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1

Evaluation of transport properties of biomembranes by means of Peusner network thermodynamics

Batko Kornelia M., Ślęzak Andrzej, Pilis Wiesław

Acta of Bioengineering and Biomechanics

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2021

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Vol. 23, no. 2

63--72

EN

Purpose: The R version of the Kedem–Katchalsky–Peusner (KKP) network equations is one of the basic research tools for membrane transport. For binary solutions of non-electrolytes containing a solvent and one solute, these equations include the Peusner resistance coefficients. The aim of the study was to assess the transport properties of biomembranes on the basis of the concentration characteristics of the coefficients: resistance, coupling, energy conversion efficiency and degraded and free energy fluxes. Methods: The subject of the study were polymer biomembranes used as a membrane dressing (Bioprocess) and used in hemodialysis (Nephrophan, Ultra-flo) with the coefficients of hydraulic permeability (Lp), reflection (σ) and diffusion permeability (ω) for aqueous glucose solutions. The research method was the R version of the KKP network equations for binary solutions of non-electrolytes. Results: We developed a procedure for evaluation the transport properties of membranes. This procedure requires the calculation of the dependence of the following coefficients: Peusner resistance, Kedem–Caplan–Peusner coupling, Caplan–Peusner energy conversion efficiency, Peusner coupling, and the dissipated energy and free energy fluxes on the mean glucose concentration. Results show that the values of the Peusner resistance coefficients, the Kedem–Caplan–Peusner coupling, the Caplan–Peusner energy conversion efficiency, and the Peusner coupling depend on the mutual relationship between the coefficients Lp, σ, ω and C. In turn, the value of the dissipated energy and free energy fluxes it is also determined by the values of the volume and diffusion fluxes. Conclusions: The presented procedure for evaluation transport properties of membranes can be helpful in explaining the mechanisms of membrane transport and conducting energy analyzes of membrane processes. Therefore, this procedure can be used for selection of a suitable membrane for practical (eg., industrial or medical) applications.

2

Impact of solute exchange between erythrocytes and plasma on hemodialyzer clearance

Waniewski J., Poleszczuk J., Pietribiasi M., Debowska M., Wojcik-Zaluska A., Zaluska W.

Biocybernetics and Biomedical Engineering

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2020

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Vol. 40, no. 1

265--276

EN

The standard theory of mass transport in dialyzer for water solutions was extended for solutes distributed in both plasma (PW) and erythrocyte intracellular (EW) water. Blood flow was divided into two separate flows of PW and EW with the diffusive exchange of solutes across cellular membrane (CM). Diffusive permeability of CM for urea and creatinine were assumed according to literature data. Computer simulations based on partial differential equations demonstrated that urea diffuses fast across CM and can be approximately considered as distributed uniformly in both blood flow components. In contrast, creatinine can be considered as distributed only in PW flow during the passage along the dialyzer. Therefore, the traditional formula for dialyzer clearance can be applied for urea and creatinine with the adjustment of their effective ‘‘blood’’ flow, but not for solutes with intermediate molecular mass. In vivo clearances of urea and creatinine were, as expected, lower than the respective theoretical predictions based of the diffusive permeability, P, times membrane surface area, A, parameters, PA, for dialyzer membrane, estimated for water solutions, by 33.6 ± 10.9% for creatinine and 10.8 ± 9.4% for urea. The estimated in vivo PAs were for creatinine 65.4 ± 26.0% and for urea 32.0 ± 10.9% lower than in vitro values provided by manufacturers. The much higher drop in clinical clearance/PA for creatinine than for urea suggests that the exchange of creatinine between plasma and dialysis fluid needs to be adjusted for the reduction of the dialyzer membrane surface area, which is effectively available for creatinine, caused by the presence of erythrocytes.

3

Characteristics of polymeric ultrafiltration membranes produced with the use of graphene oxide

Tomczak E., Blus M.

Ecological Chemistry and Engineering. S

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2018

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Vol. 25, nr 3

419--429

EN

This article describes a method for producing polymeric membranes by adding carbon nanostructures in the form of graphene oxide (GO). The reference membrane (having typical composition) was formed via phase inversion, using polyvinylidene fluoride (PVDF) dissolved in dimethylacetamide (DMAC). The polymeric matrix was additionally enriched with a plasticizer, i.e. polyethylene glycol (PEG). Afterwards, graphene oxide ultrasonically dispersed in dimethylacetamide was added to basic matrix. The membranes were further compared with one another by measuring their contact angle and hydrodynamics. The results were compared with the literature reports. The transport properties of the membranes were assessed with experimental ultrafiltration equipment (KOCH Membrane System). Also, their permeate flux and mass transfer resistance were determined.

4

Model equation of relative solute permeability coefficient of membrane-concentration boundary layers complex

Bryll A., Michalska-Małecka K., Grzegorczyn S., Ślęzak A.

Polimery

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2009

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T. 54, nr 9

662-667

EN

Considering non-homogeneity of non-electrolyte solutions, the membrane transport is different than the transport of homogeneous solutions described by Kedem-Katchalsky equations, as a result of the concentration polarization phenomenon and concentration boundary layers formed up near the membrane. These layers have a significant influence on the volume and solution flows. The model equation for the relative permeability coefficient ?s of the system: the membrane and concentration boundary layers is presented, and dependence of this coefficient on the solution concentration, concentration Rayleigh number, and gravity acceleration is studied. The experimental tests were performed by a chamber system method in the membrane system with the membrane mounted horizontally. The test results show a good compliance with theoretical calculations and indicate that the relative solute permeability coefficient of the membrane-concentration boundary layers system decreases in time and seems to be independent on the initial concentration of the solution.

