Abstract

The characterization of the organization of matter at different length scales is one of the main features in the field of mesostructured materials. Here, SAXS, solid-state multinuclear (²⁹Si, ¹H) MAS NMR spectra and one-dimensional ¹H spin diffusion MAS NMR experiments have been used to characterize the structure and the copolymer−siloxane interfaces of monolithic hybrid organic−inorganic membranes. The membranes were prepared by cohydrolysis of organically modified alkoxysilanes (methyltriethoxysilane (MTES) and dimethyldimethoxysilane (DMDES)) with tetraethylorthosilicate (TEOS) and using a triblock copolymer PEO-PPO-PEO as templating agent. After careful drying, a cubic Im3_m mesostructure is obtained. Variations in the composition of the hybrid membrane have been found to affect the adsorption of water at the copolymer−siloxane interface as well as the spatial distribution of propylene oxide (PO), ethylene oxide (EO), and siloxane domains in the final mesostructures. In that sense, the modulation of the polarity of the interfaces by simply adjusting the nature and quantity of organically modified alkoxides seems to be a promising way for the control of the final mesostructures.

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