▎ 摘　　要

NOVELTY - Nano fiber film, comprises 68-85 wt.% polyvinylidene difluoride, 0.9-2.9 wt.% graphene and 14-29 wt.% polyvinyl pyrrolidone. USE - Used as nano fiber film. ADVANTAGE - The film enhances the hydrophilicity of polylactic acid; and can be reused after simple cleaning. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparation of nano fiber film, comprising (i) dissolving graphene in dimethylacetamide to obtain graphene solution, uniformly stirring and mixing at 60?; (ii) adding polyvinylidene difluoride into graphene solution to obtain solution and uniformly stirring; (iii) adding polyvinyl pyrrolidone to solution obtained in step (ii) to obtain solution and uniformly stirring; (iv) uniformly stirring and mixing the spinning solution obtained in step (iii) at 60 degrees C for static de-foaming; (v) placing spinning solution at 20 KV and pushing speed of 5 l/minute, where the distance between the needle and the roller is 17 cm and the roller speed is 280 revolutions/minute, controlling temperature at 25 degrees C with relative humidity of 25%; and (vi) soaking the film in solution obtained in step (v) in the de-ionized water for 24 hours, to be tested.