 50 ° C. The solution is then recovered by centrifugation (12,000 rpm for 12 min). The surfactant is removed by a succession of washing with hydrochloric acid and ethanol before being stored in the latter. Before use, the materials are recovered by centrifugation (12,000 rpm for 12 min) then dried in an oven at 60 ° C for 2 h.
Example 2 Synthesis of Activated Charcoals Coated with Silica Functionalized with Amine Groups
Reagents: Activated Carbon W35 (SOFRALAB), Tetraethyl orthosilicate (TEOS, CAS: 78-10-4, Molar mass = 208.33 g / mol and density d = 0.933), Methanol (MeOH, CAS: 67-56-1, Molar mass = 32.04 g / mol and density d = 0.791), Cetyltrimethylammonium bromide (CTAB, CAS: 57-09-0, Molar mass = 364.45 g / mol), Ammonia (NH ₄ OH, CAS: 1336 -21-6, Molar mass = 35.05 g / mol and density d = 0.9), N- (2-Aminoethyl) -3- (trimethoxysilyl) propylamine (NH ₂ TMOS, CAS: 1760-24-3, Molar mass = 222.36 g / mol and density d = 1.028).
Procedure: In a plastic bottle are mixed 0.64 g of activated carbon W35, 0.29 g of CTAB and 150 ml of an aqueous solution of NH ₄ OH previously prepared at a concentration of 2.048M. The solution is left under magnetic stirring at room temperature for 1 h. 20 μL of NH ₂ -TMOS are then added followed by 6.5 ml of ethanolic TEOS at a concentration of 1.55 mM and the solution is left under stirring for another hour at room temperature. The stirring is then stopped and the solution is left to mature overnight at 50 ° C. The solution is then recovered by centrifugation (12,000 rpm for 12 min). The surfactant is removed by a succession of washing with hydrochloric acid and ethanol before being stored in the latter. Before use, the materials are recovered by centrifugation (12,000 rpm for 12 min) then dried in an oven at 60 ° C for 2 h.
Complement Example 2: Variation in the quantity of Amine functions
According to the protocol of Example 2, the amount of N- (2-Aminoethyl) -3 (trimethoxysilyl) propylamine was used with various ratios according to Table 1.
Table 1: Ratio of NH2-TMOS to TEOS
V NH2-TMOS (pL) n NH2-TMOS (pmol) nTEOS / n NH2-TMOS 10 42.73 157 20 85.47 79 50 213.67 31 100 427.34 15 200 854.68 8
EXAMPLE 3 Synthesis of Active Charcoals Coated with Silica Functionalized with Acid Groups
Reagents: Activated Carbon W35 (SOFRALAB), Tetraethyl orthosilicate (TEOS, CAS: 78-10-4, Molar mass = 208.33 g / mol and density d = 0.933), Methanol (MeOH, CAS: 67-56-1, Molar mass = 32.04 g / mol and density d = 0.791), Cetyltrimethylammonium bromide (CTAB, CAS: 57-09-0, Molar mass = 364.45 g / mol), Ammonia (NH ₄ OH, CAS: 1336 -21-6, Molar mass = 35.05 g / mol and density d = 0.9), N- (Trimethoxysilylpropyl) Ethylenediaminetriacetate, trisodium salt (COOH-TMOS, CAS: 128850-89-5, Molar mass = 462, 42 g / mol and density d = 1.26).
Procedure: In a plastic bottle are mixed 0.64 g of activated carbon W35, 0.29 g of CTAB and 150 ml of an aqueous solution of NH ₄ OH previously prepared at a concentration of 2.048M. The solution is left under magnetic stirring at room temperature for 1 h. 20 μL of COOH-TMOS are then added followed by 6.5 ml of ethanolic TEOS at a concentration of 1.55 mM and the solution is left under stirring for another hour at room temperature. The stirring is then stopped and the solution is left to mature overnight at 50 ° C. The solution is then recovered by centrifugation (12,000 rpm for 12 min). The surfactant is removed by a succession of washing with hydrochloric acid and ethanol before being stored in the latter. Before use, the materials are recovered by centrifugation (12,000 rpm for 12 min) then dried in an oven at 60 ° C for 2 h.
EXAMPLE 4 Synthesis of Activated Charcoals Coated with Silica Functionalized with Aromatic Groups
Reagents: Activated Carbon W35 (SOFRALAB), Tetraethyl orthosilicate (TEOS, CAS: 78-10-4, Molar mass = 208.33 g / mol and density d = 0.933), Methanol (MeOH, CAS: 67-56-1, Molar mass = 32.04 g / mol and density d = 0.791), Cetyltrimethylammonium bromide (CTAB, CAS: 57-09-0, Molar mass = 364.45 g / mol), Ammonia (NH ₄ OH, CAS: 1336 -21-6, Molar mass = 35.05 g / mol and density d = 0.9), Trimethoxyphenylsilane (Ar-TMOS, CAS: 2996-921, Molar mass = 198.29 g / mol and density d = 1.062) .
Procedure: In a plastic bottle are mixed 0.64 g of activated carbon W35, 0.29 g of CTAB and 150 ml of an aqueous solution of NH ₄ OH previously prepared at a concentration of 2.048M. The solution is left under magnetic stirring at room temperature for 1 h. 20 μL of Ar-TMOS are then added followed by 6.5 ml of ethanolic TEOS at a concentration of 1.55 mM and the solution is left under stirring for another hour at room temperature. The stirring is then stopped and the solution is left to mature overnight at 50 ° C. The solution is then recovered by centrifugation (12,000 rpm for 12 min). The surfactant is removed by a succession of washing with hydrochloric acid and ethanol before being stored in the latter. Before use, the materials are recovered by centrifugation (12,000 rpm for 12 min) then dried in an oven at 60 ° C for 2 h.
Example 5 Synthesis of Activated Charcoals Coated with Functionalized Silica with Urea Groups
Reagents: Activated Carbon W35 (SOFRALAB), Tetraethyl orthosilicate (TEOS, CAS: 78-10-4, Molar mass = 208.33 g / mol and density d = 0.933), Methanol (MeOH, CAS: 67-56-1, Molar mass = 32.04 g / mol and density d = 0.791), Cetyltrimethylammonium bromide (CTAB, CAS: 57-09-0, Molar mass = 364.45 g / mol), Ammonia (NH4OH, CAS: 1336-21 -6, Molar mass = 35.05 g / mol and density d = 0.9), 3- (4-Semicarbazidyl) propyltriethoxysilane (SCPTS, CAS: 106868-88-6, Molar mass = 279.41 g / mol and density d = 1.08).
Procedure: In a plastic bottle are mixed 0.64 g of activated carbon W35, 0.29 g of CTAB and 150 ml of an aqueous solution of NH4OH previously prepared at a concentration between 1 and 3 mol.L ¹ , preferably 2.05 mol.L ¹ . The solution is left under magnetic stirring at room temperature for 1 h. 20 μL of Ur-TEOS are then added, followed by 6.5 ml of ethanolic TEOS prepared at a concentration between 1 and 2 mmol.L ¹ , preferably 1.55 mmol.L ^1, and the solution is left stirring for another hour at ambient temperature. The stirring is then stopped and the solution is left to mature overnight at 50 ° C. The solution is then recovered by centrifugation (12,000 rpm for 12 min). The surfactant is removed by a succession of washing with hydrochloric acid and ethanol before being stored in the latter. Before use, the materials are recovered by centrifugation (12,000 rpm for 12 min) then dried in an oven at 60 ° C for 2 h.
During syntheses, 3- (4-Semicarbazidyl) propyltriethoxysilane was also used as a precursor for functionalization by urea groups. This can be substituted by any triethoxy or methoxy silane carrying one or more urea groups such as Γ ureidopropyltriethoxy silane.
B. Synthesis of activated carbon coated with silica according to the second embodiment
Example 6 Synthesis of Active Charcoals in Rods Coated with Silica Functionalized with Amine Groups
