Tailoring of sol-gel films for optical sensing of oxygen in gas and aqueous phase
Tailoring of sol-gel films for optical sensing of oxygen in gas and aqueous phase
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DOI：
10.1021/ac970461b
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发表时间：
1998-01-01
影响因子：
7.4
通讯作者：
McEvoy, AK
中科院分区：
文献类型：
--
作者：
McDonagh, C;MacCraith, BD;McEvoy, AK
基于溶胶-凝胶的气相和溶解氧光学传感器已经开发出来。两种传感器的工作原理都是钌络合物的荧光猝灭原理，钌络合物被包裹在多孔溶胶-凝胶二氧化硅薄膜中。为了确定两种传感环境的最佳胶片处理参数，进行了全面的调查。使用四乙氧基硅烷和有机改性的溶胶-凝胶前体，例如甲基三乙氧基硅烷和乙基三乙氧基硅烷。薄膜疏水性随着改性前体含量的增加而增加，这与增强的溶解氧 (DO) 传感器性能相关。修饰前体的脂肪族基团的扩展进一步提高了 DO 敏感性。研究了水/前体摩尔比 R 对溶胶-凝胶薄膜微观结构的影响。微观结构的 R 值定制和薄膜表面疏水性定制通过气相和 DO 传感的 Stern-Volmer 常数与薄膜中的氧扩散行为相关。气相氧传感器和 DO 氧传感器均具有出色的性能特征。 DO 传感膜的长期淬火稳定性经过 6 个月的时间确定。
Sol-gel-based optical sensors for both gas-phase and dissolved oxygen have been developed. Both sensors operate on the principle of fluorescence quenching of a ruthenium complex which has been entrapped in a porous sol-gel silica film. A comprehensive investigation was carried out in order to establish optimal film-processing parameters for the two sensing environments. Both tetraethoxysilane and organically modified sol-gel precursors such as methyltriethoxysilane and ethyltriethoxysilane were used. Film hydrophobicity increases as a function of modified precursor content, and this was correlated with enhanced dissolved oxygen (DO) sensor performance. Extending the aliphatic group of the modified precursor further improved DO sensitivity. The influence of water/precursor molar ratio, R, on the sol-gel film microstructure was investigated. R value tailoring of the microstructure and film surface hydrophobicity tailoring were correlated with oxygen diffusion behavior in the films via the Stern-Volmer constants for both gas phase and DO sensing. Excellent performance characteristics were measured for both gas-phase and DO oxygen sensors. The long-term quenching stability of DO sensing films was established over a period of 6 months.