Preparation of organic-inorganic hybrid polymers and their humidity sensing properties

Abstract

Water-resistance and defined structure are important characteristics for the polymers used in humidity sensors. Here, cross-linked organic-inorganic hybrid polymers based on mercaptopropyl polyhedral oligomeric silsesquioxane (MPOSS), 1,4-divinylbenzene (DVB) and methacrylatoethyl trimethyl ammonium chloride (DMC) with defined structures have been synthesized via click chemistry. The structures of the resultant polymers were characterized by Fourier transform infrared spectra (FT-IR). Humidity sensors based on the cross-linked polymers were fabricated and their humidity sensing properties were systematically investigated. The impedance modules of the optimized sensor change about three orders of magnitude over the relative humidity range from 11% to 95%. The obtained sensor also shows small humidity hysteresis and rapid response to humidity change.