Angle-independent responsive organogel retroreflective structural color film for colorimetric sensing of humidity and organic vapors  

作　　者：Cuiping Ji Jing Zeng Sijia Qin Min Chen Limin Wu 

机构地区：[1]Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers,Fudan University,Shanghai 200433,China

出　　处：《Chinese Chemical Letters》2021年第11期3584-3590,共7页中国化学快报（英文版）

基　　金：supported by National Key Research and Development Program of China(Nos.2017YFA0204600,2018YFE0201701);National Natural Science Foundation of China(No.51673041).

摘　　要：The angle dependence of photonic crystals(PCs)dramatically limits their practical applications in the colorimetrical sensing of humidity and volatile organic compound(VOC)vapors.In addition,it is challenging for inverse opal PCs to colorimetrically distinguish between vapors with similar refractive indices.Different from the mechanism of PC-based sensors,here,we report an angle-independent polyacrylamide(PAAm)organogel structural color film based on the mechanisms of retroreflection,total internal reflection(TIR)and interference with a shape similar to a single-sided“egg waffle”.During the process of responding to humidity and VOC vapors,the color of the film remains angle-independent in the normal angle range of 0°to 45°under coaxial illumination and observation conditions.At the same time,the film can colorimetrically distinguish between vapors with similar refractive indices,such as methanol and ethanol,which is mainly due to the differences in their polarity and solubility parameters.The film shows good stability,reversibility and selectivity when exposed to vapors.A colorimetric sensor with a new response mechanism is proposed and has the potential to effectively distinguish between vapors with similar refractive indices.Furthermore,this responsive retroreflective structural color film(RRSCF)provides a universal strategy to develop targeted angle-independent structural color sensors by selecting optimized materials.

关 键 词：Angle-independent structural color Colorimetric sensing Responsive retroreflective structural color FILM Humidity sensing VOC vapor sensing 

分 类 号：O657.3[理学—分析化学] TB383.2[理学—化学] TP212[一般工业技术—材料科学与工程]