Polyimide-based organic solvent nanofiltration membrane with crosslinked active layer and preparation method thereof

The present invention relates to a technology for producing a polyimide-based separation membrane in the form of a flat membrane having an active layer with a cross-linked structure by polyethyleneimine and glutaraldehyde, and applying the same as an organic solvent nanofiltration membrane. According to the present invention, a polyimide-based organic solvent nanofiltration membrane having an active layer with a cross-linked structure in the form of a flat membrane can be provided which has a high permeability of ethyl alcohol and in which a removal rate of a specific solute (molecular weight of about 500 g/mol) from a solution is significantly improved compared to a conventional polyimide nanofiltration membrane without a cross-linked structure and a polyimide nanofiltration membrane having a cross-linked structure by a diamine compound, and a producing method thereof. The producing method of the polyimide-based organic solvent nanofiltration membrane with a cross-linked structure in the form of a flat membrane is provided which comprises the steps of: obtaining a dope solution; forming an asymmetrical separation membrane; and performing a cross-linking reaction. 본 발명은 폴리에틸렌이민 및 글루타알데히드에 의해 가교구조의 활성층을 갖는 평막 형태의 폴리이미드계 분리막을 제조함으로써, 이를 유기용매 나노여과막으로 응용하는 기술에 관한 것이다. 본 발명에 의하면, 에틸알코올의 투과도가 높으면서도, 용액에서 특정 용질(분자량 약 500g/mol)의 제거율이 종래 가교구조를 갖지 않는 폴리이미드 나노여과막 및 디아민계 화합물에 의하여 가교구조를 갖는 폴리이미드 나노여과막에 비하여도 현저히 향상된 평막 형태의 가교구조의 활성층을 갖는 폴리이미드계 유기용매 나노여과막 및 그 제조방법을 제공할 수 있다.