Membrane transport of the non-homogeneous ternary solutions: mathematical model of thicknesses of the concentration boundary layers.

We have presented the mathematical model, which can be the basis of determination of a numerical algorithm for the thickness of concentration boundary layers calculation for ternary nonelectrolyte solutions. This model is based on Rayleigh equation and second Kedem-Katchalsky equation for ternary solutions. In proposed model, the thickness of concentration boundary layers is controlled by concentration Rayleigh number.

[Computer modeling the concentration characteristics of the membrane potential for polymeric membrane, separated non-homogeneous electrolyte solutions]. / Modelowanie komputerowe charakterystyk stezeniowych potencjalu membranowego generowanego na membranie polimerowej, rozdzielajacej niejednorodne roztwory elektrolityczne.

The influence of the concentration boundary layers on membrane potential (deltapsis) in a single-membrane system on basis of the Kedem-Katchalsky equations was described in cases of horizontally mounted neutral polymeric membrane separates non-homogeneous (mechanically unstirred) binary electrolytic solutions at different concentrations. Results of calculations of deltapsis as a function of ratio solution concentrations (Ch/Cl) at constant values of: concentration Rayleigh number (Rc), concentration polarization coefficient (zetas) and hydrostatic pressure (deltaP) were presented. Calculations were made for the case where on a one side of the membrane aqueous solution of NaCl at steady concentration 10(-3) mol x l(-1) (Cl) was placed and on the other aqueous solutions of NaCl at concentrations from 10(-3) mol x l(-1) to 2 x 10(-2) mol x l(-1) (Ch). Their densities were greater than NaCl solution's at 10(-3) mol x l(-1). It was shown that membrane potential depends on hydrodynamic state of a complex concentration boundary layer-membrane-concentration boundary layer, what is controlled by deltaP, Ch/Cl, Rc and zetas.

[Computer modeling the hydrostatic pressure characteristics of the membrane potential for polymeric membrane, separated non-homogeneous electrolyte solutions]. / Modelowanie komputerowe charakterystyk cisnieniowych potencjalu membranowego generowanego na membranie polimerowej, rozdzielajacej niejednorodne roztwory elektrolityczne.

On the basis of model equation depending the membrane potential deltapsis, on mechanical pressure difference (deltaP), concentration polarization coefficient (zetas), concentration Rayleigh number (RC) and ratio concentration of solutions separated by membrane (Ch/Cl), the characteristics deltapsis = f(deltaP)zetas,RC,Ch/Cl for steady values of zetas, RC and Ch/Cl in single-membrane system were calculated. In this system neutral and isotropic polymeric membrane oriented in horizontal plane, the non-homogeneous binary electrolytic solutions of various concentrations were separated. Nonhomogeneity of solutions is results from creations of the concentration boundary layers on both sides of the membrane. Calculations were made for the case where on a one side of the membrane aqueous solution of NaCl at steady concentration 10(-3) mol x l(-1) (Cl) was placed and on the other aqueous solutions of NaCl at concentrations from 10(-3) mol x l(-1) to 2 x 10(-2) mol x l(-1) (Ch). Their densities were greater than NaCl solution's at 10(-3) mol x l(-1). It was shown that membrane potential depends on hydrodynamic state of a complex concentration boundary layer-membrane-concentration boundary layer, what is controlled by deltaP, Ch/Cl, RC and zetas.

[Study on the volume flows through polymeric membranous dressing with silver ions]. / Badanie przeplywów objetosciowych przez polimerowy opatrunek membranowy z jonami srebra.

The volume flows through double-layer polymeric membranous dressing, formed by three types of theromoplastic polymeric fibers called Textus Bioactive were studied. The first layer contains two types of fibers: the polymeric fibers containing hydrophobic core and hydrophilic surfaces with silver zeolite and hydrophilic super absorbing polymers (SAP). The second layer of membrane contains third type of polymeric fibers, arranged parallel to surface's skin, creating a net, which prevents membranous dressing from sticking to treated wound. The pressure characteristics of the volume flux were determined and it was stated that the value of this flux is dependent on the value of hydrostatic pressure difference (deltaP) and the concentration difference (deltaC) of solutions separated by membrane. Experimental results show that the membranous dressing Textus Bioactive posses the rectifying properties with reference to volume flows. These properties occurs above a threshold value of deltaC. Using the Kedem-Katchalsky equations, the model of the volume flows through membranous dressing Textus Bioactive was made.

[Computer modeling the dependences of the membrane potential for polymeric membrane separated non-homogeneous electrolyte solutions on concentration Rayleigh number]. / Modelowanie komputerowe zaleinosci potencjalu membranowego generowanego na membranie polimerowej, rozdzielajacej niejednorodne roztwory elektrolityczne od stezeniowej liczby Rayleigha.

On the basis of model equation describing the membrane potential delta psi(s) on concentration Rayleigh number (R(C)), mechanical pressure difference (deltaP), concentration polarization coefficient (zeta s) and ratio concentration of solutions separated by membrane (Ch/Cl), the characteristics delta psi(s) = f(Rc)(delta P, zeta s, Ch/Cl) for steady values of zeta s, R(C) and Ch/Cl in single-membrane system were calculated. In this system neutral and isotropic polymeric membrane oriented in horizontal plane, the non-homogeneous binary electrolytic solutions of various concentrations were separated. Nonhomogeneity of solutions is results from creations of the concentration boundary layers on both sides of the membrane. Calculations were made for the case where on a one side of the membrane aqueous solution of NaCl at steady concentration 10(-3) mol x l(-1) (Cl) was placed and on the other aqueous solutions of NaCl at concentrations from 10(-3) mol x l(-1) to 2 x 10(-2) mol x l(-1) (Ch). Their densities were greater than NaCl solution's at 10(-3) mol x l(-1). It was shown that membrane potential depends on hydrodynamic state of a complex concentration boundary layer-membrane-concentration boundary layer, what is controlled by deltaP, Ch/Cl, Rc and Zeta(s).

[Study of transport properties of the polymeric membranous dressing with silver ions]. / Badanie wlasciwosci transportowych polimerowego opatrunku membranowego z jonami srebra.

The transport properties of polymeric membraneous dresing silver ion containing Textus Bioactive were studied. This dressing is made of three types of theromoplastic polymeric fibers, formed into two-layers membrane. In first layer occure the polymeric fiber, which the core is hydrophobic and hydrophilic surfaces contain a silver zeolite. These fibers neighborours with hydrophilic super absorbing polymers. Third type of polymeric fibers occur in the second layer of membrane and is arranged parallel to surface's skin, creating a net preventing stick of membraneous dressing to treated wound. Using of the Kedem-Katchalsky equations the transport model of this membrane and the temporal and concentration characteristics of transport parameters (hydraulic permeability, refection and solute permeability) were determined. Experimental results show that the polymeric membranous dressing contain the silver ions posses non-linear transport properties, which are consequence of structure and physicochemical properties of polymeric membranes.