Amphiphilic silsesquioxane nanoparticles by hydrolytic condensation of Y-shaped triethoxysilanes having hydroxyl and fluoroalkyl groups: Synthesis, self-assembly, and surface properties

Publication date: 10 February 2017
Source:Polymer, Volume 110
Author(s): Ryo Koizumi, Tetsuya Kimura, Kazuhiro Nakabayashi, Hideharu Mori
Two Y-shaped molecules combining two dissimilar (hydrophilic and hydrophobic) units with a reactive triethoxysilane moiety were synthesized by Michael addition reaction of (aminopropyl)triethoxysilane with 2-hydroxyethyl acrylate (HEA), followed by the addition of 2,2,2-trifluoroethyl acrylate (TFEA) or 1H,1H,5H-octafluoropentyl acrylate (OFPA). Hydrolytic condensations of the Y-shaped triethoxysilane precursors proceeded as homogeneous systems in acetone in presence of the acidic catalyst to afford amphiphilic silsesquioxane nanoparticles (SQ-NPs) having hydroxyl and fluoroalkyl groups (HEA/TFEA-SQ and HEA/OFPA-SQ). Scanning force microscope (SFM), X-ray diffraction (XRD), and size-exclusion chromatography (SEC) measurements indicated the formation of nanoparticles (average particle diameter is about 2.0 nm) with reasonable molecular weights and low dispersities (Mn = 5100-5400, Mw/Mn = 1.22–1.36) without aggregation. Characteristic assembled structures and surface properties of the amphiphilic SQ-NPs in different solvents were also evaluated. Flexible self-standing films were obtained from the amphiphilic SQ-NPs without any additional compounds, which are due to intermolecular hydrogen bondings.

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