Flexible membranes fabricated by initiated chemical vapor deposition for water treatment, battery, and drug delivery

With the development of advanced yet structurally complex systems, flexible membranes have attracted increasing attention. Initiated chemical vapor deposition (iCVD), an emerging, facile, scalable technique to deposit high-quality polymer thin films on arbitrary substrates, holds great promise in the fabrication of flexible membranes. iCVD features solvent-free, gentle deposition conditions that enable the processing of various solvent-susceptible, fragile, or delicate substrates. The mechanical flexibility, precisely controlled morphology, and abundant physiochemical property of iCVD polymer films enable the design and optimization of membrane characteristics for diverse applications. Herein, we provide a comprehensive review of the fabrication and ap-plications of iCVD flexible membranes. First, we introduce the deposition mechanism and parameters of iCVD. We then critically discuss the applications of iCVD membranes in water treatment, battery, and drug delivery, elaborating their processing-property-performance interrelationships. Finally, we discuss the scale-up and commercialization of iCVD, followed by the limitations and future directions in the field.