title: The architecture of the adsorbed layer at the substrate interface determines the glass transition of supported ultrathin polystyrene films.
abstract: To elucidate the mechanism underlying the effect of polymer/solid interfacial interactions on the dynamics of thin polymer films, the glass transition of thin end-functionalized polystyrene films supported on SiO2-Si, such as proton-terminated PS (PS-H), α,ω-dicarboxy-terminated PS (PS-COOH), and α,ω-dihydroxyl-terminated PS (PS-OH), was investigated. All the PS films exhibited a substantial depression in Tgwith decreasing film thickness, while the extent of such depression was strongly dependent on the chemical structure of the end groups and molecular weights. It was found that T - T of the various PS films increased linearly with increasing hads/Rg, in which hadsis the thickness of the interfacial adsorbed layer and Rgis the radius of gyration of PS. The hads/Rgis a direct reflection of the macromolecular chain conformation within the adsorbed layer which was affected by its end groups and molecular weights. These findings are in line with the work of Napolitano, and present direct experimental evidence.
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China. wxinping@yahoo.com wxinping@zstu.edu.cn.
authors.forename: Shuzheng
authors.initials: S
authors.lastname: Sun
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China. wxinping@yahoo.com wxinping@zstu.edu.cn.
authors.forename: Hao
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China. wxinping@yahoo.com wxinping@zstu.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Han
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China. wxinping@yahoo.com wxinping@zstu.edu.cn.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China. wxinping@yahoo.com wxinping@zstu.edu.cn.
authors.forename: Biao
authors.initials: B
authors.lastname: Zuo
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China. wxinping@yahoo.com wxinping@zstu.edu.cn.
authors.forename: Xinping
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Education Ministry, Zhejiang Sci-Tech University, Hangzhou 310018, China. wxinping@yahoo.com wxinping@zstu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang