Polyimide/silicon dioxide composite nanofiber film and preparation thereof

The invention discloses a polyimide composite nanofiber film with the surface coated with silicon dioxide nano particles or silicon dioxide nanolayers and a preparation method thereof, and belongs to the field of high polymer materials. Polyamide acid precursor nanofibers with the surface containing silicon sources are prepared firstly by adopting electrostatic spinning, precursor nanofibers with parts imidized and the surface coated with a silicon source are manufactured by controlling heat processing temperature, and then the polyimide composite nanofiber film with the surface coated with the silicon dioxide nano particles or the silicon dioxide nanolayers can be obtained through acidification and hydrolyzation processing and high temperature thermal cyclization processing. Compared with an original polyimide fiber film, the polyimide nanofiber film with the surface coated with nanosilicon dioxide has higher temperature resistance performance and dimensional stability to heating, specially, the wettability is outstanding, the void content is high, the mechanical property is excellent, and the polyimide/silicon dioxide composite nanofiber film and the preparation thereof have wide application prospects in the field of novel lithium battery diaphragms which have a request for high temperature resistance and high safety.