Reagents: Norit RBBA-3 Activated Carbon in sticks (Sigma-Aldrich), Tetramethyl orthosilicate (TMOS, CAS:, 681-84-5, purity: 99%, Molar mass = 152.22 g / mol and density d = 1.023) , Methanol (MeOH, CAS: 67-56-1, purity 99.9%, Molar mass = 32.04 g / mol and density d = 0.791 g / cm ³ ), 3-aminopropyltriethoxysilane (APTES, CAS 919-30- 2 :, 99% purity, molar mass = 221.37 g / mol and density d = 0.946). Ultra-pure deionized water.
Procedure: 10.23 mL of TMOS and 0.5 mL of APTES are added to a 60 mL bottle containing 14.22 mL of methanol. The mixture is left under stirring to obtain a homogeneous solution. 5.05 mL of water is added to the mixture and the solution is stirred vigorously. The molar proportions of the mixture thus obtained is TMOS / APTES / MeOH / water = 0.97 / 0.03 / 5/4. The gelling soil after 8 min, one to three flows are made after 1 min on sticks of activated carbon positioned on a sieve. The sticks covered with a film of sol-gel material are dried in an oven at 80 °.
Examples 7A and 7B: Synthesis of active carbon sticks coated with functionalized silica with amine groups
Reagents: Norit RBBA-3 Activated Carbon (Sigma-Aldrich), Tetramethyl orthosilicate (TMOS, CAS:, 681-84-5, Molar mass = 152.22 g / mol and density d = 1.023), Ethanol (EtOH, CAS: 64-17-5, Molar mass = 46.07 g / mol and density d = 0.789), 3-aminopropyltriethoxysilane (APTES, CAS 91930-2 :, Molar mass = 221.37 g / mol and density d = 0.946).
Procedure: 9.86 mL of TMOS and 0.99 mL of APTES are added to a 60 mL bottle containing 14.13 mL of ethanol. The mixture is left under stirring to obtain a homogeneous solution. 5.02 mL of water is added to the mixture and the solution is stirred vigorously. The molar proportions of the mixture thus obtained is TMOS / APTES / EtOH / water = 0.94 / 0.06 / 5/4. The soil gelling after 8 min, pouring is carried out after 1 min on activated carbon sticks positioned on a sieve (material 6A). (mass of activated carbon 0.7428 g).
The remaining soil is left to mature for an additional 2 minutes, at the end of which a new pouring is carried out on new rods of activated carbon (material 6B) (mass of activated carbon 0.7315 g). The sticks covered with a film of sol-gel material are dried in an oven at 80 °.
C. Synthesis of hybrid activated carbon coated with functionalized silica by simple mixing of a sol and activated carbon according to the second embodiment
Example 8 Synthesis of Hybrid Materials by Mixing Active Carbon with a Sol of Precursor Silicon One of which is Functionalized with Acetoxy Groups
Reagents: Darco KG-B (Sigma-Aldrich) Activated Carbon powder, Tetramethyl orthosilicate (TMOS, CAS:, 681-84-5, 99% purity, Molar mass = 152.22 g / mol and density d = 1.023), methanol (MeOH, CAS: 67-56-1, purity 99.9%, Molar mass = 32.04 g / mol and density d = 0.791) ,, Acetoxyethyltrimethoxysilane (AETMS, CAS: 72878-29-6, purity 95% , Molar mass = 250.36 g / mol and density d = 0.983), ultra-pure deionized water, 28% aqueous ammonia solution.
Procedure: 10.29 mL of TMOS and 0.55 mL of AETMS are added to a 60 mL bottle containing 14.13 mL of methanol. The mixture is left under stirring to obtain a homogeneous solution. 4.73 mL of water is added to the mixture with stirring and 0.3 mL of a 28% aqueous ammonia solution is added last. The activated carbon (0.7514 g) is added 20 s after with vigorous stirring for 10 s, then the soil is poured into a honeycomb mold. The molar proportions of the mixture thus obtained is TMOS / AETMS / MeOH / water = 0.98 / 0.02 / 5/4 with a NH4OH concentration of 0.148 M. After gelling, the mold is dried under inert gas flow. After demolding, black granules of cylindrical shape are obtained with dimensions 0.7 (L) * 0.3 (diameter) cm.
Example 9 Synthesis of Hybrid Materials by Mixing Activated Carbon with a Sol of Precursor Silicon One of which is Functionalized with Acetoxy Groups
Same synthesis as in Example 8. The activated carbon is in powder form, Activated Carbon W35 (SOERALAB) (0.7539 g)
Example 10 Synthesis of Hybrid Materials by Mixing Active Carbon with a Sol of Precursor Silicon, One of Which Is Functionalized with Glycidylloxy Groups
Reagents: Darco KG-B (Sigma-Aldrich) Activated Carbon powder, Tetramethyl orthosilicate (TMOS, CAS:, 681-84-5, 99% purity, Molar mass = 152.22 g / mol and density d = 1.023), (MeOH, CAS: 67-56-1, purity 99.9%, Molar mass = 32.04 g / mol and density d = 0.791), 3glycidyloxypropylltriethoxysilane (GPTES, CAS: 2602-34-8, Molar mass = 278, 42 g / mol and density d = 1.004). ultra-pure deionized water, 28% aqueous ammonia solution.
Procedure: 10.25 mL of TMOS and 0.59 mL of GPTES are added to a 60 mL bottle containing 14.13 mL of methanol. The mixture is left under stirring to obtain a homogeneous solution. 4.73 mL of water is added to the mixture with stirring and 0.3 mL of a 28% aqueous ammonia solution is added last. The activated carbon (0.7505 g) is added 20 s after with vigorous stirring for 10 s, then the soil is poured into a honeycomb mold. The molar proportions of the mixture thus obtained is TMOS / GPTES / MeOH / water = 0.967 / 0.023 / 5/4 with a concentration of NH4OH of 0.148 M. After gelling, the mold is dried under inert gas flow. After demolding, black granules of cylindrical shape are obtained with dimensions 0.7 (L) * 0.3 (diameter) cm.
Example 11 Synthesis of Hybrid Materials by Mixing Activated Charcoals with a Sol of Silicon Precursors, One of Which is Functionalized with Glycidylloxy Groups
Same synthesis as in Example 10. The activated carbon is in this case in powder form, Activated Carbon W35 (SOERALAB) (0.7527 g).
Example 12 Synthesis of Hybrid Materials by Mixing Activated Charcoals with a Sol of Silicon Precursors, One of Which is Functionalized with Amide and Amine Groups
Reagents: Darco KG-B (Sigma-Aldrich) Activated Carbon powder, Tetramethyl orthosilicate (TMOS, purity 99%, CAS:, 681-84-5, Molar mass = 152.22 g / mol and density d = 1.023), (MeOH, CAS: 67-56-1, purity 99.9%, Molar mass = 32.04 g / mol and density d = 0.791), 33061708 (4'semicarbazido) propyltriethoxysilane (SCPTS), CAS: 106868-88- 6, purity 95%,, Molar mass =
279.41 g / mol and density d = 1.08). ultra-pure deionized water, 28% aqueous ammonia solution.
Procedure: 10.27 mL of TMOS and 0.56 mL of SCPTS are added to a 60 mL bottle containing 14.14 mL of methanol. The mixture is left under stirring to obtain a homogeneous solution. 4.73 mL of water is added to the mixture with stirring and 0.3 mL of a 28% aqueous ammonia solution is added last. Activated carbon 0.7506 g) is added 20 s after with vigorous stirring for 10 s, then the soil is poured into a honeycomb mold. The molar proportions of the mixture thus obtained is TMOS / SCPTS / MeOH / water = 0.977 / 0.023 / 5/4 with a concentration of NH4OH of 0.148 M. After gelling, the mold is dried under inert gas flow. After demolding, black granules of cylindrical shape are obtained with dimensions 0.7 (L) * 0.3 (diameter) cm.
Example 13 Synthesis of Hybrid Materials by Mixing Activated Charcoals with a Sol of Silicon Precursors, One of Which is Functionalized with Amide and Amine Groups
