heterogeneous proton exchange membranes (pem) are synthesized using the dry phase inversion technique. the casting solutions are prepared by dispersing a finely ground cation exchange resin particle in n,n-dimethylacetamide (dmac) solution of polyvinyl-chloride (pvc). results show that ion exchange capacity is increased with the addition of 1 %-wt nanosilica (from 0.14 to 0.27 meq/g) while it i...

Wide-line 1H-NMR and differential scanning calorimetry measurements were done in aqueous solutions and on lyophilized samples of human ubiquitin between -70 degrees C and +45 degrees C. The measured properties (size, thermal evolution, and wide-line NMR spectra) of the protein-water interfacial region are substantially different in the double-distilled and buffered-water solutions of ubiquitin....

modified cellulose acetate (ca) membranes were prepared by dissolving the polymers in a mixture of acetone (ac) and n, n dimethylacetamide (dmac) (70:30) solvent and deionized (di) water was used in the coagulation bath. the introduction of polyethylene glycol (peg) additive and tio2 nanoparticles (nps) into the casting solution has changed the structures of the resulting membranes during the p...

In contrast to extensive studies on hydroxyapatite thin films, very little has been reported on the thin films of carbonated apatite (dahllite). In this report, we describe the synthesis and characterization of a highly crystalline dahllite thin film assembled via a biomimetic pathway. A free-standing continuous precursor film of carbonated calcium phosphate in an amorphous phase was first prep...

The requirements on a neutral current additive tc the heavy water in the SNO project are as follows: water solubility, low inherent radioactivity or the availability of an easy path of purification from thorium and radium, the possibility for easy separation from the water phase and safety. The solution of such an additive is expected to be transparent in the visible range, stable for extended ...

A molecular origin of the striking rate increase observed in a reaction on water is studied theoretically. A key aspect of the on-water rate phenomenon is the chemistry between water and reactants that occurs at an oil-water phase boundary. In particular, the structure of water at the oil-water interface of an oil emulsion, in which approximately one in every four interfacial water molecules ha...

Motivated by recent experiments showing the promise of noble gases as cryoprotectants, we perform molecular dynamics modeling of phase transitions in water with xenon under cooling. We follow the structure and dynamics of xenon water solution as a function of temperature. Homogeneous nucleation of clathrate hydrate phase is observed and characterized. As the temperature is further reduced we ob...

Surfactants are chemicals that adsorb to the interface between a solution and another phase (gases or solids) self-assemble molecular clusters known as micelles in (water oil phase). Measurements of surface tension sodium dodecyl sulfate (SDS) distilled water at 298.15K reported. The increase concentration then decreased 298.15K. Critical micelle (CMC) with decrease tension. graphs versus were ...

Water supply system is socially, politically, and financially critical, and long term security of water supply has to be met in spite of the huge uncertainty in its operation decades since the time of design. Everyone concerned with architecting such a system faces a common challenge: how do we design a system to perform well in a constantly evolving and thus risky context? As one of the water-...

A combined Monte Carlo and quantum mechanical study was carried out to analyze the tautomeric equilibrium of 2-mercaptopyrimidine in the gas phase and in aqueous solution. Second- and fourth-order Møller-Plesset perturbation theory calculations indicate that in the gas phase thiol (Pym-SH) is more stable than the thione (Pym-NH) by ca. 8 kcal/mol. In aqueous solution, thermodynamic perturbation...