Supercritical fluids have a unique and valuable potential for the enhanced processing of many materials. This review describes research in the applications of supercritical fluids to polymer processing. The ability of supercritical carbon dioxide to swell and plasticize polymers is crucial to the impregnation, extraction, and modification of polymeric materials. This plasticization also reduces...

Objective: The present research work is focused to develop in situ raft gel of lafutidine. Sodium alginate one the critical components for development system. Methods: formulation was prepared using hydrophilic polymers such as ethyl cellulose, HPMC K4M, and chitosan. formulations were subjected evaluation characteristics pH, vitro gelling time, viscosity, density, strength, drug-polymer compat...

Rheological studies were performed with aqueous salt solutions of viscoelastic cationic surfactant erucyl bis(hydroxyethyl)methylammonium chloride (EHAC) and its mixtures with hydrophobically modified polyacrylamide. The solutions of surfactant itself above the concentration of crossover of wormlike micelles exhibit two regions of rheological response. In the first region, they behave like poly...

A robust and precise viscometer using the forces exerted by a laminar flow inside a small duct is presented: the force is measured on a long cylindrical sensor dipped into the flow. Two devices of respective volumes 1.4 and 0.031 ml have been realized, demonstrating that the technique is usable with small fluid volumes. Several Newtonian and non-Newtonian fluids have been tested at shear rates ...

A model is developed that describes temperature and pressure dependence of dielectric relaxation, ionic conductivity, and viscosity of glass-forming liquids near the glass transition temperature. The expressions for ionic conductivity are compared with experimental results for two polymer electrolytes. Those for dielectric relaxation are compared with data for poly(propylene oxide) and poly(vin...

Using a programmable mixing pump, light scattering flow chamber, refractive index detector, and single capillary viscometer, the batch (unfractionated) characterization of polymers in solution has been automated. Three different schemes to produce polymer concentration gradients were used, and values for weight average mass Mw, root mean square radius of gyration ^S & , second virial coefficien...

We examined whether hemorheology and platelet function are affected in essential hypertensives (EHTs) of the World Health Organization stage I when complicated with metabolic syndrome (Mets). In 156 untreated EHTs, blood viscosity and platelet surface markers were determined. Blood viscosity was significantly elevated in 54 subjects with Mets compared with 102 subjects without Mets. Hematocrit ...

The dynamics of glass is of importance in materials science but its nature has not yet been fully understood. Here we report that a verification of the temperature dependencies of the primary relaxation time or viscosity in the ultraslowing/ultraviscous domain of glass-forming systems can be carried out via the analysis of the inverse of the Dyre-Olsen temperature index. The subsequent analysis...

The dissolution of hyaluronan in water leads to its degradation, and as a result its molecular weight decreases. The degradation of hyaluronan is mainly influenced by temperature, solution composition, and also its pH. This study describes the influence of Hofmeister series ions on hyaluronan behaviour and hyaluronan film swelling by solutions of these ions. It was found that Hofmeister ions sh...