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AssigneesCentre National De La Recherche Scientifique, Universite Claude Bernard I
InventorsFrédéric Chaput, Stéphane Parola, César Lopes, Denis Chateau, Cédric Desroches
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The invention concerns a preparation process of a hybrid organic-inorganic material including the following successive steps: a) preparation of a neutral organosilicon sol in at least one organic solvent, b) incorporation of a doping agent into the neutral organosiliconsol, and production of a doped sol, c) incorporation into the doped sol, of an accelerating agent in order to activate the subsequent gelation of the sol, d) condensation of the sol in order to obtain a crosslinked gel, e) drying of the gel and production of a stable doped gel. and the material obtainable by such a method.
1- Preparation process of a hybrid organic-inorganic material including the following successive steps:
2- Preparation process according to claim 1 characterized in that the gelation of the sol during step d) does not exceed more than one hour.
3- Preparation process according to claim 1 characterized in that the condensation rate of the sol obtained in step a) is equal to or greater than 0.65 and advantageously between 0.75 and 0.85 or between 0.85 and 0.95.
4- Preparation process according to claim 1 characterized in that the organo-silicon sol obtained in step a) to which the doping agent is added has a solid content (wt %) higher than 20%.
5- Preparation process according to claim 1 characterized in that the doped sol is stable and homogeneous, without precipitation of the doping agent.
6- Preparation process according to claim 1 characterized in that the organic solvent is selected so that the doped sol would be stable and homogeneous, without precipitation of the doping agent in the conditions of temperature and pressure selected for the implementation of the process.
7- Preparation process according to claim 1 characterized in that the organic solvent is selected among ketones such as acetone or 2-butanone, tetrahydrofuran, chloroform, dichloromethane, amides such as DMF and their mixtures.
8- Preparation process according to claim 1 characterized in that the doping agent is soluble in the organic solvent.
9- Preparation process according to claim 1 characterized in that the doping agent is selected among organic, organometallic or inorganic species that confer optical, mechanical, catalytic or magnetic properties to the material, such as photochromic agents and optical power limiting agents.
10- Preparation process according to claim 1 characterized in that the doping agent is selected among pyrromethene 597, 1,4,8,11,15,18,22,25-octabutoxyphtalocyanine, 2,11,20,29-tetra-tert-butyl-2,3-naphtalocyanine, platinum (II) complexes such as acetylides, naphtalocianines, lanthanide complexes, such as europium complexes, metal or metallic oxide nanoparticles.
11- Preparation process according to claim 1 characterized in that the accelerating agent is selected among 2-(trimethoxysilyl)ethyl-2-pyridine, trimethoxysilylpropyldiethylenetriamine, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropylmethyl-diethoxysilane, 3-aminopropyltriethoxysilane (APTES), 3-isocyanatopropyltriethoxysilane, 3-thiocyanatopropyltriethoxysilane, aminophenyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, 3-(2-imidazolin-1-yl)propyltriethoxysilane, diethylamine, triethylamine, diethanolamine, monoethanolamine, dodecylamine, aminopropyltrimethoxysilane (APTMS), N-methylAPTMS, N,N-dimethylAPTMS and N-methylpyrrolidone.
12- Preparation process according to claim 1 characterized in that the neutral organo-silicon sol used in step b) is deprived of water, as determined by the absence of peaks corresponding to water by NMR1H.
13- Preparation process according to claim 1 characterized in that the gelation is carried at a temperature belonging to the range 20-100° C., preferably at a temperature in the range 20-50° C., for instance at room temperature (20-25° C.) or at a temperature slightly above room temperature(30-50° C.).
14- Preparation process according to claim 1 characterized in that the gelation is carried at a temperature below the temperature used during the subsequent drying step.
15- Preparation process according to claim 1 characterized in that the solvent(s) which is(are) present (especially the organic solvent of the sol) is(are) removed after the gelling step d).
16- Preparation process according to claim 1 characterized in that the concentration of the accelerating agent incorporated in step c) will be in the range 0.02 mM-1 mM.
17- Preparation process according to claim 1 characterized in that the doped sol has a high concentration of doping agent, defined as equal or higher than 0.7 mole/L (of sol).
18- Hybrid organic-inorganic material constituted by a silica network in which at least one doping agent, representing at least 30%, and preferably at least 40% in mass of the material, is included.
19- Hybrid organic-inorganic material according to claim 18 characterized in that the doping agent is selected among photochromic agents and optical power limiting agents.
20- Hybrid organic-inorganic material according to claim 18 characterized in that the doping agent is a platinum (II) complexe such as an acetylide.
21- Hybrid organic-inorganic material constituted by a silica network in which at least one doping agent which is quasi-insoluble is included, the final concentration of the doping agent in the matrix being much higher than the saturation concentration in the matrix prepared by a conventional process.
22- Hybrid organic-inorganic material according to claim 18 characterized in that the material is a massive monolith material, such as a xerogel or an aerogel, or a thin film.
23- Hybrid organic-inorganic material according to claim 18 characterized in that the doping agent is uniformly distributed in the material.
24- Hybrid organic-inorganic material constituted by a silica network in which at least one doping agent, representing at least 30%, and preferably at least 40% in mass of the material, is included and is obtainable by the process according to claim 1.