选用不同种类的溶剂以L-S相转化法制备PVDF超滤膜,讨论了不同溶剂种类对膜结构和性能的影响.研究表明,仅仅考虑以热力学参数来预测或解释得到的最终膜结构和性能都是不充分的,必须考虑成膜的动力学过程.采用的4种溶剂所制备的PVDF超滤膜的纯水通量与相互扩散系数之间有很好的关联性,其通量顺序为DMSO>NMP>DMAC>DMF,即随着溶剂与水的相互扩散系数的增大,膜的纯水通量减小;膜的SEM照片显示,对PCDF膜而言,纯水通量不仅仅取决于皮层的孔隙率,也可被认为是亚层形态的显示.同时还采用了两种复合溶剂NMP/THF,NMP/AC制备PVDF超滤膜,考察了由于溶剂与水的亲合性变化而导致的膜性能和结构的变化,结果表明,随着溶剂中丙酮和四氢呋喃的浓度增加,复合溶剂与水的亲合性降低,膜的纯水通量下降,膜变得更加致密小孔,膜的SEM照片也证明了这点.
参考文献
[1] | Mulder M.膜技术基本原理[M].北京:清华大学出版社,1999 |
[2] | 高以;叶凌碧.膜分离技术基础[M].北京:科学出版社,1989 |
[3] | Strathmann H;Kock K .The formation mechanism of phase inversion membranes[J].DESALINATION,1977,21:241-255. |
[4] | Cohen C;Tanny G B;Prager S .Diffusion-controlled formation of porous structures in ternary polymer systems[J].J Polym Sci:Polym Phys Editn,1979,17:477-489. |
[5] | Smolders C A;Reuvers A J;Boom R M et al.Mierostructures in phase inversion membranes.Part 1,Formarion of macrovoids[J].J Membr Ssci,1992,73:259-275. |
[6] | Lau Y;Guever M D;Matsuura T .Phase separation in polysulfone/solvent/water and polyethersulfone/solvent/water systems[J].Journal of Membrane Science,1991,59:219-227. |
[7] | 沈飞 .不对称PVB超滤膜的制备研究及其在MBR中的应用[D].中国科学院上海应用物理研究所,2005. |
[8] | Bittino A;Camera-Roda G;Capannelli G et al.The formation of microporous polyvinylidene difluoride membranes by phase separation[J].Journal of Membrane Science,1991,57:1-20. |
[9] | Young T H;Chen L W .Roles of bimolecular interaction and relative diffusion rate in membrane structure control[J].Journal of Membrane Science,1993,83:153-166. |
[10] | Yilmaz L;Mchugh A J .Modelling of asymmetric membrane formation (Ⅰ) Critique of evaporation and development of a diffusion equation formalism for the quench period[J].Journal of Membrane Science,1986,28:287-310. |
[11] | Paul D R .Diffusion during the coagulation step of wetspinning[J].Journal of Applied Polymer Science,1968,12:383. |
[12] | Shieh JJ.;Chung TS. .Effect of liquid-liquid demixing on the membrane morphology, gas permeation, thermal and mechanical properties of cellulose acetate hollow fibers[J].Journal of Membrane Science,1998(1):67-79. |
[13] | W. Albrecht;Th. Weigel;M. Schossig-Tiedemann;K. Kneifel;K. - V. Peinemann;D. Paul .Formation of hollow fiber membranes from poly(ether imide) at wet phase inversion using binary mixtures of solvents for the preparation of the dope[J].Journal of Membrane Science,2001(1/2):217-230. |
[14] | Li ZS;Ren JZ;Fane AG;Li DF;Wong FS .Influence of solvent on the structure and performance of cellulose acetate membranes[J].Journal of Membrane Science,2006(1/2):601-607. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分:
-
10%
-
20%
-
30%
-
40%
-
50%