A fundamental and applied study of the ionic liquids as gas sensing materials.

摘要

This work is about fundamentals and applications of gas sensors based on sensing materials of ionic liquids (IL) and sensing device of quartz crystal microbalance (QCM). In addition to the introduction and experimental details, this dissertation includes four projects.;First, ILs were used as sensing materials of high temperature gas sensor array. Due to the large diversity of ILs in structure, the IL sensor array showed excellent capability for sample gas classification and identification. Spectroscopic and thermodynamic investigations explained the different interactions between ILs and gases.;Second, in order to increase the sensitivity of QCM/IL gas sensors, a polymer template polyaniline was used to increase the amount of immobilized ILs on QCM's surface. This strategy was confirmed by the detection of methane at very low concentration. It was also found that polyaniline and IL might form complex with specific structures for methane absorption.;Third, to miniaturize the QCM sensor array and to make it portable, a four-QCM sensor array was prepared on a monolithic quartz plate. This monolithic multiple QCM sensor array was proved to be as powerful as regular sensor array containing multiple individual QCMs.;Fourth, the QCM IL sensors were used to detect explosive materials and water. The damping resistance change upon absorption of gases was discussed.;In summary, this dissertation provides fundamental knowledge about the interaction of ILs and gases and the performance of ILs as gas sensing materials. Effective and successful methods have been explored to improve the sensitivity, selectivity and the detecting device.