The influence of filler type on the separation properties of mixed-matrix membranes

Chitosan-based membranes filled with different metal oxide particles were prepared and their performance in ethanol dehydration process depending on the type of oxide and loading was discussed. For membrane preparation three oxides: TiO₂, Cr₂O₃ or Fe₃O₄ were selected. From experimental data suitable ethanol and water transport coefficients were evaluated. As shown in the results, applied fillers in different ways affect the separation properties. Presence of TiO₂ significantly affects the normalized total flux, increasing its value. On the other hand, addition of Fe₃O₄ influences most of all the separation factor, which is the among all investigated membranes. For membranes containing chromium(III) oxide as a filler, improvement in the separation properties is observed only in the case when the Cr₂O₃ content equals to 5 wt%. Above this concentration significant deterioration of separation properties is observed. The best performance has mixed-matrix membranes (MMMs) with magnetite, where the values of PSI are equal to 16.3 and 296.8 kg/m^-2 h µm for pristine and 15 wt% filler content, respectively.