Self-assembled PVDF (polyvinylidene fluoride) composite membrane as well as preparation method and application thereof

The invention relates to a self-assembled PVDF (polyvinylidene fluoride) composite membrane as well as a preparation method and application thereof, and relates to the technical field of water treatment materials, the composite membrane comprises a PVDF grafted membrane with L-cysteine grafted on the surface and a polyethyleneimine layer grafted on the surface of the PVDF grafted membrane. The preparation method comprises the following steps: S1) providing a PVDF base membrane; s2) grafting on the PVDF base membrane by using an L-cysteine solution to form an L-cysteine layer, so as to obtain a PVDF grafted membrane; and S3) performing self-assembly grafting on the surface of the PVDF grafted membrane by using a polyethyleneimine solution to form a polyethyleneimine layer, thereby obtaining the PVDF composite membrane. The invention also provides an application of the self-assembled PVDF composite membrane obtained based on the preparation method. The self-assembled PVDF composite membrane optimizes the hydrop