Structural analysis of hybrid titania-based mesostructured composites

被引：0

作者：

Boettcher, Shannon W. ^{[1
]}

Bartl, Michael H. ^{[1
]}

Hu, Jerry G. ^{[1
]}

Stucky, Galen D. ^{[1
]}

机构：

[1] Department of Chemistry and Biochemistry, California NanoSystems Institute (CNSI), University of California, Santa Barbara, CA 93106, United States

来源：

Journal of the American Chemical Society | 2005年 / 127卷 / 27期

关键词：

Copolymers - Correlation methods - Infrared spectroscopy - Nuclear magnetic resonance - Optical properties - Polyethylene oxides - Polypropylene oxides - Raman spectroscopy - Structural analysis - Titanium;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

High-optical-quality titania-based mesostructured films with cubic or 2D-hexagonal symmetry were fabricated by combining trifluoroacetate (TFA)-modified titanium precursors with amphiphilic triblock poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) copolymers. The distribution, dynamics, and local environments of the TFA-modified titania, PEO, and PPO components of the hybrid were investigated. IR/Raman spectroscopy, in situ small-angle X-ray scattering, and transmission electron microscopy studies indicate that TFA coordinates the titanium center and forms a stable complex that is subsequently organized by the block copolymer species into ordered mesostructures. Solid-state NMR 19F&rarr1H cross-polarization, 13C{1H} two-dimensional heteronuclear correlation, and 1H relaxation techniques were used to determine that PEO is predominantly incorporated within the TFA-modified titania, and that PPO environments encompass both microphase separated regions and interfacial regions composed of mixed PPO and TFA-modified titania. NMR 19F multiple-quantum spin counting measurements suggest that -CF3 groups of the trifluoroacetate ligands do not form clusters but instead randomly distribute within the inorganic component of the hybrid. © 2005 American Chemical Society.

引用

页码：9721 / 9730