Novel Translucent Hollow Fiber Polyvinylidene Fluoride Photocatalytic Membrane: The Role of Translucency on Degradation Efficiency

A novel thermally modified non-solvent induced phase separation (T-NIPS) fabrication method to produce translucent hollow fiber PVDF (THF-PVDF) photocatalytic membrane is developed. This method relies on attacking polymer crystalline property of PVDF by two steps temperature treatment process involving melting at high temperature (200°C) and rapid cooling at 0°C during spinning process thereby producing more γ-phase crystalline structure PVDF. The effect of membrane translucency on the photodegradation efficiency of immobilized photocatalyst were assessed. Graphitic carbon nitride in modified morphological structure (hollow nanofiber) were utilized. Membrane’s rejection, pure water flux and permeate flux of oil produced water were also investigated. The overall data shows that the produced membrane exhibits high translucency between 60.0% and 93.9% with THF-PVDF/PVP-GCN (2.0) exhibiting the highest. Comparatively, the filtration experiment on membrane with GCN photocatalyst showed high pure water flux (1200 L/m2h) and rejection (90%) of OPW than bare THF-PVDF and THF-PVDF/PVP. The photodegradation of GCN in suspended mode showed 99.98% degradation. The efficiency of GCN when immobilized in translucent membrane showed 95% photodegradation while membrane that is produced following commercial NIPS method showed only 49.40% photodegradation of OPW. This excellent performance is attributed by the transparency of membrane where the penetration of light is fully accommodated to the produced translucent photocatalytic membrane. The translucent photocatalytic membrane's preparation process and exceptional degradation efficiency meet the demands of current industrial productivity while also offering a bright application prospect for the industry.