Same synthesis as in example 12.. The activated carbon is in this case in powder form, Activated Carbon W35 (SOFRALAB) (0.7507 g).
Example 14 Synthesis of Hybrid Materials by Mixing Activated Charcoals with a Sol of Silicon Precursors, One of Which is Functionalized with Aromatic Groups (PhTMOS)
Reagents: Darco KG-B (Sigma-Aldrich) Activated Carbon powder, Tetramethyl orthosilicate (TMOS, purity 99%, CAS:, 681-84-5, Molar mass = 152.22 g / mol and density d = 1.023), (MeOH, CAS: 67-56-1, purity 99.9%, Molar mass = 32.04 g / mol and density d = 0.791), (PhTMOS), CAS: 2996-92-1, purity 98%, Mass molar = 198.29 g / mol and density d = 1.062 g / cm ³ ). ultrapure deionized water, 28% aqueous ammonia solution.
Procedure: 10.27 mL of TMOS and 0.4 mL of PhTMOS are added to a 60 mL flask containing 14.25 mL of methanol. The mixture is left under stirring to obtain a homogeneous solution. 4.78 mL of water is added to the mixture with stirring and 0.3 mL of a 28% aqueous ammonia solution is added last. Activated carbon (0.75 g) is added 20 s after, with vigorous stirring for 10 s, then the soil is poured into a honeycomb mold. The molar proportions of the mixture thus obtained is TMOS / PhTMOS / MeOH / water = 0.977 / 0.023 / 5/4 with a NH4OH concentration of 0.148 M. After gelling, the mold is dried under inert gas flow. After demolding, black cylindrical granules of dimensions 0.7 (L) * 0.3 (diameter) cm are obtained.
Example 15 Synthesis of Hybrid Materials by Mixing Activated Charcoals with a Sol of Precursor Silicon One of which is Functionalized with Aromatic Groups (PhTEOS)
Reagents: Darco KG-B (Sigma-Aldrich) Activated Carbon powder, Tetramethylorthosilicate (TMOS, purity 99%, CAS:, 681-84-5, Molar mass = 152.22 g / mol and density d = 1.023), ( MeOH, CAS: 67-56-1, purity 99.9%, Molar mass = 32.04 g / mol and density d = 0.791), (PhTEOS), CAS: 780-69-8, purity 98%, Molar mass = 240.37 g / mol and density d = 0.996 g / cm ³ . ultra-pure deionized water, 28% aqueous ammonia solution.
Procedure: In a 60 mL bottle containing 14.2 mL of methanol, 10.23 mL of TMOS and 0.52 mL of PhTEOS are added, the mixture is left under stirring to obtain a homogeneous solution. 4.75 mL of water is added to the mixture with stirring and 0.3 mL of a 28% aqueous ammonia solution is added last. Activated carbon (0.75 g) is added 20 s after, with vigorous stirring for 10 s, then the soil is poured into a honeycomb mold. The molar proportions of the mixture thus obtained is TMOS / PhTEOS / MeOH / water = 0.977 / 0.023 / 5/4 with a concentration of NH4OH of 0.148 M. After gelling, the mold is dried under inert gas flow. After demolding, black granules of cylindrical shape are obtained with dimensions 0.7 (L) * 0.3 (diameter) cm.
Example 16 Synthesis of Hybrid Materials by Mixing Active Carbon with a Sol of Precursor Silicon One of which is Functionalized with Amine Groups
Reagents: Darco KG-B (Sigma-Aldrich) Activated Carbon powder, Tetramethylorthosilicate (TMOS, purity 99%, CAS:, 681-84-5, Molar mass = 152.22 g / mol and density d = 1.023), ( MeOH, CAS: 67-56-1, purity 99.9%, Molar mass = 32.04 g / mol and density d = 0.791), 3 aminopropyltriethoxysilane (APTES, CAS 919-30-2, Molar mass = 221.37 g / mol and density d = 0.946), ultra-pure deionized water
Procedure: 17.07 mL of TMOS and 0.833 mL of APPTES are added to a 100 mL flask containing 23.67 mL of methanol. The mixture is stirred to obtain a homogeneous solution. 8.43 mL of water is added to the mixture with stirring. Activated charcoal (0.5152 g) is added 1 min afterwards with vigorous stirring for 30 s, then the soil is poured into a honeycomb mold. The molar proportions of the mixture thus obtained is TMOS / APTES / MeOH / water = 0.977 / 0.023 / 5/4. After gelation, the mold is dried under an inert gas flow. After demolding, black granules of cylindrical shape are obtained with dimensions 0.6 (L) * 0.3 (diameter) cm.
Example 17 Synthesis of Hybrid Materials by Mixing Active Carbon with a Sol of Precursor Silicon, One of Which Is Functionalized with Amine Groups
Same synthesis as in Example 16. The activated carbon is in this case in powder form, Activated Carbon W35 (SOFRALAB) (0.5159 g).
D. Characterization of materials
Transmission Electron Microscopy
In order to highlight the fact that the activated carbon is completely coated (encapsulated) with a layer of nanoporous sol-gel material, the materials prepared in Examples 1 to 5 were characterized by transmission electron microscopy (TEM).
The MET grids are prepared as follows: 1 mg of materials is suspended in 1 ml of ethanol and then vortexed for a few seconds. 10 μL of solution are placed on a grid and the grid is left to air dry for a few minutes before use.
The MET images of the activated carbon W35 (FIG. 3) and of the various materials synthesized in Examples 1 to 5 show that the active carbon is completely covered with the sol-gel material, thus demonstrating the production of a hybrid core-shell material. consisting of an activated carbon core surrounded by a sol-gel material (Figures 2A, 2B, 4A, 4B, 5, 6, 7 and 8).
MET images of activated carbon encapsulated in different functionalized sol-gel silicas show that the addition of a silica co-precursor allows the adhesion of silica nanoparticles around the materials in addition to their covering by the latter.
Scanning Electron Microscopy (SEM) is a powerful technique for observing the topography of surfaces. It is mainly based on the detection of secondary electrons emerging from the surface under the impact of a very fine brush of primary electrons which scans the observed surface and makes it possible to obtain images with a separating power often less than 5 nm and a great depth of field. The instrument makes it possible to form an almost parallel, very fine brush (up to a few nanometers), of electrons strongly accelerated by adjustable voltages from 0.1 to 30 keV, to focus it on the area to be examined and to sweep it gradually. Appropriate detectors collect significant signals when scanning the surface and form various meaningful images. The images of the samples were taken with the SEM "Ultra 55" from Zeiss. Conventionally, the samples are observed directly without any particular deposit (metal, carbon).
Figure 9 shows the SEM images of an activated carbon stick covered with a thin film of sol-gel material and the successive enlargements of the surface showing the cracks in the silicate layer.
Infrared spectroscopy
