Preparation of mesoporous and macroporous silica gel
The present application discloses a process for preparing silica particles, said process comprising the step of mixing (I) an aqueous phase and (II) an oily phase comprising pre-polymerized tetraalkoxy orthosilicate, one or more alcohols, and optionally one or more polyalkylene glycols, wherein said aqueous phase comprises, in an aqueous solvent, one or more C 6-30 -alkyl modified polysaccharides, and optionally one or more polyalkylene glycols.
1. A process for preparing silica particles, said process comprising the steps of:
mixing
(i) an aqueous phase and
(ii) an oily phase comprising pre-polymerized tetraalkoxy orthosilicate, one or more alcohols, and optionally one or more polyalkylene glycols;
adding one or more bases under stirring;
washing, heating, and drying the particles;
wherein said aqueous phase comprises, in an aqueous solvent, one or more C 6-30 -alkyl modified polysaccharides, and optionally one or more polyalkylene glycols.
2. The process according to claim 1 , wherein C 6-30 -alkyl modified polysaccharide is present in the aqueous phase in an amount of 0.01-10%(w/w).
3. The process according to claim 1 , wherein (i) the aqueous phase and (ii) the oily phase are mixed in a weight ratio of from 10:1 to 1:2.5.
4. The process according to claim 1 , wherein the modified polysaccharide is selected from inulin C 8-24 -alkyl carbamates.
5. The process according to claim 1 , wherein the aqueous phase is essentially devoid of N,N-dimethyl formamide.
6. The process according to claim 1 , wherein the resulting silica particles are reacted with a silane of the formula HSiR 2 R*, wherein each of R independently is a C 1-4 -alkyl group, and wherein R* is a C 4-30 -alkyl group.