Polymer wrapped single walled carbon nanotubes (SWNTs) have been synthesized to improve the solubility of SWNTs in water. The present study deals with experiments so as to highlight the solute solvent interactions during the solubilisation of polyvinyl pyrrolidone wrapped single walled carbon nanotubes (PVP-SWNTs) in water by viscometric methods. Viscosity values of both PVP and PVP-SWNTs have ...

piroxicam (px), an anti-inflammatory drug, exhibits poor water solubility, dissolution and flow properties. thus, the aim of the present study was to improve the solubility and dissolution rate of px by freeze drying technique using dimethylformamide (dmf), chloroform and water as co-solvent system. the prepared crystals containing px were evaluated for dmf and chloroform solvent residual by ga...

The enthalpically favoured hydration of hydrophobic entities, termed hydrophobic hydration, impacts the phase behaviour of numerous amphiphiles in water. Here, we show experimental evidence that hydrophobic hydration is strongly determined by the mean energetics of the aqueous medium. We investigate the aggregation and collapse of an amphiphilic polymer, poly-N-isopropyl acrylamide (PNiPAM), in...

Several commercial polymeric ultrafiltration membranes were screened for their performance with aqueous ethanol solutions. The method of conditioning the membrane has a major effect on solvent flux, membrane integrity and their pressure ratings. Gradual solvent exchange with successively higher concentrations increased in small doses appears to work best with completely miscible solvents such a...

Using NPT and NVT molecular dynamics simulation techniques, we have simulated an atomistic model of solvated Nafion in the lithium salt form, with the following three main objectives: (i) to obtain details on the local environment of the lithium cations and to assess the solvent effect on their binding, (ii) to investigate the translational and rotational motion of solvent molecules (water and ...

Enzyme catalysis evolved in an aqueous environment. The influence of solvent dynamics on catalysis is, however, currently poorly understood and usually neglected. The study of water dynamics in enzymes and the associated thermodynamical consequences is highly complex and has involved computer simulations, nuclear magnetic resonance (NMR) experiments, and calorimetry. Water tunnels that connect ...

Using analytical second derivatives of the generalized conductorlike screening model ~GCOSMO! we calculate vibrational frequency shifts for several molecules ~acetone, methylamine, formic acid, acetic acid, and trans-NMA! solvated in water. In these calculations, results from dielectric continuum approach with and without several explicit water molecules are compared with traditional supermolec...

Results on thermodiffusion of poly~ethylene oxide! and colloidal boehmite (g-AlOOH! rods in ethanol/water mixtures are presented. Data were obtained using thermal diffusion forced Rayleigh scattering. The sign of the Soret coefficient of the boehmite rods changes from positive to negative with increasing water content, i.e., at sufficiently high water content the colloidal particles move to hig...

To investigate the structural and thermodynamic basis of the binding of solvent at internal sites within proteins a number of mutations were constructed in T4 lysozyme. Some of these were designed to introduce new solvent-binding sites. Others were intended to displace solvent from preexisting sites. In one case Val-149 was replaced with alanine, serine, cysteine, threonine, isoleucine, and gly...

Using concentrated nitric acid as the solvent, and water as the non-solvent, one-dimensional (1D) organic nanowires can be synthesized in a simple, one-pot process with high yield. The method has broad validity to a wide range of aromatic molecules for the synthesis of derivatized organic wires.