Development and Characterization of PVA Membranes Modified with In(BTC) Metal–Organic Framework for Sustainable Pervaporation Separation of Isopropanol/Water

In this study, pervaporation membranes from synthetic biodegradable polyvinyl alcohol (PVA) with improved properties for isopropanol dehydration were developed through modification with a synthesized In(BTC) metal–organic framework. The improvement in the PVA membrane properties was achieved by varying the In(BTC) concentration (2.5–7 wt.%) in the PVA matrix to allow us to select the optimal concentration for the membrane, which was further chemically cross-linked with maleic acid to increase the resistance, and developing a cross-linked supported membrane from the optimal PVA/5%In(BTC) composite for promising industrial applications. The synthesized In(BTC) and membranes were characterized by using spectroscopic, microscopic, X-ray diffraction, and thermogravimetric analysis methods, as well as swelling degree, contact angle measurements, and the Brunauer–Emmett–Teller adsorption model. The obtained regularities were confirmed by quantum chemical calculations. The cross-linked supported membrane from PVA/5%In(BTC) had optimal transport properties for isopropanol dehydration (20–90 wt.% water), 99.9–89.0 wt.% water in the permeate, and 0.142–0.341 kg/(m2h) of permeation flux, the rate of which was four times higher compared to the PVA membrane in separating 20–30 wt.% water/isopropanol.