Copolymer-silica hybrid aerogels and methods for the preparation thereof
AssigneeNational Research Council of Canada
InventorsJianping Lu, Zhiyi Zhang, Ye Tao
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Abstract
The present application relates to copolymer-silica hybrid aerogels as well as methods for the preparation thereof. The methods comprise hydrolyzing a silica precursor in an organic solvent to obtain a partially polymerized silica wet gel, reacting the partially polymerized silica wet gel with a copolymer of Formula (II) to obtain a copolymer-silica hybrid wet gel, reacting the copolymer-silica hybrid wet gel with a surface passivation agent and removing solvent from the copolymer-silica hybrid wet gel to obtain the copolymer-silica hybrid aerogel. The mechanical properties of the copolymer-silica hybrid aerogels can be further improved by blending cellulose nanofibrils into the hybrid aerogels. (II)
Claims12
A method of preparing a copolymer-silica-nanocellulose hybrid aerogel, the method comprising:
- (a) hydrolyzing and condensing a silica precursor of Formula (I) in the presence of cellulose nanofibrils:
- wherein R1a, R1b, R1c and R1d are each independently a hydrolysable group, in an organic solvent to obtain a partially polymerized silica wet gel;
- (b) reacting the partially polymerized silica wet gel with a copolymer of Formula (II):
- wherein
- R2 is H or methyl;
- R3a, R3b and R3c are each independently a hydrolysable group;
- R4 is chosen from a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group and a substituted or unsubstituted heteroaryl group;
- A is C2-10alkylene;
- and
- x is a molar fraction of from 0.1 to 0.95,
- to obtain a copolymer-silica-nanocellulose hybrid wet gel;
- (c) reacting the copolymer-silica-nanocellulose hybrid wet gel with a surface passivation agent;
- and
- (d) removing solvent from the copolymer-silica hybrid wet gel to obtain the copolymer-silica-nanocellulose hybrid aerogel.
Dependencies are inferred from the claim text.