Structure Change of Polyvinylidene Fluoride Membranes Integrating with Carbon Nanotubes and Amphiphilic Surfactant Pluronic

Abstract

Abstract PVDF membranes with the addition of single-walled carbon nanotube (SwC), multi-walled carbon nanotube (MwC), and pluronic additives were studied in this research to determine the characteristics and performance of these membranes in concentrating Lactalbumin from whey protein. The concentration of SwC and MwC used was 0.01%, while pluronic was 3% using dimethyl formamide (DMF) as the organic solvent. The membrane was printed using a phase inversion technique with a thickness of 300 μm and water as a non-solvent solution. The characteristics studied are functional group, morphology, chemical compound, porosity and pore size, and water contact angle (WCA). Meanwhile, membrane performance was evaluated by pure water flux analysis and rejection of the Lactalbumin protein. Membrane morphology with the addition of pluronic produces a finger-like membrane structure with macrovoids covering the bottom and top layers of the membrane. The use of two types of carbon nanotubes, namely SwC and MwC, does not significantly affect the porosity and pore size of the PVDF membrane. Concurrently, adding pluronics increases the porosity and pore size significantly compared to using carbon nanotubes. The results of the WCA analysis also show that the PVDF membrane is more hydrophilic with the addition of pluronics compared to carbon nanotubes alone. On the other hand, this characteristic is in line with the membrane performance results where there is an increase in pure water flux with the addition of pluronic, which is caused by an increase in membrane porosity and pore size as well as a decrease in rejection values compared to SwC and MwC due to an increase in pure water flux. Modifying the PVDF membrane using carbon nanotubes (SwC and MwC) and pluronics affects the characteristics and performance of the membrane in concentrating Lactalbumin from whey protein.