Fourier transform infrared spectroscopy and oxygen luminescence probing combined study of modified sol–gel derived film

Abstract A series of sol–gel-derived silica films are prepared by co-condensation of vinyltrimethoxysilane (VTMOS) and tetraethoxylsilane (TEOS) with various feeding molar ratios of VTMOS to TEOS under the acid-catalyzing conditions. Significant improvements of the performance of film formation are observed in these vinyl modified films. The resultant silica films are characterized by Fourier transform infrared (FT-IR) spectroscopy giving some important structural features. The main SiOSi vibrations shift to low wavenumber with increasing VTMOS ratios indicating more open network structures in these vinyl-containing films. The vibration bands of SiOH (3100–3700 cm −1 ), and especially H 2 O (1640 cm −1 ), in the silica films are weakened with increasing VTMOS contents, revealing that the introduction of vinyl group into sol–gel systems can increase the degree of condensation and hydrophobicity of porous surface. Luminescence probing of resultant sol–gel films with Ru(bpy) 2+ complex as probe show more rapid and sensitive response to oxygen against standard TEOS-based silica film. The improvement of oxygen-sensing property can correspond to the structural characteristics obtained from IR spectroscopy.