Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy.
Faraday Discuss. 2017 Feb 22;196:113-129. doi: 10.1039/c6fd00151c.
We report on vapochromic films suitable for detecting volatile organic compounds (VOCs), based on new polystyrene copolymers containing julolidine fluorescent molecular rotors (JCAEM). Poly(styrene-co-hydroxyethylmethacrylate) copolymers functionalized with cyanovinyl-julolidine moieties of different compositions were prepared, (P(STY-co-JCAEM)(m) with m = 0.06-0.61). The sensing performance of the spin-coated copolymer films demonstrated significant vapochromism when exposed to VOCs characterized by high vapour pressure and a favourable interaction with the polymer matrix, such as EtO and CHCl. It is worth mentioning that the fluorescence decrease rate was 7 times faster than that of previously investigated julolidine-based fluorescent molecular rotors dispersed in PS films. This phenomenon was attributed to the better control of the JCAEM moiety distribution in the polymer matrix conferred by the covalent approach, combined with a minimal film thickness of 4 microns. These factors, in concert, strongly accelerate the deactivation pathways of the JCAEM units in the presence of VOCs which interact well. Overall, the present results support the use of julolidine-enriched styrene copolymers as effective chromogenic materials suitable for the fast detection of VOCs.
我们报道了适用于检测挥发性有机化合物（VOCs）的蒸气致变色薄膜，该薄膜基于含有芴基荧光分子转子（JCAEM）的新型聚苯乙烯共聚物。合成了不同组成的氰基乙烯基-芴基部分官能化的聚（苯乙烯-co-羟乙基甲基丙烯酸酯）共聚物（P（STY-co-JCAEM）（m），其中 m = 0.06-0.61）。旋涂共聚物薄膜的传感性能在暴露于具有高蒸气压和与聚合物基质有利相互作用的 VOCs 时表现出明显的蒸气致变色性，例如 EtO 和 CHCl。值得注意的是，与先前研究的分散在 PS 薄膜中的基于芴基的荧光分子转子相比，荧光猝灭率快了 7 倍。这种现象归因于通过共价键方法更好地控制了聚合物基质中 JCAEM 部分的分布，同时薄膜厚度最小为 4 微米。这些因素共同强烈加速了与良好相互作用的 VOCs 存在时 JCAEM 单元的失活途径。总体而言，目前的结果支持使用富含芴基的苯乙烯共聚物作为有效的显色材料，适用于快速检测 VOCs。
