| Title: | Highly Selective Gas Sensor Based on Hydrophobic Silica Decorated with Trimethoxyoctadecylsilane |
| Author(s): | Xie J; Zhang L; Liu B; Bai P; Wang C; Xu J; Wang H; |
| Address: | "School of New Energy and Materials, Southwest Petroleum University (SWPU), Chengdu 610500, China" |
| Journal Title: | ACS Appl Mater Interfaces |
| ISSN/ISBN: | 1944-8252 (Electronic) 1944-8244 (Linking) |
| Abstract: | "Trimethoxyoctadecylsilane (OTMS) was successfully used to decorate mesoporous silica with a self-assembly method to enhance the relative gas selectivity. A quartz crystal microbalance was employed to measure the gas-sensing properties. The content of OTMS was the crucial factor that greatly affected the adsorption capacity (q) of silica, which could be converted to relative selectivity (S) to study the sensing mechanism. With increasing OTMS content, q was far higher for small-molecule gases compared to volatile organic compounds (VOCs), which could be explained by the polarity of the bonding objects, and S reached a maximum value of 45.71%. When exposed to VOCs, S was always greater than 0 among the three alcohols. The sensing mechanisms of undecorated silica and OTMS-decorated silica were quite different; the three-state mechanism was proposed to explain the sensing mechanism of OTMS-decorated silica. When exposed to small-molecule gases, the atoms that bonded with carbon atoms on OTMS greatly influenced q. With increasing OTMS content, the bonding energy of OTMS with CO(2) was far less than that with other molecules, resulting in a relative selectivity as high as 38.69%. Furthermore, macroperformance and microproperties were combined in three-dimensional coordinates, which could be applied to predict the sensing performance of silica" |
| Keywords: | gas sensor relative selectivity silica steric effect trimethoxyoctadecylsilane; |
| Notes: | "PubMed-not-MEDLINEXie, Juan Zhang, Lei Liu, Biao Bai, Penghui Wang, Chenjie Xu, Jiake Wang, Hu eng 2020/12/23 ACS Appl Mater Interfaces. 2021 Jan 13; 13(1):1956-1966. doi: 10.1021/acsami.0c18582. Epub 2020 Dec 22" |
