Properties and preparation of TiO2-HAP@PVDF composite ultrafiltration membranes

The non-solvent induced phase separation technology was introduced to formulate titanium dioxide (TiO2)-hydroxyapatite (HAP) composite modified polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes, and research was conducted to explore the effect on PVDF UF membrane performance exerted by different addition amounts (0-1.0?wt%) of TiO2-HAP composite. The results indicated that when 0.3% TiO2-HAP composite was added, the composite membranes had a through-channel structure, with a uniform pore structure on the surface, so that they possessed a certainly raised pure water flux. Specifically, in contrast to the pure PVDF membrane, 0.3%-TiO2-HAP@PVDF UF membrane exhibited an incremented pure water flux by 59.09%. Besides, TiO2-HAP@PVDF UF membranes had decreased rejection rate of bovine serum albumin (BSA) together with water contact angle to 58.62% and 70.17 degrees, respectively, compared to the pure PVDF membrane (85.52% & 92.75 degrees), showing good hydrophilicity. Several pure water flux tests on the composite UF membranes revealed that the flux tended to be stable after the 4th test. In summary, the addition of TiO2-HAP composite is capable of efficiently ameliorating PVDF base membranes from the aspects of microstructure, hydrophilicity, antifouling properties, as well as stability, allowing a good application prospect in actual water treatment.

Automated summary

The non-solvent induced phase separation technology was used to develop modified polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes with titanium dioxide (TiO2)-hydroxyapatite (HAP) composite. The addition of 0.3% TiO2-HAP composite resulted in improved membrane performance, with increased pure water flux and reduced rejection rate of bovine serum albumin (BSA) and water contact angle. The composite membranes also showed stable flux after multiple tests, indicating good stability. These findings suggest that TiO2-HAP composite has great potential in water treatment applications.