▎ 摘　　要

NOVELTY - Preparing poly(vinyl alcohol) (PVA) and graphene oxide composite nano-fiber film, comprises (i) preparing PVA and graphene oxide composite spinning solution; (ii) preparing small sheet oxide graphene by (a1) adding expandable natural graphite powder to concentrating sulfuric acid, adding fuming nitric acid, stirring, pouring into deionized water for dilution, filtering, washing, drying and subjecting to microwave expansion to obtain expanding graphite, (b1) adding expanding graphite into concentrating sulfuric acid, adding potassium persulfate and phosphorus pentoxide, stirring, pouring into water and diluting, cooling down, washing, filtering and drying, and (c1) adding pre-oxidized graphite with concentrating sulfuric acid, adding potassium permanganate and pouring it into deionized water for dilution, cooling, adding hydrogen peroxide, diluting, centrifuging and washing to obtain graphene oxide dispersion; (iii) mixing steps (i) and (ii) product; and (iv) electro-spinning. USE - The method is useful for preparing poly(vinyl alcohol) and graphene oxide composite nano-fiber film . ADVANTAGE - The method utilizing spinning solution spins the fiber film under high-pressure electrostatic through a micro-injection pump and has a small fiber diameter where the small holes have high tensile strength, better filtration than traditional non-woven filters and can effectively prevent the inhalation of particulate matter 2.5 (PM2.5). DETAILED DESCRIPTION - Preparing poly(vinyl alcohol) (PVA) and graphene oxide composite nano-fiber film, comprises (i) preparing PVA and graphene oxide composite spinning solution by (a) dissolving PVA in deionized water and adjusting the solution to acidic, (b) preparing surfactant solution by adding sodium dodecyl sulfate into the solution obtained, (c) adding sodium lauryl sulfate solution dropwise to the PVA solution and (d) reacting at high temperature for a certain period of time; (ii) preparing small sheet oxide graphene by (a1) adding a certain amount of expandable natural graphite powder to a certain amount of concentrating sulfuric acid, slowly adding a certain amount of fuming nitric acid, stirring in an ice bath, pouring into deionized water for dilution, filtering, washing with water, drying at a certain temperature, subjecting to microwave expansion under certain power for a certain time to obtain expanding graphite, (b1) adding the above expanding graphite into a certain amount of concentrating sulfuric acid, adding a certain amount of potassium persulfate and phosphorus pentoxide, stirring at a certain temperature, pouring into water and diluting, cooling down, washing, filtering and drying to obtain pre-oxidized graphite, and (c1) adding the pre-oxidized graphite with certain amount of concentrating sulfuric acid, adding a certain amount of potassium permanganate and pouring it into deionized water for dilution, cooling to room temperature, adding hydrogen peroxide, pouring into deionized water for diluting, allowing to stand, centrifuging and washing to obtain graphene oxide dispersion; (iii) mixing steps (i) and (ii) product and stirring for a period of time at a certain temperature; and (iv) electro-spinning the PVA and graphene oxide composite spinning solution into nano-fiber film.