Fourier Transform InfraRed spectroscopy (Fourier Transform InfraRed spectroscopy) is an analytical technique useful for determining, identifying or confirming the structure of known and unknown products. An infrared spectrum makes it possible to easily highlight the presence of certain functional groups, and can serve as a "spectroscopic identity card" for a molecule or a material. The ATR (Attenuated Total Reflectance) module is installed on the IR spectrometer (Figure 10). This principle consists in bringing a crystal (ZnSe or diamond) into contact with the sample to be analyzed. The IR beam propagates in the crystal; if the refractive index of the crystal is higher than that of the sample, then the beam undergoes total reflections beyond a certain angle of incidence at the sample / crystal interface with the exception of a wave , called evanescent wave which emerges from the crystal and is absorbed by the sample. It is this evanescent wave which is responsible for the IR spectrum observed. The penetration depth is of the order of 1 to 2 micrometers, which therefore provides surface information. This is particularly interesting for the analysis of pure samples (without dilution in a KBr matrix) since the risk of seeing the peaks saturate is very low. In addition, at low energies, the resolution is generally better than for a “classic” spectrum in transmission. These IR spectra were performed with the FTIR-ATR “Alpha-P” module from Bruker.
These infrared spectra of the various materials synthesized in Examples 1 to 4 clearly show the presence of silica in the materials by the peak at 1050-1100 cm ¹ corresponding to the vibrations of elongation of the Si-0 bonds (Figures 10-13).
Differential thermal analysis
Thermogravimetric analysis consists of placing a sample in an oven under a controlled atmosphere and measuring mass variations as a function of temperature. The gradual increase in temperature, or temperature ramp, induces the evaporation of the solvents and the proper degradation of each of the organic constituents of the sample. The reduction in mass corresponding to these losses makes it possible to quantify the proportions of each constituent in the material. A TAR - 92-1750 type device from Setaram is used for a double measurement of each sample. The protocol is as follows: approximately 10 mg of monolith are finely ground, weighed and placed in the balance of the apparatus. The whole is placed in the oven and placed under a synthetic air flow of 110 mL.min-1 of F.I.D. quality. The oven initially at 40 ° C is heated to
1500 ° C with a ramp of 50 ° C. min-l. After 10 minutes at 1500 ° C, the temperature is reduced to ambient at a speed of -90 ° C. min '.
FIG. 14 shows the ATG of Example 6. From the losses of material at different temperatures (H 2 O, Aminopropyl chains, CA), it is possible to deduce the mass of the CA and of the silicate whose proportions are 85, 4 and 14.6% respectively for turnover and functionalized silica.
E. Application examples
Application example 1: Adsorption of atrazine by materials
Atrazine was chosen as the first pollutant studied because of its very good adsorption by carbon. The idea was to compare hybrid composite materials with activated carbon. The adsorption capacity of the materials was determined from their suspension in pollutant solutions and from the study of the supernatant over time. For this, 8 mg of materials are placed in a plastic bottle. 60 mL of an aqueous solution containing atrazine at 14 mg / L are added and the solution is stirred at room temperature. 6 mL aliquots are taken over time, centrifuged to remove traces of materials and the supernatant solutions are studied by UV spectroscopy.
Here is the list of materials that have been used:
W35 Charcoal SiO2 Silica nanoparticles W35 + SiO2 Mixture of activated carbon and Silica nanoparticles Example 1 Non-functionalized hybrid Example 2 Hybrid functionalized with amine groups Example 3 Hybrid functionalized by acid groups Example 4 Hybrid functionalized by aromatic groups Example 5 Hybrid functionalized by urea groups Example 13 Hybrid functionalized by urea groups prepared without surfactant Example 14 Hybrid functionalized by aromatic groups prepared without surfactant Example 17 Hybrid functionalized with amine groups prepared without surfactant
Atrazine has a maximum absorbance at 223 nm. After recording this for different contact times between the materials and the pollutants, we converted it to a percentage of adsorption relative to the mother pollutant solution to give Table 2:
Table 2:% of absorption of atrazine
Time (h) W35 SiO2 W35+SÎO2 Example1 Example2 Example3 Example4 Example5 Example13 Example14 Example17 0 0 0 0 0 0 0 0 0 0 0 00.5 94 0 76 80 75 74 80 95 19 17 24 % adsorption 1 95 0 82 80 79 78 85 97 21 18 27 atrazine2 97 0 84 80 83 83 89 98 22 18 284 #N / A #N / A 87 #N / A #N / A #N / A #N / A 98 23 19 3024 100 0 91 89 86 87 94 99 35 23 35
As expected, activated carbon very quickly and completely traps atrazine. Conversely, silica nanoparticles alone do not trap atrazine at all. The mixture of the two gives a good overall adsorption but is certainly due to the activated carbon alone (Figure 15).
The results of Examples 1 to 5 (Figure 16) and 13, 14 and 17 (Figure 17) clearly show 2 trends. On the one hand, examples 1 to 5 prepared with a surfactant have an adsorption comparable to activated carbon alone, although slightly less effective with rapid and almost complete adsorption. On the other hand, examples 13, 14 and 17 prepared without surfactant exhibit very low adsorption, certainly due to the lack of porosity of the silica allowing the atrazine to penetrate into the materials.
For this example of application, the functionalization of the materials does not seem to have an impact whatsoever with the materials prepared with or without surfactant
Application example 2: Adsorption of atrazine by the materials corresponding to examples 6 to 7A and 7B
Absorption tests were carried out with the materials corresponding to exemplex 6, 7A and 7B. Two granules were placed in the presence of atrazine solutions at 10.65 mg.L ¹ . The granules were introduced into a flask containing 100 ml of the atrazine solution and a magnetic bar and placed under magnetic stirring. The residual absorbance of atrazine was measured at different intervals. FIG. 18 makes it possible to compare the adsorption rates of atrazine by the Norrit RBBA-3 activated carbon alone or coated with a layer of material from Example 6.
Table 3 summarizes the values of the adsorption rates of atrazine normalized with respect to the mass of activated carbon of each material. Even if the sticks coated with sol-gel material seem to have a better efficiency for the adsorption of atrazine, the adsorption rates are very low compared to the materials obtained with surfactant.
Table 3: Adsorption rates of atrazine
Sample functionalization Adsorption rate (H ¹ ) Mass of CA(mg) Normalized speed(H v) CA Norrit RBBA-33.32 10 ³ 81.05 4.10 10 ² Example 6 TMOS / APTES 0.97 / 0.03 soil maturation: 1min 5.06 10 ³ 79.88 6.33 10 ² Example 7 A TMOS / APTES 0.9 / 0.06 soil maturation: 1 min 4.37 10 ³ 76.39 5.72 10 ² Example 7B TMOS / APTES 0.94 / 0.06 soil maturation: 3 min 3.45 10 ³ 80.34 4.29 10 ²
Application example 3: Adsorption of acetone by materials
