Giorno L, Mazzei R, Oriolo M, De Luca G, Davoli M, Drioli E
Institute on Membrane Technology, CNR-ITM, University of Calabria, Via P. Bucci 17/C, 87036 Rende (CS), Italy.
J Colloid Interface Sci. 2005 Jul 15;287(2):612-23. doi: 10.1016/j.jcis.2005.02.015.
Hydrophilic ultrafiltration membranes made of polyamide with molecular weight cutoff 10 and 50 kDa have been studied for the preparation of oil-in-water emulsions by a cross-flow membrane emulsification technique. Isooctane and phosphate buffer were used as disperse and continuous phase, respectively. The permeation of apolar isooctane through the polar hydrophilic membrane was achieved by pretreatment of membranes with a gradient of miscible solvents of decreasing polarity to remove water from the pores and replace it with isooctane. Four different procedures were investigated, based on the solvent mixture percentage and contact time with membranes. After pretreatment, the performance of the membranes in terms of pure isooctane permeate flux and emulsion preparation was evaluated. The influence of organic solvents on polyamide (PA) membranes has been studied by SEM analysis, which showed a clear change in the structure and morphology of the thin selective layers. The effects proved stronger for PA 10 kDa than for 50 kDa. In fact, similar pretreatment procedures caused larger pore size and pore size distribution for PA 10 kDa than for 50 kDa. The properties of emulsions in terms of droplet size distribution reflected the membrane pore sizes obtained after pretreatment. The correlation between pore size and droplet size, for the physicochemical and fluid dynamic conditions used, has been evaluated.
已对截留分子量为10 kDa和50 kDa的聚酰胺制成的亲水性超滤膜进行了研究，以通过错流膜乳化技术制备水包油乳液。异辛烷和磷酸盐缓冲液分别用作分散相和连续相。通过用极性递减的互溶溶剂梯度对膜进行预处理，以从孔中除去水并用异辛烷代替，从而实现非极性异辛烷透过极性亲水性膜。基于溶剂混合物百分比和与膜的接触时间，研究了四种不同的程序。预处理后，评估了膜在纯异辛烷渗透通量和乳液制备方面的性能。通过扫描电子显微镜（SEM）分析研究了有机溶剂对聚酰胺（PA）膜的影响，结果表明选择性薄层的结构和形态发生了明显变化。事实证明，PA 10 kDa所受影响比50 kDa更强。实际上，类似的预处理程序使PA 10 kDa的孔径和孔径分布比50 kDa更大。乳液在液滴尺寸分布方面的性质反映了预处理后获得的膜孔径。对于所使用的物理化学和流体动力学条件，已评估了孔径与液滴尺寸之间的相关性。
