a difference in salt concentration in two solutions separated by a membrane leads to an electrical potential difference across the membrane, also without applied current. a literature study is presented on proposed theories for the origin of this membrane potential (ϕm). the most well-known theoretical description is teorell-meyer-sievers (tms) theory, which we analyze and extend. experimental ...

the suitability of three vapor deposition techniques for pore size modification was evaluated using polycarbonate track etched membranes as model supports. a feature scale model was employed to predict the pore geometry after modification and the resulting pure water flux. physical vapor deposition (pvd) and pulsed plasma-enhanced chemical vapor deposition (pecvd), naturally, form asymmetric na...

in this study, polystyrene ethylene butylene polystyrene (psebs) was functionalized to prepare mono and bipolar ion exchange membranes. in the case of the bipolar membrane, platinum was used as the intermediate layer. nacl solution of concentration ranging from 5 g/l to 25 g/l was used as the feed solution. a commercially procured ion exchange membrane made of polystyrene divinyl benzene was al...

polyvinylidene fluoride/polyvinylpyrrolidone (pvdf/pvp) hollow fiber membranes were fabricated by dry-jet wet-spinning process. the correlated effects of the air gap length and pvp concentration ((1) the air gap length effect at the low and high pvp concentration in the dope solutions, as well as (2) the effect of the pvp concentration at the same air gap length) on the cross-section structure ...

Nowadays, proton exchange membrane fuel cells (PEMFCs) are the most promising green energy conversion devices for portable and stationary applications. Traditionally, these devices were based onperfluoro-sulfonic acid electrolytes membranes, given the commercial name Nafion. Nafion is the mostused electrolyte membrane till now; because of its high electrochemical properties su...

in this article, the immobilization of microsomal membranes on fractosil and hexadecylfractosil by hydrophobic adsorption is reported. microsomes were prepared from rat brain and thecatalytic activity of antimycin a insensitive nadh-cytochrome c reductase (nccr), one of themembrane bound enzymes in the microsomal electron transport chain, was chosen as a representative ofthe microsomal membrane...

Polyacrylonitril (PAN)-supported chitosan (CS) nanocomposite membranes were prepared by cross-linking the CS with 3-aminopropyl-triethoxysilane (APTEOS) via sol-gel method. Pervaporative performances of the CS-SiO2/PAN membrane for dehydration of aqueous alcohol solutions were investigated. From SEM cross-sectional images of the membrane, the spongy pores and the finger-like pores we...

Optically active bionanocomposite membranes composed of polyester(PE) and cellulose /silica bionanocomposite (BNCs) are a novel method to enhance gas separation performance. Commercially available silica nanoparticles were modified with biodegradable nanocellulose through ultrasonic irradiation technique. Transmission electron microscopy (TEM) analyses showed that the cellulose/silica composite...

In the present work, two asymmetric polymer membranes based on polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP) with chitin and chitosan (as extractive agents) were synthesized through the phase inversion technique. The mechanisms of oriented process for the facilitated extraction of blue P3R dye across the as-prepared membranes were elucidated through different experiments. Furthe...

In this work the conduction of ion-water solution through two discrete bundles of armchair carbon and silicon carbide nanotubes, as useful membranes for water desalination, is studied. In order that studies on different types of nanotubes be comparable, the chiral vectors of C and Si-C nanotubes are selected as (7,7) and (5,5), respectively, so that    a similar volume of fluid is investigated ...