本研究主要探討聚偏二氟乙烯 poly vinylidene fluoride(PVDF)管膜之製備、膜表面特性及其在薄膜蒸餾技術方面的運用。首先?用玻璃纖維以濕式含浸塗佈(dip coating)紡絲法製備 PVDF管膜，溶劑為 NMP，非溶劑為水；藉由改變玻璃纖維管徑、紡絲頭尺寸、鑄膜液與?澱槽之組成，如鑄膜液濃度、溫度、造孔劑種類及濃度等，製作出一系??同孔隙結構及膜厚之管膜。並以 SEM、DSC、XRD、Contact Angle 等檢測分析各種製備條件下之膜表面性質，再?用直接接觸薄膜蒸餾法（direct contact membrane distillation, DCMD）、空氣間隙薄膜蒸餾法(air-gap membrane distillation, AGMD)以及真空薄膜蒸餾法(vacuum membrane distillation, VMD)針對模擬鹽水作淡化實驗，測試通量與拒鹽率。研究操作變數包括：冷熱端溫度變化、熱端流速變化及微溫差對透過率與拒鹽率之影響，預期 PVDF 管膜能有效應用於海水淡化及含鹽廢水回收技術，達到節省能源的目標並得到飲用水標準之滲透水質。 This research investigate the preparation and application in the membrane distillation of porous poly(vinylidene fluoride) (PVDF) tubular membrane. PVDF tubular membranes with different porous structures were prepared by dip coating glass fiber with immersion-precipitation of a casting solution in coagulation baths composed of NMP and water (nonsolvent). The effects of the glass fiber’s diameter, immersion time, polymer solution concentration, and casting solution temperature will investigate. SEM, DSC, XRD, and Contact Angle analyzer were used to characterize the membranes. To enhance MD flux, PVDF in this study, and they were used for the DCMD (direct contact membrane distillation), AGMD (air-gap membrane distillation )and VMD(vacuum membrane distillation) experiments, which tested flux and salt reduction rate through the membrane. This research discussed the effect of little temperature difference, feed flow rate of DCMD and air flow rate of AGMD. Also, the effects of temperature and pressure gradient on the MD membrane performance for purifying drinking water were investigated.
