Determining the Dielectric Constant inside Pores of Nanofiltration Membranes from Membrane Potential Measurements

作者：Escoda Aurelie; Lanteri Yannick; Fievet Patrick^*; Deon Sebastien; Szymczyk Anthony

来源：Langmuir, 2010, 26(18): 14628-14635.

DOI：10.1021/la1023949

The membrane potential technique was applied to a nanofiltration polyamide membrane to determine its mean pore radius and the dielectric constant of electrolyte solutions inside pores To our knowledge, this is the first attempt to assess these features from membrane potential measurements Membrane potential data were analyzed by means of the SEDE (stem: electric and dielectric exclusion) transport model Experiments were conducted with single-salt solutions of NaCl and CaCl2 and mixed-salt solutions of NaCl and CaCl2 at various concentrations It was shown that the pore-size values deduced from the high-concentration limit of the membrane potential measured with the two single-salt solutions are in good agreement With this parameter being known, the membrane potential measured at high salt concentration with electrolyte mixtures was further used to compute the dielectric constant inside pores The latter was found to be smaller than its bulk value and to decrease when sodium ions were replaced by calcium ions

• 出版日期2010-9-21