US 12,351,696 B2
Copolymer-silica hybrid aerogels and methods for the preparation thereof
Jianping Lu, Ottawa (CA); Zhiyi Zhang, Ottawa (CA); and Ye Tao, Ottawa (CA)
Assigned to National Research Council of Canada, Ottawa (CA)
Appl. No. 17/608,210
Filed by National Research Council of Canada, Ottawa (CA)
PCT Filed May 1, 2020, PCT No. PCT/CA2020/050581
§ 371(c)(1), (2) Date Nov. 2, 2021,
PCT Pub. No. WO2020/220138, PCT Pub. Date Nov. 5, 2020.
Claims priority of provisional application 63/010,865, filed on Apr. 16, 2020.
Claims priority of provisional application 62/841,897, filed on May 2, 2019.
Prior Publication US 2022/0204718 A1, Jun. 30, 2022
Int. Cl. C08J 9/28 (2006.01); C08J 9/00 (2006.01)
CPC C08J 9/28 (2013.01) [C08J 9/0061 (2013.01); C08J 9/0085 (2013.01); C08J 2201/0502 (2013.01); C08J 2205/026 (2013.01); C08J 2351/10 (2013.01); C08J 2401/02 (2013.01)] 12 Claims
 
1. 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:

OG Complex Work Unit Chemistry
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):

OG Complex Work Unit Chemistry
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.