Constructing eco-friendly, PLA/silylpropyl quaternary ammonium graphene oxide composite membrane via chemical grafting for improved oil/water separation and antibacterial performance

In this study, we introduce a novel set of green membranes incorporating cross-linked silylpropyl quaternary ammonium graphene oxide (CSQAGO), designed to leverage the unique properties of graphene oxide (GO) for enhanced oil/water separation. The CSQAGO is inherently functionalized to have increased hydrophilicity, and introduce quaternary functional groups, thereby improved antifouling efficiency. The base membrane was chosen as polylactic acid (PLA) due to its eco-friendly nature. The membranes, synthesized with varying concentrations of CSQAGO (2-6 wt%), are thoroughly characterized to determine their morphological, chemical, and performance-related properties. The MQ6 membrane (6 wt% of CSQAGO) exhibited a 2.2-times increase in water flux (∼195 L⋅m -2 ⋅h -1 ⋅bar -1 ) in compared to the pure PLA membrane with water flux of 90.54 L⋅m -2 ⋅h -1 ⋅bar -1 . The MQ6 membrane showed a significant oil/water separation efficiency of ∼96.92% with improved antifouling properties. Additionally, the MQ6 membrane demonstrated improved E. coli colony inhibition (71.47%) compared to the pristine PLA membrane. • An eco-friendly polylactic acid (PLA) was chosen as a base polymer. • Cross-linked silylpropyl quaternary ammonium graphene oxide (CSQAGO) was designed. • A composite membrane based on PLA/CSQAGO was developed for oil/water separation. • The PLA/CSQAGO membrane showed remarkable oil/water separation performance. • The quaternary ammonium-constructed membrane exhibited antibacterial properties.