γ-Al_2O_3/TiO_2混合纳米粒子改性PVDF超滤膜

Effects of mixed γ-Al_2O_3/TiO_2 nanoparticles on the structure and performance of PVDF composite membranes

为提高聚偏氟乙烯(PVDF)膜的亲水性和强度,将纳米二氧化钛(TiO2)溶胶和纳米氧化铝(γ-Al2O3)按不同比例与聚偏氟乙烯共混,采用相转化法制得共混超滤膜。考察了不同比例的混合纳米粒子对PVDF超滤膜的纯水通量、截留率、力学性能等的影响。并利用扫描电子显微镜(SEM)观察了膜的表面和内部微观结构,红外光谱分析(FTIR)和X射线衍射仪(XRD)考察纳米粒子在PVDF基体中的存在状态,通过对复合膜进行拉力测试研究混合纳米粒子对膜力学性能的影响,并使用接触角测量仪测定膜表面和水之间的接触角来定量分析比较膜表面的亲水性。结果表明,γ-Al2O3/TiO2混合比为1∶2时,膜的性能达到最优,孔隙率为74%,水通量为120 L/(m2.h),截留率为93%,拉力最大负荷为35 N,拉伸应变为22%。

Mixed TiO2 sol and γ-Al2O3 nanoparticles in different proportions can increase hydrophilic and mechanical strength of PVDF membrane by phase-inversion.The effects of TiO2 sol and γ-Al2O3 nanoparticles on pure water flux,retention rate and mechanical properties of UF were discussed.The γ-Al2O3-TiO2/PVDF membrane surface and section structure were characterized by SEM,FTIR spectroscopy,X ray diffraction analyzer（XRD）.In addition,membrane mechanical properties and hydrophilicity were tested by tensile tester,contact angle goniometer.Membrane performance reached optimal when the γ-Al2O3/TiO2 mixed was 1∶2,with porosity 74%,flux 120 L/（m2？h）,retention rate 93%,tensile strength maximum loading 35N and tensile strain 22%.