Functionalized Nanoporous Gyroid SiO2 with Double Stimuli-Responsive Properties as Environment-Selective Delivery Systems

李慧君(Hui-Chun Lee)

指導教授 ： 何榮銘

國立清華大學/工學院/化學工程學系/碩士(2013年)

https://doi.org/10.6843/NTHU.2013.00355

摘要

Functionalized nanoporous materials with high porosity and high specific surface area have become promising materials for appealing applications. Gyroid phase with ordered, bi-continuous networks in 3D space is one of the most appealing morphologies for practical applications due to its high specific interfacial surface area. In this study, we aim to fabricate nanoporous gyroid SiO2 materials from templated sol-gel reaction using degradable block copolymer with gyroid-forming nanostructure as a template, and then to functionalize the nanoporous materials using “smart” polymer, poly(2-dimethylaminoethyl methacrylate) (PDMAEMA), brushes via “grafting from” method to give double stimuli-responsive properties. By taking advantage of the environmental stimuli, both thermal and pH, the pore features can be well defined by stretching and re-coiling of the grafted PDMAEMA brushes because of their adjustable chain conformation with reversible character. The grafting PDMAEMA on the inner wall of the nanoporous materials is evidenced by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The responsive properties with respect to environmental stimuli can be successfully traced by temperature-resolved small angle X-ray scattering (SAXS) in aqueous environment. Owing to the high specific surface area, 3D pore network, biocompatibility and environmental response, the functionalized nanoporous gyroid SiO2 are further demonstrated as stimuli-responsive controlled release system. As a result, the nanoporous SiO2 with tunable pore size can be fabricated to give promising properties for various applications, such as environment-selective delivery systems, bio-mimetic on/off gates, and specific environmental detectors.

關鍵字

BCP ； nanoporous SiO2 ； gyroid ； stimuli-responsive ； PDMAEMA

並列摘要

Functionalized nanoporous materials with high porosity and high specific surface area have become promising materials for appealing applications. Gyroid phase with ordered, bi-continuous networks in 3D space is one of the most appealing morphologies for practical applications due to its high specific interfacial surface area. In this study, we aim to fabricate nanoporous gyroid SiO2 materials from templated sol-gel reaction using degradable block copolymer with gyroid-forming nanostructure as a template, and then to functionalize the nanoporous materials using “smart” polymer, poly(2-dimethylaminoethyl methacrylate) (PDMAEMA), brushes via “grafting from” method to give double stimuli-responsive properties. By taking advantage of the environmental stimuli, both thermal and pH, the pore features can be well defined by stretching and re-coiling of the grafted PDMAEMA brushes because of their adjustable chain conformation with reversible character. The grafting PDMAEMA on the inner wall of the nanoporous materials is evidenced by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The responsive properties with respect to environmental stimuli can be successfully traced by temperature-resolved small angle X-ray scattering (SAXS) in aqueous environment. Owing to the high specific surface area, 3D pore network, biocompatibility and environmental response, the functionalized nanoporous gyroid SiO2 are further demonstrated as stimuli-responsive controlled release system. As a result, the nanoporous SiO2 with tunable pore size can be fabricated to give promising properties for various applications, such as environment-selective delivery systems, bio-mimetic on/off gates, and specific environmental detectors.

並列關鍵字

BCP ； nanoporous SiO2 ； gyroid ； stimuli-responsive ； PDMAEMA

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