Title: | Gas-Sensing Mechanism of Silica with Photonic Bandgap Shift |
Author(s): | Xie J; Duan M; Bai P; Lei K; Yang C; Liu B; Zhang L; Tang J; Wang Y; Wang H; |
Address: | "School of Materials Science and Engineering , Southwest Petroleum University (SWPU) , Chengdu 610500 , China. Mechanical and Aerospace Engineering Department , University of California , Los Angeles , California 90095 , United States. College of Chemistry and Chemical Engineering , Southwest Petroleum University (SWPU) , Chengdu 610500 , China" |
DOI: | 10.1021/acs.analchem.8b04874 |
ISSN/ISBN: | 1520-6882 (Electronic) 0003-2700 (Linking) |
Abstract: | "Two physical models, the replacing model and the filling model, have been proposed to explain the mechanism of the effective-refractive-index change of photonic crystals (PCs). Theoretically, the photonic bandgap (PBG) would shift when PCs are exposed to different environments, which leads to a change of the effective refractive index of PCs. However, the mechanism of effective-refractive-index change is distinct when PCs are placed in different gases or vapors. Here, silica PCs were successfully fabricated by a self-assembly method. The PBG of silica PCs exhibit similar redshifts in volatile organic compounds (VOCs) and in small-molecule gases. We propose a replacing model to elaborate silica PCs exposed to VOCs and a filling model to explain silica PCs exposed to small-molecule gases. Additionally, the redshift of PBG was transformed into the volume fraction of adsorbed gas in order to achieve selective sensing of silica PCs. The approach could be exploited for applications in sensing" |
Notes: | "PubMed-not-MEDLINEXie, Juan Duan, Ming Bai, Penghui Lei, Kai Yang, Chen Liu, Biao Zhang, Lei Tang, Junlei Wang, Yingying Wang, Hu eng 2018/12/05 Anal Chem. 2019 Jan 2; 91(1):1133-1139. doi: 10.1021/acs.analchem.8b04874. Epub 2018 Dec 13" |