Welchert Nicholas A, Nguyen Bryan, Tsotsis Theodore T, Gupta Malancha
Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, 925 Bloom Walk, Los Angeles, California 90089, United States.
Langmuir. 2021 Nov 30;37(47):13859-13866. doi: 10.1021/acs.langmuir.1c02286. Epub 2021 Nov 18.
In this study, a silicon-containing cross-linked polymer, poly(1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane--ethylene glycol diacrylate) (p(V4D4--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.
在本研究中，使用引发化学气相沉积（iCVD）将一种含硅交联聚合物聚（1,3,5,7 - 四乙烯基 - 1,3,5,7 - 四甲基环四硅氧烷 - 乙二醇二丙烯酸酯）（p(V4D4 - EGDA)）沉积在高粘度硅油上。系统研究了V4D4与EGDA进料流速的比例，并分析了薄膜顶面和底面的化学成分及形态。薄膜具有微结构，且薄膜的孔隙率和厚度随V4D4含量的增加而增大。薄膜顶部由密集堆积和松散堆积的微结构区域组成。对薄膜顶面和底面进行的X射线光电子能谱分析表明，沿薄膜厚度方向化学成分不均匀，顶面的硅含量高于底面。据我们所知，这是首次关于将含硅聚合物薄膜通过iCVD沉积在硅油上的研究。本研究结果可用于合成聚合物前驱体薄膜，通过热解制备用于氢气生产的硅基无机膜，在气相沉积过程中使用硅油防止单体渗透到下方的膜支撑结构中。
