Ionic transport through membranes

The two basic kinds of nickel—zinc main separators are the membranes and the microporous separators. Membrane separators are those in which ionic transport occurs through the interaction of the hydrophilic groups attached to the polymer with the ionic groups in the electrolyte. Ionic transport through mi-... 

So, since the conventional cationic exchange membranes suffer from higher S02 transport, CEA has built a test facility to characterise S02 transport through membranes. In collaboration with other laboratories, CEA is developing new membranes with reduced S02 transport characteristics and high ionic conductivity. 

ATPase activity was also studied by Friebe et al. in 1997.17 They correlated the BOA and DIBOA effects on radicle elongation of Avena sativa seedlings with their effects on the activity of plasma membrane H+-ATPase from roots of Avena sativa cv. Jumbo and from Vida faba cv. Alfred. They hypothesized that an alteration in the plasma membrane ATPase activity could be the reason for an abnormal nutrient absorption in plants exposed to hydroxamic acids, because of the role that this enzyme plays in the ion gradient and, therefore, in the ionic transport through plasma membrane. The results of this experiment showed a strong inhibition in the activity of this enzyme in the plasma membrane of chloroplast and mitochondria when it was exposed to BOA and DIMBOA. This alteration implies early interactions with the assayed hydroxamic acids. 

Grzywna, Z.J., Siwy, Z., and Bashford, C.L., Nonlinear theory for ionic transport through track-etched nuclear membranes. J. Membr. Sci., 1996, 121 261-269. 

Ion and Water Transport through Membranes. The quantitative interpretation of experiments on the influence of pulses is complicated by the fact that even in originally pure KC1 solutions, there are four ionic species in the polarization layers—viz., K+, Cl, H+, and OH . In natural waters the number of ionic species is still larger. Since there are no experimental methods to determine the... 

This experimental run was divided into two sections the first confirmed ionic transport through the membrane by removal of CO, (and HgO) fix>m the syngas at 625°C (Run 49A) and the second was an attempt at removal of HgS from the syn-gas at 700 C (Run 49C). The results of these studies are presented below ... 

D. Van Lamsweerde-Gallez and A. Meessen, The Role of Proteins in a Dipole Model for Steady-State Ionic Transport Through Biological Membranes, J. Membr. Biol. 23, 103-137 (1975). 

Reverse osmosis can be used for the separation of ions om an aqueous solution. Neutral membranes are mainly used for such processes and the transport of ions is determined by their solubility and diffusivity in the membrane (as expressed by the solute permeability coefficient, see eq V 162). The driving force for ion transport is the concentration difference, but if charged membranes or ion-exchange membranes are used instead of neutral membranes ion transport is also affected by the presence of the fixed charge. Teoreil [45] and Meyer and Sievers [46] have used a fixed charge theory to describe ionic transport through these type of systems. This theory is based on two principles the Nemst-Planck equation and Dorman equilibrium. 

Membrane cleaning by applying an ionic transport through the membrane (electrodialysis is best in this case). 

Ohmic loss is primarily due to the ionic transport through electrolyte membrane. Ohmic losses owing to the electron transfer through the electrode and intercoimect are neglected. 

Nednoor, P, Chopra, N, Gavalas, V, Bachas, LG and Hinds, BJ (2005), Reversible biochemical switching of ionic transport through ahgned carbon nanotube membranes , Chem Mater, 17(14), 3595-3599... 

In porous separators the pore radii are large compared to the size of molecules. Hence, interaction between the electrolyte and the pore walls has practically no qualitative effects on the ionic current through the separator the transport numbers of the individuaf ions have the same vafues in the pores as in the bulk electrolyte, hi swollen membranes the specific interaction between individuaf ions and macromofecufes is very pronounced. Hence, these membranes often exhibit sefectivity in the sense that different ions are affected differentfy in their migration. As a resuft, the transport numbers of the ions in the membrane differ from those in the efectrofyte outside the membrane. In the limiting case, certain types of ion are arrested completely, and the membrane is called permselective (see Chapter 5). 

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