Electrotransport properties and morphology of MF-4SK membranes after surface modification with polyaniline

Studies of asymmetry of diffusion permeability of nanocomposite ion-exchange membranes: Model of charge density of fixed groups linear by membrane thickness

“…However, comparison of the thickness of modified layers [3][4][5][6] obtained from optical measurements [1] and calcu lated according to the method suggested in [2] allowed making an important conclusion as to the nonuniform distribution of charges of fixed groups in the synthe sized nanocomposite MF 4SK/PANI membranes, i.e., presence of a gradient of these charges across the membrane depth. The study of surface morphology of synthesized composite membranes using the method of scanning electron microscopy [7] confirmed the assumption as to penetration of PANI chains to the membrane side opposite to the modifying solution even after 1 h modification. Earlier, we used as the "zero" approach the model of a bilayer membrane with opposite layer charges and it did itself justice in the case of thin-layer modification.…”

“…Experimental data on diffusion permeability of MF 4SK membranes modified on one side by PANI for 1, 2, and 3 h were obtained in Kuban State Univer sity [2,7]. We used them to test the adequacy of the model of linear density of fixed membrane charges sug gested here.…”

“…Thus, solutions of equations (23) or (23') can be used to find other diffusion permeability P s = ϑ s D. Then asymmetry coefficient of diffusion permeability, same as earlier in [1][2][3][4][5][6][7], is equal to the ratio of (24)…”

“…An aqueous hydrochloric acid solution of different concentrations was used as electrolyte. Full description of the experimental technique is given, e.g., in [7]. As only four parameters are used in the new model, ρ 1 , ρ 2 , γ, and D, the following optimization problem was to be solved for comparison of theoretical and experimental data for each modification time:…”

Surface modification of PTMSP membranes by plasma treatment: Asymmetry of transport in organic solvent nanofiltration

“…Later, the effect of asymmetry was also observed for some other systems, including the bilayered charged membranes, and the membranes modified by the hydrated zirconium oxide and polyaniline [2,15,16,[19][20][21][22][23]. Fascinating results were obtained for the transport asymmetry in the model systems based on the track-etched membranes.…”