Vapor Deposition of Silicon-Containing Microstructured Polymer Films onto Silicone Oil Substrates

Abstract

In this study, a silicon-containing cross-linked polymer, poly­(1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane-co-ethylene glycol diacrylate) (p­(V4D4-co-EGDA)), was deposited onto high-viscosity silicone oil using initiated chemical vapor deposition (iCVD). The ratio of the feed flow rate of V4D4 to EGDA was systematically studied, and the chemical composition and morphology of the top and bottom surfaces of the films were analyzed. The films were microstructured, and the porosity and thickness of the films increased with increasing V4D4 content. The top of the film was composed of densely packed and loosely packed microstructured regions. X-ray photoelectron spectroscopy on the top and bottom surfaces of the films showed a heterogeneous chemical composition along the thickness of the film, with higher silicon content on the top surface compared to that on the bottom surface. To the best of our knowledge, this is the first study of iCVD deposition of a silicon-containing polymer film onto silicone oil. The results of this study can be used for the synthesis of polymer precursor films for the fabrication, via pyrolysis, of silicon-based inorganic membranes for use in hydrogen production using silicone oil to prevent infiltration of monomer into the underneath membrane support structure during vapor deposition.

Vapor-Deposited Polymer Films and Structure: Methods and Applications

“…Increasing the V4D4 content in the copolymer increased the porosity and microstructure regions. 50 Matsumoto's group provided a technique for producing porous polyurea (PU) via vacuum deposition polymerization with the ionic liquid (IL) of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide ([Emim][TFSA]). A porous PU film was copolymerized by depositing 4,4′-methylenebis(2chlorophenyl isocyanate) (MBCI) and 2,7-diaminofluorene (DAF) monomer molecules on the IL-coated substrate.…”