PL

Szerokie zastosowanie membran polimerowych w technologii i naukach medycznych, niesie ze sobą konieczność ich szczegółowego badania pod kątem właściwości transportowych. Ze względu na niejednorodność roztworów nieelektrolitów, ich transport membranowy różni się od transportu roztworów jednorodnych (opisanych równaniami Kedem-Katchalsky'ego) na skutek zjawiska polaryzacji stężeniowej i tworzenia się przy membranie stężeniowych warstw granicznych. Warstwy te mają znaczący wpływ na przepływy objętościowe i przepływy solutu. Przedstawiono model opisujący względny współczynnik przepuszczalności (?s) w układzie membrana-stężeniowe warstwy graniczne oraz zbadano zależności tego współczynnika od stężenia roztworu, stężeniowej liczby Rayleigha i przyspieszenia grawitacyjnego. Poprawność modelu zbadano eksperymentalnie używając poziomo ustawionej membrany (Nephrophan wykorzystywanej w hemodializerze zwojowym) rozdzielającej przestrzenie układu membranowego. Wyniki badań są zgodne z obliczeniami teoretycznymi i wskazują, że względny współczynnik przepuszczalności solutu w układzie membrana-stężeniowe warstwy graniczne zmniejsza się w czasie i wydaje się być niezależny od początkowego stężenia roztworu.

5

Studies on Transport of Pb(II) Ions Using Different Crown Ethers

Ashraf W., Fazal A.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 6

881-887

EN

Membrane based separation processes represent a sophisticated way to limit industrial wastes in the natural environment. Crown ethers have been recognized as very effective class of compounds to achieve selective separation of heavy metal ions from aqueous solutions. Lead (Pb) is a well known toxic metal and is heavily used in industry. Therefore, finding ways to selectively remove Pb(II) from aqueous solutions is important. In the present paper, different crown ethers of varying cavity size, subsituent groups, donor atoms, and ring number are compared for their ability to transport Pb2+ through a supported liquid membrane. All experiments were carried out in a laboratory scale membrane reactor with crown ether solution immobilized on a polypropylene porous sheet interposed between feed and strip solutions. It was observed that when O atoms of the same sized macrocycle are replaced with N or S atoms, percentage recovery of Pb(II) increases significantly. By substituting a benzene ring on the same sized macrocycle, the percentage of Pb(II) transport increased from 78 to 86%. The cavity size of the crown ether seems to affect the rate of transport. After different trials, it was found that transport is maximal where the ionic radius of Pb(II) matches maximum with the cavity diameter of the macrocycle. These interactions of crown ethers with Pb(II) are explained on the basis of metal-ligand coordination chemistry.

6

Ciśnieniowy efekt stężeniowych warstw granicznych w jednomembranowej komórce osmotyczno-dyfuzyjnej

Ślęzak A., Wąsik J.

Prace Naukowe. Chemia / Wyższa Szkoła Pedagogiczna w Częstochowie

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2003

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Vol. 8

121--134

PL

Przedstawiono klasyfikację i definicje efektów stężeniowych warstw granicznych w biernym transporcie membranowym. Wyróżniono strumieniowe (strumieniowy efekt stężeniowych warstw granicznych, strumieniowy efekt grawidyfuzyjny, prądowy efekt grawielektryczny) i bodźcowe (ciśnieniowy efekt grawiosmotyczny, ciśnieniowy efekt grawidyfuzyjny, napięciowy efekt grawielektryczny) efekty grawitacyjne. Opracowano matematyczny model ciśnieniowego efektu stężeniowych warstw granicznych w 1-membranowej komórce osmotyczno-dyfuzyjnej zawierającej ustawioną poziomo płaską, mikroporowatą i symetryczną membranę polimerową (Nephrophane) rozdzielającą wodę i dwuskładnikowe (wodne roztwory glukozy) lub trójskładnikowe (roztwory glukozy w 0.2 mol.l-1 wodnym roztworze etanolu) roztwory nieelektrolitów. Obliczenia ciśnieniowego efektu stężeniowych warstw granicznych wykonano dla dwu konfiguracji (A i B) 1-membranowej komórki osmotyczno-dyfuzyjnej. W konfiguracji A roztwór znajdował się pod membraną, natomiast w konfiguracji B - nad membraną. Ponadto zdefiniowano i obliczono ciśnieniowy efekt grawiosmotyczny. Otrzymane rezultaty obliczeń zinterpretowano w kategoriach konwekcyjnej niestabilności, zwiększającej wartość współczynnika przepuszczalności dyfuzyjnej układu: warstwa graniczna/membrana/warstwa graniczna.

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Transport studies of inorganic and organic cations across liquid membranes containing Mannich-base calix[4]resorcinarenes

Pietraszkiewicz O., Kozbiał M., Pietraszkiewicz M.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 5

886-892

EN

Three calix[4]resorcinarenes, two of them incorporating Mannich-type amino functions (C2 and C3), have been studied in respect to their ionoselectivities towards inorganic alkali cations as well as for organic primary ammonium cations, by ion transport across the bulk liquid membrane and extraction experiments. The ligand C3 displayed particular ionoselectivity for lithium ion, as a carrier in toluene membrane. The discrimination of organic primary ammonium ions was remarkable in liquid membranes, and the pattern of this discrimination depended on the membrane composition. Selectivities for both inorganic and organic ions depended significantly on the membane composition, the substituent in the calix[4]resorcinarene, and the counterion present in the salts studied.