Adsorption of anionic surface active substances (SAS) on charged membranes Original Research Article

We investigated the adsorption of aqueous solutions of sodium dodecylsulphate (NaDS) on poly-amide membranes of different composition. Experimental membranes PA- 100(+) were a mixture of polyphenyl-phtlAmide and copolymer of acrylonitrile with dinaethyl diallyl ammonium chloride (60:40) and PA-100(-). These were based on the product of copolycondensation of sodium salt of 4, 4′-diamindiphenilmnine-2-sulplwnic acid (8 mol.%) and m-pheny iamine with isophthaloyl chloride with pore sizes 5.7–9.0 nni and a small surface charge. Also used was a PA-10 membrane of poly-phenileisophthslamide with a pore radius of 2.9 to 5.8 mm It was shown that nurximurn adsorption on the PA-10 was determined mainly by the electrostatic interaction of NaDS with the PA-10 surface. Analysis of the adsorption mechanism on PA-100(+) and PA-100(−) showed that the adsorption layer structure determining the characteristics of the membranes for these ntcmbranes was effectively different, which was confirmed by the data on desorption of NaDS by water from the membrane surface.