Adsorption Properties of Stearyl Acrylate Gel for VOC Observed by QCM-A

摘要

Stearyl acrylate (SA) organogel was synthesized in various solvent systems in this study. The SA gel undergoes an order-disorder phase transition that is dependent on temperature. The swelling properties of the SA gel were investigated as a function of temperature, for a series of liquid volatile organic compounds (VOCs). The swelling volume of the dry SA gels depended on the octanol- water partition coefficient (logPow) and vapor density of the VOCs. Dried SA gel did not absorb or swell in water and lower alcohols, which included the gel synthesized in ethanol and oleyl alcohol. The temperature dependence of the phase of the SA gel was observed from a viscoelastic point of view, using a quartz crystal microbalance with admittance analysis (QCM-A), which was coupled with the gel. The phase behavior of the gel during the temperature scans was identified based on the resonance frequency, fs, and resistance, R, in the QCM oscillation. The adsorption behavior of the SA gel for the series of VOC gases was then investigated using the gel coupled with the QCM as the function of phase of the SA gel. The adsorption properties of the SA gel were also identified using the fs and R from the viewpoint of the viscoelastic phase response of the gel. The difference in adsorption behaviors observed in fs and R, between ordered and disordered phases of the gel, was clarified.