Pervaporation separation of isopropylbenzene from water using four different polymeric membranes: Membrane preparation, modification, characterization, and performance evaluation

Abstract

In the present study, for the first time, the separation of isopropylbenzene as a volatile organic compound (VOC) from water was investigated through the pervaporation (PV) process. Polyvinylidene fluoride (PVDF), polydimethylsiloxane (PDMS), polyether block amide (PEBA), and ethylene-propylene-diene monomer (EPDM) polymers were utilized in the preparation of PV membranes, and their performance and properties were compared. With respect to the results, the PVDF membranes had the highest PV separation index (PSI) equal to 66,486.6 g/m2h. In addition, this membrane had the highest Young's modulus and tensile strength, together with a low swelling degree. However, it had the lowest water contact angle and thus, was further modified. For this purpose, for the first time, Span 85 was used as an additive in the structure of PV membranes. The membrane characterizations implied the increased hydrophobicity and decreased swelling of the PVDF/Span 85 membrane in comparison with the pure PVDF membrane. The PV results revealed that the addition of 2 wt% Span 85 to the PVDF membrane was followed by an improvement in the separation factor so that it resulted in increased PSI (105,761.9 g/m2h).