2:15 PM - 2:30 PM
△ [16p-Z17-4] pH-Responsive Ultrathin Nanoporous SiO2 Films for Selective Ion Permeation
Keywords:surface functionalization, polymer nanosheet, silsesquioxane
We report selective ion permeation using surface functionalized ultrathin nanoporous (NP) SiO2 films modified by an amine-containing silane coupling agent (3-aminopropyltriethoxysilane (APTES)). Atomic force microscopy and x-ray photoelectron spectroscopy measurements revealed uniform surface functionalization of ultrathin NP SiO2 films by APTES without unwanted self-condensation aggregates. pH-responsibility of APTES modified ultrathin NP SiO2 films (NP SiO2-NH2) were investigated by surface ζ potential and cyclic voltammetry measurements. As a result, ultrathin NP SiO2-NH2 films exhibited selective ion permeation based on electrostatic repulsive or attractive interactions for two different probe ions, Ru(NH3)62+/3+ and Fe(CN)63–/4–, with a similar size but opposite charges. Especially, excellent permselectivity was demonstrated at pH lower than that isoelectric point of ultrathin NP SiO2-NH2 films.