Acetone is part of the range of very small pollutants which in theory are not retained by Activated Carbon. The adsorption capacity of the materials was determined from their suspension in pollutant solutions and from the study of the supernatant over time. For this, 8 mg of materials are placed in a plastic bottle. 60 mL of an aqueous solution containing acetone at 10 g / L are added and the solution is stirred at room temperature. 10 6 ml aliquots are taken over time, centrifuged to remove traces of materials and the supernatant solutions are studied by UV spectroscopy.
Here is the list of materials that have been used:
W35 Charcoal SiO2 Silica nanoparticles W35 + SiO2 Mixture of activated carbon and Silica nanoparticles Example 1 Non-functionalized hybrid Example 2 Hybrid functionalized with amine groups Example 3 Hybrid functionalized by acid groups Example 4 Hybrid functionalized by aromatic groups Example 5 Hybrid functionalized by urea groups Example 13 Hybrid functionalized by urea groups prepared without surfactant Example 14 Hybrid functionalized by aromatic groups prepared without surfactant Example 17 Hybrid functionalized with amine groups prepared without surfactant
Acetone has a maximum absorbance at 265 nm. After recording this for different contact times between the materials and the pollutants, we converted it to a percentage of adsorption relative to the mother pollutant solution to give Table 4:
Table 4: Percentages of acetone absorption
Time (h) W35 SÎO2 W35+SÎO2 Example1 Example2 Example3 Example4 Example5 Example13 Example14 Example170 0 0 0 0 0 0 0 0 0 0 00.5 3 4 6 3 3 4 3 18 4 2 1 % adsorption 1 3 4 7 3 5 4 4 22 2 1 1 acetone 2 4 4 6 2 7 5 4 25 1 2 04 #N / A #N / A #N / A #N / A #N / A #N / A #N / A 28 4 4 324 5 4 7 26 59 22 13 40 8 5 848 6 5 13 52 77 48 36 51 10 10 10
As expected, carbon alone, like silica nanoparticles alone, does not trap acetone (Figure 19). After 48 hours in suspension, the percentage of adsorption is only 6 and 5% respectively. The physical mixture of the two gives the same result for 24 hours with a slight improvement after 48 hours.
In the case of Examples 13, 14 and 17 (FIG. 21), prepared without surfactant, it can be seen that the adsorption of acetone is not very effective. This phenomenon is surely linked to the fact that there was no silica-induced porosity.
For Examples 1 to 5 (Figure 20), prepared with a surfactant, there are several behaviors related to the functionalization of the latter. In the majority of materials, an average adsorption of around 50% is observed. However, in the case of Example 2, functionalized with amine groups, there is a strong adsorption of the materials up to 77%. The possibility of forming hydrogen bonds between the amine functions of the material and acetone will promote the adsorption of the latter thanks to these weak interactions.
Application example 4: Adsorption of acetaldehyde by materials
Acetaldehyde is part of the range of very small pollutants which in theory are not retained by activated carbon. The adsorption capacity of the materials was determined from their suspension in pollutant solutions and from the study of the supernatant over time. For this, 8 mg of materials are placed in a plastic bottle. 60 mL of an aqueous solution containing acetone at 11 g / L are added and the solution is stirred at room temperature. 6 mL aliquots are taken over time, centrifuged to remove traces of materials and the supernatant solutions are studied by UV spectroscopy.
Here is the list of materials that have been used:
W35 Charcoal SiO2 Silica nanoparticles W35 + SiO2 Mixture of activated carbon and Silica nanoparticles Example 1 Non-functionalized hybrid Example 2 Hybrid functionalized with amine groups Example 3 Hybrid functionalized by acid groups Example 4 Hybrid functionalized by aromatic groups Example 5 Hybrid functionalized by urea groups Example 13 Hybrid functionalized by urea groups prepared without surfactant Example 14 Hybrid functionalized by aromatic groups prepared without surfactant Example 17 Hybrid functionalized with amine groups prepared without surfactant
Acetaldehyde has a maximum absorbance at 278 nm. After recording this for different contact times between the materials and the pollutants, we converted it into 5 percentage adsorption compared to the mother pollutant solution to give Table 5:
Table 5: Percentages of acetaldehyde adsorption
Time (h) W35 SÎO2 W35 Example5 Example13 Example14 Example17 +SiO2 Example1 Example2 Example3 Example40 0 0 0 0 0 0 0 0 0 0 00.5 1 0 1 2 2 2 1 4 4 2 4 % adsorption 1 1 0 0 4 0 -1 -4 4 3 3 3 acetaldehyde4 3 2 2 7 -1 -1 -2 8 4 6 524 4 4 10 10 10 14 9 22 10 13 648 3 3 #N / A 15 30 25 23 #N / A #N / A #N / A #N / A72 7 5 #N / A 16 62 44 48 58 14 17 11
The percentage of adsorption of activated carbon alone, silica nanoparticles alone and the physical mixture of the two is very low as expected even after 72 hours (Figure 22).
Once again, we note a very weak adsorption of examples 13, 14 and 17 (Figure
24), prepared without surfactant. On the other hand, for the first time, a weak adsorption is also noted for example 1 (Figure 23) prepared with CTAB but without additional functionalization. Indeed, after 72 hours, Example 1 shows only 16% of adsorption of acetaldehyde.
However, Examples 2 to 5 (Figure 23), possessing additional functional groups, demonstrate the usefulness of the latter by a very marked increase in adsorption between 44 and 62% demonstrating the utility of a functionalization for improving more specific targeting of pollutants.
Application example 5: Adsorption of methiocarb by materials
Methiocarb, like atrazine, is one of the medium-sized molecules that can be easily adsorbed by activated carbon. This example constitutes a second test to compare our materials with activated carbon in its optimal conditions. The adsorption capacity of the materials was determined from their suspension in pollutant solutions and from the study of the supernatant over time. For this, 8 mg of materials are placed in a plastic bottle. 60 mL of an aqueous solution containing acetone at 10 mg / L are added and the solution is stirred at room temperature. 6 mL aliquots are taken over time, centrifuged to remove traces of materials and the supernatant solutions are studied by UV spectroscopy.
Here is the list of materials that have been used:
W35 Charcoal SiO2 Silica nanoparticles W35 + SiO2 Mixture of activated carbon and Silica nanoparticles Example 1 Non-functionalized hybrid Example 2 Hybrid functionalized with amine groups Example 3 Hybrid functionalized by acid groups Example 4 Hybrid functionalized by aromatic groups Example 5 Hybrid functionalized by urea groups Example 13 Hybrid functionalized by urea groups prepared without surfactant Example 14 Hybrid functionalized by aromatic groups prepared without surfactant Example 17 Hybrid functionalized with amine groups prepared without surfactant
Methiocarb has a maximum absorbance at 262 nm. After recording this for different contact times between materials and pollutants, we converted it to a percentage of adsorption relative to the mother pollutant solution to give Table 6:
Table 6: adsorption percentages of methiocarb
