Rapid preparation of hydrogen barrier films by a novel ultrasonic atomization-assisted layer-by-layer self-assembly method

Abstract

Layer-by-layer (LBL) self-assembled films of polyethyleneimine (PEI)/graphene oxide (GO) based on non-covalent force exhibit superior hydrogen barrier properties. Nevertheless, immersing the film in the self-assembly solution brings the problem of cross-contamination during the experiment. The deionized water rinsing step not only consumes time, but also increases the tediousness of membrane production and generates plenty of waste liquid. Herein, a PEI/GO hydrogen barrier film was prepared by ultrasonic atomization-assisted technology. Relying on stable and continuous spraying process and tiny droplets to achieve a unified and ordered surface of the film. The spray time, the dispersion concentration of GO, the pH of PEI solution, and the number of assembled layers were investigated in depth. The study shows that the hydrogen barrier film with excellent performance can be prepared by the atomization-assisted method. When the concentration of GO was 0.9 mg ml−1, the spray time of PEI and GO were 8 s and 20 s, the pH of PEI and GO were 10 and 4, respectively, the hydrogen transmission rate of 25-layer PEI/GO composite films was 21.343 cm3 m−2·day−1·0.1 MPa−1, which was 92.38% lower than that of polyethylene terephthalate (PET) substrates film. Furthermore, this method has high raw material utilization and is easy to scale.