Solubility and Diffusivity of Alcohols and Water in Thin Matrimid Films

The eventual decreasing availability of fossil fuels has presented the need for biofuel conversion efficiency to provide economically viable solutions. This research investigates the application of polymeric membrane reactors for three-phase hydrogenation reactions, specifically interactions between reaction solvents and polymer, including penetrant sorption and diffusion. Typically, these types of studies are performed on thick polymer films on the order of 1 to 100µm. However, we are investigating the dense, thin layer of asymmetric polymer membranes on the order of 0.1 to 1 µm with a quartz crystal microbalance (QCM), which acts as a piezoelectric transducer providing frequency data of a quartz crystal due to the applied alternating current. For this research, the QCM is used to determine sorption and diffusion properties of short-chain alcohols on Matrimid polymer films. Additionally, it determines optimal spin parameters and how the polymer solution’s weight percent affects the mass deposited on the crystal as the thin polymer coatings on the quartz crystals are obtained using spin-coating techniques. The sorption data gathered used 1 and 2 wt% Matrimid in dichloromethane (DCM). Spin parameters were analyzed for both 1 and 2 wt% solutions with spin velocities ranging from 1500 to 3000 rpm and accelerations ranging from 250 to 750 rpm/s. The results showed that acceleration affected the polymer thickness more than changing the velocity in both cases. The thickness of the deposited Matrimid increased from 0.0665 μm to 1.217 μm as the weight percent of Matrimid in DCM increased from 0.5 wt% to 4 wt%.