% Time (h) W35 SiO2 W35+SÎO2 Example1 Example2 Example3 Example4 Example5 Example13 Example14 Example17 adsorption 0 0 0 0 0 0 0 0 0 0 0 0 methiocarb3 100 6 40 99 86 93 84 88 3 13 524 102 12 45 97 87 96 89 91 4 21 3
The adsorption of methiocarb by activated carbon follows the expected behavior with complete adsorption after only 3 hours. This behavior is found for example 1. In the case of SiO2 (FIG. 25), it can be seen that the adsorption is very low, just like examples 13, 14 and 17 (FIG. 27), prepared without surfactant, binding the adsorption on access to the porosity of activated carbon.
Finally, as for atrazine, examples 2 to 5 (Figure 26) showed a behavior very close to Activated Carbon with almost complete adsorption after 3 hours.
Application example 6: Filter system
A model filtering system has been implemented. This system consists of a syringe in which the hybrid material is trapped between two cotton filters and through which the solution containing the pollutant must pass (Figure 31).
Between the two filters, we inserted 5 mg of Example 1 and we poured 10 mL of 20 mg / L atrazine solution. The collected liquid was then passed directly by UV-visible spectroscopy (Varian 300 spectrometer). This operation was repeated a second time to check that the filter was still adsorbing. The data obtained by spectroscopy are presented in Figure 28.
It is observed that for the first 10 milliliters as much as for the following 10, the atrazine is completely adsorbed by Example 1 (Figure 28). In addition, a parallel study was carried out without materials to see the absorption capacity of the filters alone. This study showed that the filters used do not absorb atrazine and therefore do not influence our results.
Application example 8: Filter system for the adsorption of methiocarb
The materials of examples 8 to 13 are tested in dynamic mode. The results are shown in FIGS. 29 and 30.
It is observed that even if a dynamic treatment contributes to accelerate the absorption of methiocarb, these hybrid materials are however less efficient than the corresponding activated carbon.
Application example 9: Tests for air pollution control
An example of the use of Example 4 is shown for the retention of toluene. A drilling curve for the material was made (Figure 32). For this purpose, a 10 mL syringe, fitted with 2 tips, is filled with 100 mg of Example 4, then is exposed to a flow of 350 mL / min of a gas mixture (N2 + toluene) containing 1 ppm. (3.77 mg / m3) of toluene. The toluene content upstream of the syringe is measured and that downstream is monitored over time. The measurement of the toluene content is carried out with a PID detector, ppbRAE.
The piercing curve, shown below, indicates that the nanoparticles alone retain very little toluene. In fact, traces of the latter are observed from the first minutes of the experiment and the concentration of toluene bases is found at the outlet of syringes after 7 p.m.
In the case of Activated Carbon alone (Figure 33), it completely adsorbs toluene for 83 hours before allowing it to pass gradually. It is only after 151 hours that the same concentration of toluene is observed at the outlet as at the inlet of the syringe.
Finally, in the case of Example 4 (FIG. 35), it can be seen on the piercing curve that the appearance of toluene at the outlet of the syringe only occurs after 123 hours and that the original concentration of toluene n 'is found only after 178h. This result shows that our materials have a much higher adsorption capacity than activated carbon alone and are useful in possible applications as an air filter.
FIG. 35 makes it possible to compare the trapping efficiencies of toluene of the different materials.
References [1] WHO / UNICEF (2014) Progress on drinking-water and sanitation - 2014 update. Geneva, W. H. O.
[2] Dôrfliger, N .; Perrin, J. Geosciences 2011, 13, 94.
[3] Order of January 11, 2007 relating to the limits and quality references of raw water and water intended for human consumption mentioned in articles R. 1321-2, R.
[4] Lennetech sheet with list of compounds trapped by activated carbon in decreasing order of efficiency, http://www.lenntech.fr/bibliotheque/adsorption/adsorption.htm [5] Filter medium for removal of sodium from drinking water and preparation method thereof, L., Yuntang; Pu, Jian; Sun, Shujun, Faming Zhuanli Shenqing (2011), CN 102059022 A [6] Static and dynamic combined water purifier with multi-stage filter bed cyclone magnetization, WY, Faming Zhuanli Shenqing, (2014), CN 104058542 A [7] Preparation of filter medium useful for removing synthetic musk from drinking water, a. i. u. i. w. d., Zhou, Qidi; Luan, Yuntang, Faming Zhuanli Shenqing (2012), CN 102350323 A [8] Molded activated charcoal and water purifier involving same, Y., Hiroe; Arita, Satoru; Kawasaki, Shuji, PCT Int. Appl. (2011), WO 2011016548 Al [9] Youji Li, Jun Chen, Jianben Liu, Mingyuan Ma, Wei Chen, Leiyong Li, Activated carbon supported TiO2-photocatalysis doped with Fe ions for continuous treatment of dye wastewater in a dynamic reactor, Journal of Environmental Sciences 2010, 22 (8) 1290-1296.
[10] K.Y. Foo, B.H. Hameed, Decontamination of textile wastewater via TiO2 / activated carbon composite materials, Advances in colloid and interface science 159 (2010) 130-143.
[11] Meltem Asiltürk, Sadiye Sener, TiO2-activated carbon photocatalysts: Preparation, characterization and photocatalytic activities, Chemical Engineering Journal 180 (2012) 354-363.
[12] Hongmei Hou, Hisashi Miyafuji, Haruo Kawamoto, Supercritically treated TiO2-activated carbon composites for cleaning ammonia, Journal of wood science 53 (2006) 533-538.
[13] Biao Huang, Shiro Saka, Photocatalytic activity of TiO2 crystallite-activated carbon composites prepared in supercritical isopropanol for the décomposition of formaldehyde, Journal of wood science 49 (2003) 79-85.
[14] Juan Zhang, Dishun Zhao, Jinlong Wang, Liyan Yang, Photocatalytic oxidation of 5 dibenzothiophene using TiCh / bamboo charcoal, Journal of materials science 44 (2009) 3112-3117.
[15] Karran Woan, Georgios Pyrgiotakis, Wolfgang Sigmund, Photocatalytic carbon-nanotubeTiO ₂ composites, Advanced materials 21 (2009) 2233-2239.
[16] Curdts, B .; Pflitsch, C .; Pasel, C .; Helmich, M .; Bathen, D .; Atakan, B. Novel silica-based adsorbents with activated carbon structureMicroporous and Mesoporous Materials 2015, 210, 202 [17] Guo, X .; Liu, H .; Shen, Y .; Niu, M .; Yang, Y .; Liu, X .; Theoretical and experimental studies on silica-coated carbon spheres composites Applied Surface Science 2013, 283, 215.
[18] RS Rao, K. El-Hami, T. Kodaki, K. Matsushigi, K. Makino, Another method of synthesis of silica nanoparticles, Journal of Colloid and Interface Science, 289 (1), 125-131, (2005 ).
[19] I. Ab Rahman, V. Padavettan, Synthesis of silica nanoparticles by solgel: size-depend properties, surface notifications and applications in silica-polymer nanocomposites-A review, Journal of nanomaterials, Vol 2012, Article ID 132424, doi: 10/1155/2012/132424.

