Romero Virginia, Vega Victor, García Javier, Prida Victor M, Hernando Blanca, Benavente Juana
Applied Physics Department I, Faculty of Sciences, University of Malaga, E-29071 Málaga, Spain.
Physics Department, Faculty of Sciences, University of Oviedo, E-33007 Oviedo, Spain.
Nanomaterials (Basel). 2014 Aug 6;4(3):700-711. doi: 10.3390/nano4030700.
Diffusive transport through nanoporous alumina membranes (NPAMs) produced by the two-step anodization method, with similar pore size but different porosity, is studied by analyzing membrane potential measured with NaCl solutions at different concentrations. Donnan exclusion of co-ions at the solution/membrane interface seem to exert a certain control on the diffusive transport of ions through NPAMs with low porosity, which might be reduced by coating the membrane surface with appropriated materials, as it is the case of SiO₂. Our results also show the effect of concentration polarization at the membrane surface on ionic transport numbers (or diffusion coefficients) for low-porosity and high electrolyte affinity membranes, which could mask values of those characteristic electrochemical parameters.
通过两步阳极氧化法制备的具有相似孔径但孔隙率不同的纳米多孔氧化铝膜（NPAMs），利用不同浓度NaCl溶液测量的膜电位进行分析，研究其扩散传输。溶液/膜界面处共离子的唐南排斥似乎对低孔隙率NPAMs中离子的扩散传输有一定控制作用，通过用适当材料（如SiO₂）涂覆膜表面，这种控制作用可能会降低。我们的结果还表明，对于低孔隙率和高电解质亲和力的膜，膜表面的浓差极化对离子迁移数（或扩散系数）有影响，这可能会掩盖那些特征电化学参数的值。
