凝固浴组成对热诱导相分离法制备PVDF微孔膜形态结构的影响
作者:王旭东1,张凯1,王磊1,黄丹曦1,吕永涛1,孟晓荣2,付小康1
单位: 1.西安建筑科技大学环境与市政工程学院,陕西 西安,710055;
关键词: 聚偏氟乙烯;混合稀释剂;热致相分离法;非溶剂致相分离法;形态结构
出版年,卷(期):页码: 2015,35(5):51-57

摘要:
以二乙二醇单乙醚醋酸酯(DCAC)和磷酸三乙酯(TEP)的混合溶剂为稀释剂,采用热诱导相分离法制备PVDF平板微孔膜,获得了不同形态结构的膜。借助SEM、DSC、XRD等技术手段考察了凝固浴组成对PVDF微孔膜形态结构的影响。结果表明:在低温凝固浴(0oC)中形成的膜均表现出颗粒状镶嵌晶体结构的断面。随着DMAC含量的增加,膜断面厚度增大,膜表面皮层厚度减小。膜的上表面形态主要取决于凝固浴组成,随着凝固浴中DMAC含量的增加,上表面由致密变得多孔。膜的结晶特性分析表明,所有的膜PVDF主要结晶成α-相晶体结构,随着凝固浴中DMAC含量的增加,膜的结晶度降低,并伴生有γ-相晶体结构。此外,随着凝固浴中DMAC含量的增加,膜的平均孔径和孔隙率增大,但拉伸强度降低。
 
The polyvinylidene fluoride ( PVDF) flat membrane was prepared via thermally induced phase separation method using diluent mixtures oftriethylphosphate(TEP)and diethylene glycol monoethyl ether acetate(DCAC),membranes with different structures and morphology are obtained. The effects of coagulation baths on the structures and morphology of PVDF membrane were investigated with SEM,DSC,XRD and other technologies. The result shown that all membrane precipitated from different coagulation baths at low temperature of 0oC were showed granular mosaic crystal structure of the cross-section. With increasing of DMAC content in baths,the cross-section thickness of membrane increases,but the surface layer thickness of membrane decreases. The different coagulation baths strongly influenced the top surface of the membranes.With increasing of DMAC content in coagulation baths,the top surface of membrane by the density become porous.The analysis of membrane crystallization characteristics indicates that all of the membrane PVDF main crystal into alpha phase,with increasing of DMAC content in the coagulation bath,the crystallinity of membrane is decreased,andassociated with gamma phase crystal formation. In addition,by increasing the DMAC content in the coagulation bath,membrane average pore diameter and porosity increases,but the membrane strength decreases.
 
王旭东(1979~),男,博士,副教授,主要研究方向为膜法水处理技术

参考文献:
[1] K H Oshima,T T Evans Strickfaden,A K Highsmith,et al. The Use of a Microporo-us Polyvinylidene Fluoride (PVDF) Membr-ane Filter to Separate Contaminating Viral-Particles from Biologically Important Protei-ns[J]. Biologicals,1996,24:137-145.
[2] S P Deshmukh,K Li. Effect of ethanol co-mposition in water coagulation bath on mo-rphology of PVDF hollow fibre membranes[J]. J Membr Sci,1998,150:75-85.
[3] T H Young,LPCheng,DJ Lin,et al. Me-chanisms of PVDF membrane formation by immersion-precipitation in soft (1octanol)  and harsh (water) nonsolvents[J]. Polymer, 1999,40:5315-5323.
[4] D R Lloyd,K E Kinzer,H S Tseng. Mic-roporous membrane formation via thermally induced phase separation. I. Solid-liquid  phase separation[J]. J Membr Sci,1990,52:239-261.
[5] A Cui,Z Liu, C Xiao,et,al. Effect of  micro-sized SiO2-particle on the performan-ce of PVDF blend membranes via TIPS[J]. J Membr Sci,2010,360:259-264.
[6] V V Shirkova,S P Tretyakova. Physical a-nd chemical basis for the manufacturing of fluoropolymer track membranes[J]. Radiati-on Measurements,1997,28:791-798.
[7] M. Grasselli,N. Betz. Making porous mem-branes by chemical etching of heavy-ion tr-acks in β-PVDF films, Nuclear Instrumen-ts and Methods in Physics Research Sectio-n B: Beam Interactions with Materials and Atoms,2005,236:501-507.
[8] B J Cha,J M Yang. Preparation of poly(vi-nylidene fluoride) hollow fiber membranes  for microfiltration using modified TIPS pr-ocess[J]. J Membr Sci,2007,291:191-198.
[9] F Liu,Mm Tao,Lx Xue. PVDF membranewith inter-connected pores prepared via a  Nat-ips process[J]. Desalination,2012,298:99-105.
[10] 肖凯军,熊璞. 混合稀释剂制备PVDF微孔膜的结构与性能研究[J]. 塑料工业,2010, 38(12):10-13.
[11] Y Rosenberg,A Siegmann,M Narkis,S Shkolnik. The sol/gel contribution to the b-ehavior of γ-irradiated poly(vinylidene fluor-ide)[J]. JAppl Polym Sci, 1991,43:535-541.
[12] J F Li,Z L Xu,H Yang. Microporous p-olyethersulfone membranes prepared under  the combined precipitation conditions with non-solvent additives[J]. Poly Adv Technol,2008,19:251-257.
[13] AFM Barton. CRC Handbook of Solubility Parameters and Other Cohesion Parameters[M],Second Edition. CRC press,1991.
[14] Q Li,Z L Xu,M Liu. Preparation and c-haracterization of PVDF microporous mem-brane with highly hydrophobic surface[J].  Poly Adv Technol,2011,22:520-531.
[15] 徐国强. 热致相分离法制备聚偏氟乙烯多孔膜[D]. 天津:天津工业大学,2000.
[16] H Matsuyama,Y Takida,T Maki,et,al.Preparation of porous membrane by combi-ned use of thermally induced phase separat-ion and immersion precipitation[J]. Polyme-r,2002,43:5243-5248.
[17] Z Song,M Xing,J Zhang,et,al. Deter-
mination of phase diagram of a ternary P-VDF/γ-BL/DOP system in TIPS process an-d its application in preparing hollow fiber membranes for membrane distillation[J]. Sep Purif Technol,2012,90:221-230.
[18] R Verma,H Marand,B Hsiao. Morpholo-gical Changes during Secondary Crystalliza-tion and Subsequent Melting in Poly(ether ether ketone) as Studied by Real Time Sm-all Angle X-ray Scattering[J]. Macromolecu-les,1996,29:7767-7775.
[19] Gregorio Jr. Determination of the α,β and γ crystalline phases of poly(vinylidene fluo-ride) films prepared at different conditions[J]. J Appl Polym Sci,2006,100:3272-3279.
[20] W M Prest Jr,Luca DJ. The morphology and thermal responseof higher temperature crystallized poly(vinylidene fluoride)[J].J A-ppl Phys,1975,46: 4136-4143.

服务与反馈:
文章下载】【加入收藏

《膜科学与技术》编辑部 地址:北京市朝阳区北三环东路19号蓝星大厦 邮政编码:100029 电话:010-64426130/64433466 传真:010-80485372邮箱:mkxyjs@163.com

京公网安备11011302000819号