Search for: All records

Zwitterionic polymers have proven to be a promising non-fouling material that can be applied in the design of selective layers of thin film composite (TFC) membranes. Extending the permeability and usage of TFC membranes have attracted increasing interest in membrane-based desalination processes since water-flux reduction associated with biofouling persist nowadays as a common challenge. By virtue of its strong hydration, this polymer category is very useful to counteract biofouling in marine and biomedical systems, but the benefits from their application in membrane technology are still emerging. The efficacy of the non-fouling property as a function of the polymer’s molecular weight remains unknown. In pursuit of that vision, this study fosters new scientific insights via probing different molecular weights of poly(carboxybetain methacrylate) (PCBMA) coated on the surface as a selective layer for the prepared TFC membranes. The coated zwitterionic membranes (zM) exhibited excellent performance to prevent water flux decay in a bench scale forward osmosis system. The prepared zM membranes revealed enhanced hydrophilic properties and retained its operational water-flux when compared to the control. Our results suggest that using an intermediate size molecular weight (PCBMA Mn 50,000) will result in the best operational performance. The intermediate size resulted in the lowest flux decline rate (Rt) of 0.01±0.001 (zM-50) when compared to the unmodified control membrane 0.56 ± 0.071 (M0) after using a model BSA foulant solution. Furthermore, all coated membranes exhibited similar trends in the observed reverse salt flux profiles as well. The constructed zM membranes will serve as a model to develop further selective layers in the construction of TFC membranes.