Quantitatively extracted Gibbs free-energy (ΔG) as criterion to determine working temperature range of gas sensing-material

Abstract

Micro-gravimetric resonant microcantilever is firstly used as a tool to determine the working temperature-range of molecule-adsorbing type sensing material. According to the criterion of ΔG(T)=ΔH-TΔS≥0, the maximum working-temperature (Tmax) for molecule-adsorbing function of the material can be obtained. This method is successfully used to determine the Tmax for two organophosphorus sensitive materials of mesoporous-silica and nano-spheric Stöber silica. The obtained results with the extracting method are verified by adsorbing/sensing experiment.