title: Transparent and Dense Ladder-Like Alkylene-Bridged Polymethylsiloxane Coating with Enhanced Water Vapor Barrier Property.
abstract: Organic-inorganic hybrid composites have been well-studied as water vapor barrier materials for their long diffusion length of water vapor in coatings which can be realized by improving the aspect ratio of inorganic components and regularity of nanostructure in coatings. In this paper, dense organic-inorganic hybrid coating based on ladder-like alkylene-bridged polymethylsiloxane (ABPMS) was successfully fabricated through the hydrosilylation reaction between polymethylhydrosiloxane and diene (1,5-hexadiene or 1,7-octadiene) in toluene under Pt/C catalysis. Its ladder-like structure was verified by 29Si magic angle spinning (MAS) NMR, 13C MAS NMR, and in-plane and out-of-plane glance-incident X-ray diffraction (GIXRD) techniques. Its corresponding coating showed excellent water vapor barrier ability for a typical water-soluble crystal, potassium dihydrogen phosphate (KDP). When treated in 50% relative humidity (RH) condition at 25 °C for 8 months, the ABPMS coating with 100 nm thickness displayed a very low transmittance loss of 1.6% compared with the high transmittance loss of 10% for uncoated KDP. Moreover, the ABPMS coating showed good ultraviolet radiation resistance, thermal stability, low mechanical property, and excellent compatibility with hydrophobic antireflective (AR) coatings.
authors.affiliation: Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences , Taiyuan, Shanxi 030001, China.|University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Ce
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences , Taiyuan, Shanxi 030001, China.|University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences , Taiyuan, Shanxi 030001, China.|University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Xinmin
authors.initials: X
authors.lastname: Cui
authors.affiliation: Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences , Taiyuan, Shanxi 030001, China.|University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Jinghua
authors.initials: J
authors.lastname: Sun
authors.affiliation: Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences , Xi'an, Shaanxi 710119, China.
authors.forename: Ruimin
authors.initials: R
authors.lastname: Ding
authors.affiliation: Chengdu Fine Optical Engineering Research Center , Chengdu, Sichuan 610041, China.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences , Xi'an, Shaanxi 710119, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Xu
keywords: alkylene-bridged polymethylsiloxane; dense coating; hydrosilylation; ladder-like polymer; water vapor barrier coating