Abstract: In this study, blends from ethyl cellulose, MCP, TBP,TBAH, and TiO2 was fabricated and the influence of molecular weight of ethyl cellulose, concentration of ethyl cellulose, volume of TBP, drying temperature, and thickness of the film on sensitivity and speed of color change was studied. It showed that the film can change color reversibly in the CO2 concentration range of 0~5 %. The molecular weight of ethyl cellulose should be 80000. The sensitivity increased with decreasing concentration of ethyl cellulose, volume of TBP, thickness of the film, and increasing dying temperature. The speed of changing color became faster with decreasing volume of TBP and increasing thickness of the film. Particularly, recovery time of 300 μm film was increased by three times.

Key words: carbon dioxide, allochromatic film, sensitivity, speed