Anchoring of self-curable ionene-containing polyesters to electrode surface by UV irradiation and their humidity-sensitive properties

I am reporting a simple effective way to photochemically attach polyelectrolyte layer to solid electrode surface. The system is based on photoreactive chalcone-containing polyesters that are bound to alumina surfaces via chalcone-containing alkoxysilane anchoring agent. The alumina substrate is then converted to a chalcone film that is reacted with the polyelectrolyte by irradiating UV light. As a result of photochemical reaction, humidity-sensitive polyelectrolyte is covalently bound to the electrode surfaces. As examples, we have successfully attached thin layer of polyesters obtained by reacting ionene-containing diphenol (IDP) and 4,4′-dihydroxy chalcone (DHC) with terephthaloyl chloride to the electrode surface via the photocrosslinking reaction. The pretreatment of the substrates with chalcone-containing silane-coupling reagents was performed for improving the water durability and stability of the humidity sensors at high temperature and high humidity. Their water durability, high temperature/humidity stabilities and long-term stability were highly improved and evaluated as a humidity-sensing membrane.