The fabrication of gas sensor using the resonant frequency and admittance of quartz crystal analyzer

The adsorption and desorption behavior of organic vapours for polymeric sensitive LB film was investigated using the resonant frequency and resistance method of a quartz crystal microbalance. A new method was used to analyze the response mechanism between organic vapours and polymeric sensitive LB films. When the organic vapours were adsorbed into sensitive LB films, the rheological changes in LB films were observed by the quartz microbalance resonant method. To investigate the characteristics of organic vapours, a resonant frequency-resonant resistance (F-R) diagram was used. The quantitative information about organic vapours adsorbed and quantitative change of sensitive LB films can be obtained. In experimental results, the response of organic vapours can be separated into two types; surface adsorption and penetration into sensitive LB films. The response mechanism between organic vapours and sensitive LB films can be obtained from the F-R diagram.