▎ 摘　　要

NOVELTY - A superhydrophilic graphene oxide composite film comprises graphene oxide nanosheet and phytic acid-iron ion complex as crosslinking agent. The phytic acid molecule as crosslinking agent is inserted into the graphene oxide nanosheet layer to obtain the graphene oxide composite film crosslinked with phytic acid. The film is immersed in ferric chloride solution to chelate the phytic acid-iron ion graphene oxide composite film with superhydrophilic surface based on the function of chelate acid and iron ion. USE - Superhydrophilic graphene oxide composite film is used for osmotic evaporation dehydration of butanol-water system (claimed). ADVANTAGE - The composite film has strong controllability, high selectivity, and excellent high-temperature operational stability, can be prepared by a simple method. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) preparation of the composite film, which involves dissolving phytic acid in deionized water to obtain a phytic acid dispersion, dissolving graphene oxide nanosheets in the phytic acid dispersion to obtain a mixed solution, stirring the mixed solution for 1 hour at 70 degrees C, ultrasonically dispersing, filtering the mixed solution at 0.48 MPa using a hydrophilic PTFE film of 0.22 mu m aperture, heating in an oven at 80 degrees C for 2 hours to obtain a phytic acid crosslinked graphene oxide composite film, soaking the composite film in 0.4-0.6 mmol/L, preferably 0.4 mmol/L or 0.6 mmol/L ferric chloride solution for 20 minutes, taking out the film, washing with deionized water, and drying at room temperature. The mass ratio of phytic acid and graphene oxide nanosheet is (0.1-1):1, preferably 0.5:1; and (2) use of the composite film for osmotic evaporation dehydration of butanol-water system at 80 degrees C, using 90 %mass butanol-water solution, osmotic flux of 9.58-10.57 kg/m2.hour, and separation factor of 510-1059.