EFFECT OF CARBON-DIOXIDE ON THE ELECTRICAL-CONDUCTIVITY OF POLYETHYLENE GLYCOL-ALKALI CARBONATE COMPLEX FILM

A solid film consisting of triethylene glycol, K2CO3-polyethylene glycol of high mol. wt., was prepared on a sintered alumina substrate with a pair of golden electrodes and their electrical conductivity was measured. When CO2 gas was introduced into the air, the conductivity decreased. This change was reversible. The sensitivity to CO2, designated as (change in conductivity caused by CO2)/(conductivity in air), was the highest when a polyethylene glycol of mol. wt. 6000 was used. The sensing mechanism was interpreted in terms of the change in concentration of the charge carrier K+ ion by CO2.