公开(公告)号：US11766640B2

公开(公告)日：2023-09-26

申请号：US18001092

申请日：2022-03-23

Applicant: NANJING TECH UNIVERSITY

Inventor： Yong Wang ,  Dinglei Zhong ,  Jiemei Zhou

IPC: B01D67/00 ,  B01D71/52 ,  B01D69/08 ,  B01D71/68 ,  B01D71/80 ,  D01D5/24 ,  D01F1/08

CPC classification number: B01D67/0027 ,  B01D67/002 ,  B01D69/08 ,  B01D71/5211 ,  B01D71/68 ,  B01D71/80 ,  D01D5/24 ,  D01F1/08

Abstract: The disclosure provides a method for preparing a hollow fiber membrane by melt spinning-stretching and selective swelling, including: preparing a nascent hollow fiber by melt spinning in an inert gas protective atmosphere by using an amphiphilic block copolymer as a film forming material, and stretching the nascent hollow fiber in the cooling process, a stretch rate being controlled at 200-540 mm/min, and a stretch ratio being controlled at 150-600%; immersing the obtained hollow fiber in a swelling solvent, and treating the hollow fiber in a water bath at 65° C. for 1 h; and then transferring the hollow fiber into a long-chain alkane solvent, treating the hollow fiber at the same temperature for 1-12 h, and after the completion of the treatment, immediately taking out the hollow fiber and drying the hollow fiber to obtain the hollow fiber membrane with a bicontinuous porous structure. By combining the melt spinning-stretching and the selective swelling, the method of the disclosure can synchronously and continuously improve the permeability and selectivity of the hollow fiber membrane. The treatment in the long-chain alkane solvent can make the polar chain excessively enriched on the surface of the membrane migrate inward, thereby improving the performance of the hollow fiber membrane.

公开(公告)号：US11504672B2

公开(公告)日：2022-11-22

申请号：US17596985

申请日：2020-06-19

Applicant: NANJING TECH UNIVERSITY

Inventor： Yong Wang ,  Yanjie Wang ,  Jiemei Zhou

IPC: B01D67/00 ,  B01D71/80

Abstract: The present invention provides a room-temperature selective swelling method of pore-forming used for preparing separation membranes, comprising: treating a dense membrane of an amphiphilic block copolymer by a composite swelling agent at 15-30° C. for 1 min-24 h, removing the residual solvent, then leaving the membrane at room temperature to dry, so as to obtain an amphiphilic block copolymer separation membrane with a bi-continuous porous structure, wherein the composite swelling agent is composed of 60-96% of a first swelling agent and 4-40% of a second swelling agent, the first swelling agent is an alcohol solvent, the second swelling agent is selected from any one or a mixture of two or more of toluene, styrene, tetrahydrofuran, 1,4-dioxane and so on. In the method of the invention, selective swelling can be achieved at room temperature, abating the energy consumption in membrane-forming process. The method has universality and can be widely used in the pore-forming process of various amphiphilic block copolymers. The swelling level and morphology can be controlled by adjusting the composition of the solvent in the swelling agent and the second swelling agent content in the swelling agent.