Atomic Layer Deposition for Polypropylene Film Engineering-A Review

Polypropylene (PP) polymers are used extensively as dielectric layers, packaging films, and separation membranes, etc. Structure, chemistry, and surface features of PP films dominate their performance and durability. Modification of PP films is carried out using atomic layer deposition (ALD) among other techniques to coat uniform layer of nanometer inorganic material on the surface and inside the pores of PP films to serve the purpose of target applications better. Controlling the reaction temperature, precursor pulsing time, and number of cycles during deposition predominate the thickness, morphology, and composition of the coated layer and hence the performance of PP films. Overall, the ALD technique has been proven to be advantageous in advancing PP film properties such as hydrophilicity, UV resistance, membrane separators, dielectric and mechanical strength, etc., primarily through the controllable formation of nanometer coating on PP films. This review discusses the recent advancements and prospective of ALD in the modification and functionalization of PP films for various applications to provide some insights and motivations to design high-performance novel PP films by well leveraging the ALD technique.