权利要求:
Claims (18)
[1" id="c-fr-0001]
1. A process for preparing a hybrid core-shell material consisting of an activated carbon core surrounded by a shell of a mesoporous sol-gel silica material, said process comprising the formation of a sol-shell silica shell mesoporous gel around activated carbon particles.
[2" id="c-fr-0002]
2. Method according to claim 1, characterized in that the mezoporous sol-gel silica shell is formed from at least one organosilicate precursor chosen from tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), phenyltrimethoxysilane (PhTMOS ), phenyltriethoxysilane (PhTEOS), (2-phenylethyl) triethoxysilane, 3-aminopropyltriethoxysilane (APTES), (3-glycidyloxypropyl) trimethoxysilane (GPTMOS), (3glycidyloxypropyl) triethoxysilane (GPTES) Aminoethyl) -3- (trimethoxysilyl) propylamine (NH ₂ -TMOS), N- (Trimethoxysilylpropyl) ethylenediaminetriacetate, racetoxyethyltrimethoxysilane (AETMS), Pureidopropyltriethoxy silane (UPTS), 3- (4-semicarbazidyl) propyl) and .
[3" id="c-fr-0003]
3. Method according to claim 2, characterized in that the organosilicate precursor is tetramethoxysilane or tetraethoxysilane.
[4" id="c-fr-0004]
4. Method according to claim 2, characterized in that the organosilicate precursor is a mixture of tetramethoxysilane and a functionalized organosilicate precursor, advantageously chosen from phenyltrimethoxysilane (PhTMOS), phenyltriethoxysilane (PhTEOS), (2phenylethyl) triethoxysilane 3-aminopropyltriethoxysilane (APTES), (3glycidyloxypropyl) trimethoxysilane (GPTMOS), (3-glycidyloxypropyl) triethoxysilane (GPTES), N- (2-Aminoethyl) -3- (trimethoxysilyl) propylamine (NH ₂ -TMOS), N (Trimethoxysilylpropyl) ethylenediaminetriacetate, acetoxyethyltrimethoxysilane (AETMS), Pureidopropyltriethoxysilane (UPTS), 3- (4-semicarbazidyl) propyltriethoxysilane (SCPTS) and their mixtures.
[5" id="c-fr-0005]
5. Method according to any one of the preceding claims, characterized in that the formation of a mesoporous sol-gel silica shell around activated carbon particles comprises:
a) the formation of a shell of sol-gel nanoparticles around activated carbon in basic aqueous solution from at least one organosilicate precursor, the aqueous solution containing Γ ammonia (NH ₄ 0H) and a surfactant,
b) recovery of the activated carbon surrounded by the shell of sol-gel material prepared in step a),
c) the elimination of any residual surfactant from the activated carbon surrounded by the shell of sol-gel material to release the pores of the sol-gel material formed in step a), and characterized in that in step a), a basic aqueous solution containing ammonia, the surfactant and the activated carbon is first supplied, then at least one organosilicate precursor is added, this precursor being dissolved in an organic solvent.
[6" id="c-fr-0006]
6. Method according to claim 5, characterized in that the organic solvent is chosen from linear aliphatic alcohols C1 to C4.
[7" id="c-fr-0007]
7. Method according to claim 6, characterized in that the organic solvent is ethanol.
[8" id="c-fr-0008]
8. Method according to any one of claims 5 to 7, characterized in that the activated carbon is in the form of powder.
[9" id="c-fr-0009]
9. Method according to any one of claims 5 to 8, characterized in that the surfactant is an ionic surfactant.
[10" id="c-fr-0010]
10. Method according to claim 9, characterized in that the surfactant is cetyltrimethylammonium bromide.
[11" id="c-fr-0011]
11. Method according to any one of claims 1 to 4, characterized in that the step of forming the shell of sol-gel nanoparticle of silica comprises the preparation of a sol for mixing at least one organosilicate precursor in an aqueous solution containing an organic solvent followed by coating the activated carbon with this sol.
[12" id="c-fr-0012]
12. The method of claim 11, characterized in that the activated carbon is in the form of rods of millimeter size and the coating thereof is carried out by soaking and then removing the sticks in the ground or pouring the ground on the sticks through a sieve.
[13" id="c-fr-0013]
13. The method of claim 11, characterized in that the activated carbon is in the form of powder and the coating is carried out by adding the activated carbon powder in the soil, then the mixture obtained is poured into molds.
[14" id="c-fr-0014]
14. Hybrid core-shell material consisting of an activated carbon core surrounded by a mesoporous sol-gel silica shell.
[15" id="c-fr-0015]
15. Hybrid core-shell material according to claim 14, characterized in that the shell consists of nanoparticles of mesoporous sol-gel silica.
5
[16" id="c-fr-0016]
16. Hybrid core-shell material according to claim 15, characterized in that the silica nanoparticles are spherical in shape and have a diameter of 20 to 400 nm.
[17" id="c-fr-0017]
17. Use of the hybrid core-shell material according to any one of claims 14 to 16 as a filtering material, in particular for the filtration of air or water.
[18" id="c-fr-0018]
18. Filter system comprising the hybrid core-shell material according to any one of the
10 claims 14 to 16.
1/17
TEOS alone
--------------- ►
Charcoal
Example 1
TEOS + functions
------------>
Charcoal
Examples 1 to 5

