Effect of Polyvinylpyrrolidone on Polyvinylidene Fluoride/Hydroxyapatite-Blended Nanofiltration Membranes: Characterization and Filtration Properties

Introduction: The application of polyvinylidene fluoride (PVDF) as a filtration membrane is limited due to its hydrophobicity. This paper elaborated on the fabrication process of nanofiltration PVDF membrane incorporating various quantities of hydrophilic polyvinylpyrrolidone (PVP) and hydroxyapatite (HA) using a wet phase inversion method to improve its hydrophilicity. Methods: The membrane was fabricated by using the wet phase inversion method. It was then characterized in terms of water permeability, water contact angle, water content, surface energy, and surface porosity. Bacteria and Fe ions filtration was conducted to investigate the membrane filtration performance. Results: The PVDF/PVP/HA-blended membrane showed the highest water permeability (6,165 LMH/Bar), water content (45.2%), and surface energy (104.1 mN/m) when 2 wt.% of PVP was introduced into the base polymer PVDF. This fabricated membrane, labeled as PVP 2.0, also showed the lowest contact angle (64 degrees) and the highest surface porosity (42%). Conclusion: Overall, the PVP introduction patents into the polymeric membrane doping solution potentially improves membrane hydrophilicity and permeability.