COMPOSITE MEMBRANE FOR GAS SENSOR, GAS SENSOR, AND METHOD FOR MANUFACTURING COMPOSITE MEMBRANE FOR GAS SENSOR

摘要

PROBLEM TO BE SOLVED: To measure the concentration of carbon dioxide continuously accurately in the vicinity of room temperature. SOLUTION: A composite membrane for a gas sensor includes a conductive polymer 1 such as base-type polyaniline(PAn) and an insulating polymer 2 such as polyvinylalcohol(PVA) as material. Base-type PAn is obtained by subjecting a powder of polyanthranilic acid(PANA) to heat treatment at a predetermined temperature for a predetermined time. The base-type PAn is dissolved in dimethyl sulfoxide(DMSO) and then mixed with a PVA/DMSO solution to create a composite solution. Then the composite solution is cast into a micro platinum comb electrode formed on a glass substrate, and a solvent is removed by vacuum drying to obtain a gas sensor. In this gas sensor, HCO3 is created by the reaction between CO2 gas and water held by PVA, and the created HCO3 is captured in the base-type PAn as a dopant to change the electric conductivity of a composite membrane.