Patent ID: 11944942
Assignee: NANJING TECH UNIVERSITY
Field: Chemical engineering (Chemistry)
Classification: CPC B  C  Y | IPC B  C

Claim 0:
1. A polyether block polyamide-polydimethylsiloxane composite membrane for gas separation, comprising: a support layer, an intermediate layer, and a selective layer, wherein the intermediate layer comprises a hydroxyl-terminated polydimethylsiloxane and a polydimethylsiloxane block polyethylene oxide, and the selective layer is made of a polyether block polyamide;
the hydroxyl-terminated polydimethylsiloxane and the polydimethylsiloxane block polyethylene oxide in the intermediate layer are crosslinked, and a crosslinking agent used in crosslinking of the hydroxyl-terminated polydimethylsiloxane and the polydimethylsiloxane block polyethylene oxide is tetraethyl orthosilicate;
the hydroxyl-terminated polydimethylsiloxane has a molecular weight of 20,000 to 200,000; the polydimethylsiloxane block polyethylene oxide has a molecular weight of 2,000 to 20,000; and
a preparation method of the polyether block polyamide-polydimethylsiloxane composite membrane for gas separation comprises the following steps:
step 1: thoroughly mixing the hydroxyl-terminated polydimethylsiloxane, the crosslinking agent, a catalyst, the polydimethylsiloxane block polyethylene oxide, and a first solvent to obtain an intermediate layer casting solution, coating the intermediate layer casting solution on a surface of the support layer, and performing a heat treatment; and
step 2: dissolving the polyether block polyamide in a second solvent, coating a resulting casting solution on a surface of the intermediate layer obtained in the step 1, and performing a heat treatment to obtain the polyether block polyamide-polydimethylsiloxane composite membrane for gas separation,
wherein a membrane obtained in the step 1 undergoes a plasma treatment for 1 s to 20 s at a current of 0.1 A to 5 A and a voltage of 20 V to 150 V.