Al2O3/TiO2/PVDF杂化超滤膜的制备及其性能研究

为提高聚偏氟乙烯(PVDF)超滤膜的亲水性,增强其在水处理中的抗污染能力,用无机纳米二氧化钛(TiO2)、氧化铝(Al2O3)与聚偏氟乙烯共混,采用相转化法制得无机改性有机高分子杂化超滤膜。采用杯式超滤装置考察了无机纳米颗粒的含量对杂化膜水通量的影响;测定了膜的纯水接触角、机械性能、截留效率和膜的孔径及孔径分布;采用扫描电子显微镜对膜表面进行观察。结果表明,纳米颗粒加入量为3%,TiO2与Al2O3的加入比为1∶1时,杂化膜的水通量较有机膜提高了79.5%,但截留率保持不变;杂化膜的机械强度最大增加41.6%;杂化膜的纯水接触角由未改性前的78.68°降至50.54°,亲水性得到明显改善;杂化膜的平均孔径增大,孔径分布更加均匀;纳米颗粒的加入增加了膜表面的孔密度,但没有改变膜断面的微观结构。杂化超滤膜不仅保持了PVDF膜的优良性能,而且增强了其强度、亲水性和抗污染性能。

Preparation and performances research of Al2O3/TiO2/PVDF hybrid ultrafiltration membrane

The polymer polyvinylidene fluoride(PVDF) membranes were modified by blending with nanometer particles to improve its hydrophilic property and anti-fouling performances in water treatment.The organic macromolecule blended ultrafiltration(UF) membranes modified by the inorganic nanometer TiO2 and Al2O3 were prepared by the phase inversion process.The cup ultrafiltration set was employed to study the effects of nanometer particles addition on the permeation performances of hybrid membrane.The experimental results showed that the hybrid membrane water flux increased with 79.5% than that of organic membrane with 3% nanometer particles addition and the proportion of TiO2 and Al2O3 was 1∶1,but its rejection rate did not change.The tensile strength of the hybrid membrane increased 41.6%;pure water contact angle of hybrid membrane dropped from78.68° to 50.54°,which improved the hybrid membranes hydrophilic.The hybrid membrane average pore size was larger than that of organic membrane and the pore size distribution was more uniform.The pore density of the membrane surface was increased due to nanometer particles addition,but without changing the membrane’s microscopic cross section structure.The hybrid UF membrane not only maintained PVDF membrane’s favorable performances but also improved its intensity,hydrophilic and anti-fouling performances.