Atomic Layer Deposition and Vapor Phase Infiltration

This chapter examines the use of two chemical vapor processing schemes – atomic layer deposition (ALD) and vapor phase infiltration (VPI) – as a means to introduce inorganic components to the surface and/or subsurface chemistry of polymers in a variety of modalities, including films, fibers, foams, and fabrics. It details the phenomenology of these processes and the applications of the resulting materials systems. Cotton and polyvinyl alcohol are prototypical polymers for receiving metal oxide ALD coatings. Polymers with purely hydrocarbon chemistries and other inert functional groups are fairly unreactive toward most precursor chemistries used for ALD. Unlike ALD, infiltration requires low to moderate reactivity between the vapor phase precursor and polymer in order to allow precursor transport past the polymer's surface. Experimental methods for studying the VPI processing thermodynamics and kinetics require tracking the amount of inorganic uptake with process time under various process conditions (temperature, partial pressure, etc.).