Inorganic layered polymeric membranes: Highly-ordered porous ceramics for surface engineering of polymeric membranes

The mesoporous ceramic membranes showed great potential due to their high stability and resistance to harsh environments. However, the high weight and considerable production costs of ceramic membranes reduced their application. For using both the flexible properties of polymers and the high chemical resistance of ceramic, the coating or growing of a thin ceramic layer on the polymeric support is a well-built strategy. The growth of thin barrier layers on flexible polymer substrates by different techniques produced high-performance membranes. Ceramic materials can be categorized according to their structure, composition, and method of production. Based on the structure and characteristics of the membranes, this article discusses the thin coating of various forms of ceramics onto polymeric membranes. This review highlights the state-of-the-art insights into the fabrication of ultrathin ceramic selective layers and their applications as separation membranes. Different techniques such as contra diffusion, atomic layer deposition, chemical vapor deposition, pressure-assisted self-assembly, gel-vapor deposition, in-situ crystal formation, and facile vacuum filtration process have been reviewed. A brief description of several ceramic material types and surface engineering techniques is also included. Thus, this review, which combines several disciplines, offers academics interested in the subject a summary of current development and research as well as a roadmap for future paths and concluding remarks.