Effect of humidity and nanocellulose content on Polyvinylamine-nanocellulose hybrid membranes for CO2 capture

Water vapor solubility was also measured and modeled through Park Model to correlate the gas separation properties with the effective content of water present in the membrane matrix. As expected, a higher content of the hydrophilic polymer resulted in a larger water uptake, which at medium to high humidity appeared to trigger a water clustering phenomenon in the matrix. This fact was accompanied by a substantial relaxation of the polymer network, causing a marked reduction of selectivity, which dropped, at the highest RH investigated, to values in the order of 30 and 80 towards CH4 and N2 respectively. Despite this loss in performance, most materials tested still showed very interesting properties, well above Robeson's 2008 Upper Bound, making them an interesting alternative for traditional gas separation processes.