Formation of Porous Polymer Coatings on Complex Substrates Using Vapor Phase Precursors

Abstract

In this work, porous poly(methacrylic acid) (PMAA) coatings are formed on complex substrates using vapor phase precursors. The porous coatings are created by partially polymerizing solid monomer deposited onto the substrate. The conformality of the porous PMAA coatings is studied on the external and internal surfaces of cylindrical substrates. Flow effects lead to thickness variations in the θ-direction while thermal gradients and monomer depletion effects lead to thickness variations in the z-direction. These variations can be reduced by modifying the flow rate of the monomer vapor, by reducing the radiative heat on the substrate, or by increasing the dimension size of the substrate. This work shows that vapor phase processing methods can be a viable alternative to solution phase methods and the observed trends can be utilized in a range of vapor phase technologies to optimize porous coatings for use in tissue engineering, sensors, and separations.