Abstract:Polyvinylidene fluoride (PVDF) ultrafiltration membranes modified by nano-ZnO are prepared by phase inversion method to improve their hydrophilicity and enhance application in water treatment. The effects of nano-ZnO amount on the structure and performances of the membranes are investigated. The porosity, hydrophilicity, microstructure, mechanical strength, pure water flux, protein rejection and flux recovery efficiency are characterized by porosity measurement, contact angle measurement, scanning electron microscopy (SEM), atomic force microscopy (AFM), mechanical property test and ultrafiltration experiments, respectively. The results show the following. When the mass fraction of nano-ZnO is 0.2%, the contact angle of the membrane is decreased from 76.3° to 63.4°, indicating a significant hydrophilic improvement. The porosity increases from 53.4% to 54.1% and the tensile strength increases from 2.09 MPa to 2.82 MPa. Pure water flux, protein rejection and flux recovery efficiency are improved to a certain degree. The cross-section structure of the membrane is regular, the size of finger-like hole is large and the surface of the membrane is smooth.
[1] Vijay K T, Eu J T, Lin M F, et al. Polystyrene grafted polyvinylidenefl uoride copolymers with high capacitive performance[J]. Polymer Chemistry, 2011, 2(9): 2000-2009.
[2] Fontananova E, Bahattab M A, Aljlil S A, et al. From hydrophobic to hydrophilic polyvinylidenefluoride (PVDF) membranes by gaining new insight into material's properties[J]. RSC Advances, 2015, 5(69): 56219-56231.
[3] Ouyang G, Hussain A, Li J, et al. Remarkable permeability enhancement of polyethersulfone (PES) ultrafiltration membrane by blending cobalt oxide/graphene oxide nanocomposites[J]. RSC Advances, 2015, 5(86): 70448-70460.
[4] 孙鸿, 宋华, 芦艳. Al2O3/TiO2/PVDF杂化超滤膜的制备及其性能研究[J]. 功能材料, 2012, 43(18): 2558-2563. Sun Hong, Song Hua, Lu Yan. Preparation and performances research of Al2O3/TiO2/PVDF hybrid ultrafiltration membrane[J]. Functional Materials, 2012, 43(18): 2558-2563.
[5] Wang Q Y, Wang Z W, Zhang J, et al. Antifouling behaviours of PVDF/ nano-TiO2 composite membranes revealed by surface energetics and quartz crystal microbalance monitoring[J]. RSC Advances, 2014, 4(82): 43590-43598.
[6] Yu L Y, Xu Z L, Shen H M, et al. Preparation and characterization of PVDF-SiO2 composite hollow fiber uf membrane by Sol-Gel method[J]. Journal of Membrane Science, 2009, 337(2): 57-65.
[7] Lu Y, Yu S L, Chai B X, et al. Effect of nano-sized Al2O3-particle addition on PVDF ultrafiltration membrane performance[J]. Journal of Membrane Science, 2006, 276(1/2): 162-167.
[8] Balta S, Sotto A, Luis P, et al. A new outlook on membrane enhancement with nanoparticles: The alternative of ZnO[J]. Journal of Membrane Science, 2012, 389: 155-161.
[9] Hong J M, He Y. Effects of nano sized zinc oxide on the performance of PVDF microfiltration membranes[J]. Desalination, 2012, 302: 71-79.
[10] Pang R Z, Li X, Li J S, et al. In situ preparation and antifouling performance of ZrO2/PVDF hybrid membrane[J]. Acta Physico-Chimica Sinica, 2013, 29(12): 2592-2598.
[11] Du J, Wu L, Tao C Y, et al. Preparation and characterization of Fe3O4/ PVDF magnetic composite membrane[J]. Acta Physico-Chimica Sinica, 2004, 20(5): 98-107.
[12] Yang J M, Zhang W, Liu Q, et al. Porous ZnO and ZnO-NiO composite nano/microspheres: synthesis, catalytic and biosensor properties[J]. RSC Advances, 2014, 4(93): 51098-51104.
[13] 荣华, 王富美, 王岁, 等. 微/纳米ZnO绒球的制备及对混合污水的光降解[J]. 石油化工高等学校学报, 2015, 28(1): 7-11. Rong Hua, Wang Fumei, Wang Sui, et al. Preparation of micro/nano ZnO pompons and its activity on photodegradation of dyeing sewage[J]. Journal of Petrochemical Universities, 2015, 28(1): 7-11.
[14] 李秀萍, 李秀荣, 赵荣祥, 等. 均匀沉淀法制备纳米ZnO及其光催化研究[J]. 辽宁石油化工大学学报, 2014, 34(1): 39-42. Li Xiuping, Li Xiurong, Zhao Rongxiang, et al. Preparation of nano-ZnO with homogeneous precipitation and its photocatalytic properity[J]. Journal of Liaoning Shihua University, 2014, 34(1): 39-42.
[15] Soroko I, Livingston A. Impact of TiO2 nano particles on morphology and performance of cross-linked polyimide organic solvent nano filtration (OSN) membranes[J]. Journal of Membrane Science, 2009, 343(1/2): 189-198.