(380z) Filler Surface Effects on Mixed Matrix Pervaporation Membrane Performance: Ethanol Dehydration Study and Permeation Modeling

In chemical process industries, energy consumption in separation processes is a significant concern for sustainability. In many cases, membrane technology offers a sustainable solution. For chemical dehydration, traditional hydrophilic polymeric membranes face challenges due to the trade-off between permeation flux and separation factor, known as the permeability-selectivity trade-off. Fabrication of mixed matrix membranes offers a solution by providing faster selective diffusive transport pathways through fillers. Yet, their performance relies heavily on filler surface properties and interaction with the polymer matrix, with filler wettability being crucial in pervaporation operations. Furthermore, non-ideal interaction morphologies make pervaporation modeling complicated and limited for ideal filler-matrix interaction. In this study, state of the art fillers are synthesized from lignocellulose precursor by pyrolysis. These Carbon Molecular Sieves (CMS) fillers exhibit varying surface properties namely hydrophobic to hydrophilic depending on pyrolysis condition. These fillers are incorporated into a hydrophilic polymeric matrix. Our pervaporation investigation and membrane characterization reveal varying classes of polymer interaction at the same filler loading, indicating the importance of filler surface properties in membrane transport. Additionally, we observe chain rigidification with hydrophilic fillers and increased void fraction with hydrophobic fillers. Our experimental study employs an ethanol-water (90:10) system to assess pervaporation performance. Relative permeability was also evaluated under modified Felske models, Maxwell transport model and a proposed composite transport modeling with filler interaction. Our study underscores the ongoing efforts in tailoring filler properties to specific separation requirements, opening new avenues for sustainable membrane separation.