类似技术:

---

公开号 | 公开日 | 专利标题

---

FR3061708A1|2018-07-13|PROCESS FOR PREPARING HEART-SHELL HYBRID MATERIALS

---

Kumar et al.2012|Equilibrium and kinetic studies on biosorption of 2, 4, 6-trichlorophenol from aqueous solutions by Acacia leucocephala bark

---

Pourebrahim et al.2017|Simultaneous removing of Pb2+ ions and alizarin red S dye after their complexation by ultrasonic waves coupled adsorption process: Spectrophotometry detection and optimization study

---

Zenasni et al.2014|Adsorption of Congo red from aqueous solution using CTAB-kaolin from Bechar Algeria

---

FR2998891A1|2014-06-06|PROCESS FOR PREPARING A GLASS WITH BIMODAL POROSITY, POSSIBLY FUNCTIONALIZED AND SAID GLASS

---

EP3393975B1|2020-04-15|New nanomaterials, method for producing the same and their use

---

Tomina et al.2017|Composite sorbents based on porous ceramic substrate and hybrid amino-and mercapto-silica materials for Ni | and Pb | ions removal

---

Zhang et al.2015|Graphene oxide-based polymeric membranes for broad water pollutant removal

---

Gemeay et al.2018|Immobilization of green synthesized silver nanoparticles onto amino-functionalized silica and their application for indigo carmine dye removal

---

Costa et al.2019|Evaluation of rice husk ash in adsorption of Remazol Red dye from aqueous media

---

Yohai et al.2019|Nanocomposite functionalized membranes based on silica nanoparticles cross-linked to electrospun nanofibrous support for arsenic | adsorption from contaminated underground water

---

Dada et al.2019|Kinetics and thermodynamics of adsorption of rhodamine B onto bentonite supported nanoscale zerovalent iron nanocomposite

---

EP3565925B1|2021-11-10|Process to coat textile materials

---

CN109569500A|2019-04-05|Sour modified meerschaum Biological nanocomposite of loading microorganisms and the preparation method and application thereof

---

Zulfikar et al.2020|Removal of methylene blue from aqueous solution using poly |/SiO2 and functionalized poly |/SiO2 composite nanofibers

---

CA3106068A1|2020-01-16|Odorless lid

---

Sigmund et al.2019|NO 2 and natural organic matter affect both soot aggregation behavior and sorption of S-metolachlor

---

Alotaibi2021|Mesoporous silica nanoparticles modified with stimuli-responsive polymer brush as an efficient adsorbent for chlorophenoxy herbicides removal from contaminated water

---

EP2819954A1|2015-01-07|Use of carbon nanotubes and synthetic mineral clay for the purification of contaminated waters

---

Yohai del Cerro et al.2019|Nanocomposite functionalized membranes based on silica nanoparticles cross-linked to electrospun nanofibrous support for arsenic | adsorption from contaminated underground water

---

Ibrahim et al.2020|REMOVAL OF EOSIN STAIN FROM AQUEOUS SOLUTION BY SUNFLOWER HUSK

---

Seraji et al.2017|Adsorption of phenol by super hydrophobic phenol-formaldehyde/silica hybrid aerogel

---

Romantsova et al.2016|Carbon nanotubes-modified activated carbon as an efficient adsorbent for the removal of methyl orange: Equilibrium and kinetics studies

---

Masoudnia et al.2019|The use of organic-inorganic hybrid nano absorbents SBA-15 functionalized to investigation the removal of arsenic from aquatic environments

---

WO2018069528A1|2018-04-19|Method for sol-gel coating of textile materials

同族专利:

---

公开号 | 公开日

---

WO2018127671A9|2019-05-16|

---

KR20190105040A|2019-09-11|

---

EP3565783A1|2019-11-13|

---

CN110312682A|2019-10-08|

---

WO2018127671A1|2018-07-12|

---

US20190351392A1|2019-11-21|

---

FR3061708B1|2021-10-22|

引用文献:

---

公开号 | 申请日 | 公开日 | 申请人 | 专利标题

---

DE4343358A1|1993-12-18|1995-06-22|Hasso Von Bluecher|Porous adsorbent plate or moulding useful as filter esp. for gas purification|

---

KR20070004228A|2005-07-04|2007-01-09|최성우|Adsorbent for recovering volatile organic compound and manufacturing method the same of|CN112675814A|2020-12-10|2021-04-20|四川大学|Silicon-rich biomass-based biochar/mesoporous silica composite material and preparation method and application thereof|JP6275368B2|2009-08-06|2018-02-07|株式会社クラレ|Activated carbon molded body and water purifier using the same|

---

CN102059022B|2010-11-23|2012-10-03|苏州市维欧泰克精密制造有限公司|Filter medium for removing sodium in drinking water|

---

CN102350323B|2011-08-18|2013-06-05|奇迪电器集团有限公司|Filter medium used for removing artificially synthesized musk in drinking water and manufacturing method thereof|

---

CN104058542B|2013-03-18|2016-12-28|王颖|Sound combines multistage filter bed eddy flow Magnetizing water purifier|CN107188173B|2017-05-17|2020-08-11|安徽省舒城华竹实业有限公司|Preparation method of sulfydryl functionalized mesoporous bamboo charcoal material|

---

FR3083682B1|2018-07-12|2020-12-11|Ethera|ANTI-ODOR COVER|

---

CN109225139A|2018-11-06|2019-01-18|南方科技大学|Urban domestic sewage sludge base weight metal absorbent and preparation method thereof, application|

---

CN112156729B|2020-08-25|2021-10-12|安徽壹石通材料科技股份有限公司|Preparation method of silicon oxide/carbon composite structure microspheres|

法律状态:
2018-01-29| PLFP| Fee payment|Year of fee payment: 2 |

---

2018-07-13| PLSC| Publication of the preliminary search report|Effective date: 20180713 |

---

2019-01-30| PLFP| Fee payment|Year of fee payment: 3 |

---

2020-01-27| PLFP| Fee payment|Year of fee payment: 4 |

---

2021-01-25| PLFP| Fee payment|Year of fee payment: 5 |

---

2021-12-28| PLFP| Fee payment|Year of fee payment: 6 |

优先权:

---

申请号 | 申请日 | 专利标题

---

FR1750145|2017-01-06|

---

FR1750145A|FR3061708B1|2017-01-06|2017-01-06|PROCESS FOR PREPARING HEART-SHELL HYBRID MATERIALS|FR1750145A| FR3061708B1|2017-01-06|2017-01-06|PROCESS FOR PREPARING HEART-SHELL HYBRID MATERIALS|

---

KR1020197023045A| KR20190105040A|2017-01-06|2018-01-08|Methods of Making Core-Shell Hybrid Materials|

---

EP18700794.3A| EP3565783A1|2017-01-06|2018-01-08|Method for producing core-shell hybrid materials|

---

US16/476,166| US20190351392A1|2017-01-06|2018-01-08|Method for producing core-shell hybrid materials|

---

PCT/FR2018/050030| WO2018127671A1|2017-01-06|2018-01-08|Method for producing core-shell hybrid materials|

---

CN201880010738.2A| CN110312682A|2017-01-06|2018-01-08|The method for preparing core shell hybrid material|