Efficient preparation of hydrogen barrier films by ultrasonic‐assisted layer‐by‐layer assembly

Abstract Graphene oxide (GO) can be self‐assembled with various polymer materials layer by layer to prepare composite materials with excellent barrier properties. However, the process is cumbersome and time‐consuming. In this article, GO/polyethyleneimine(PEI) hydrogen barrier films were successfully prepared by ultrasonic‐assisted layer‐by‐layer self‐assembly technology. Results show that the ultrasonic‐assisted method not only reduced the immersion time from several minutes to 10 s, but also increased the density of the material packing to reduce the channels through which hydrogen molecules can diffuse while improving the horizontal orientation of the GO sheet to prolong the diffusion paths of gas molecules. Finally, the hydrogen transmission rate of 20‐bilayer films assembled under ultrasonic conditions is equivalent to that of 30‐bilayer films assembled without ultrasonic conditions, which greatly shortens the film‐making period. Therefore, the ultrasonic‐assisted method has a good prospect in the preparation of gas barrier films.