the purpose of this study was to prepare and characterize nimodipine loaded microspheres using ethyl cellulose (ec) as a carrier polymer through an emulsion solvent evaporation method. these evaluations characterized the pattern of drug release from prepared microspheres. nimodipin loaded microspheres were prepared using an emulsification solvent evaporation method. the effect of process variab...

Due to the importance of nanoparticles stability in industrial applications, in this research, stability of laponite nanoparticles dispersions containing different concentrations of sodium sulfonated polyacrylamide (SPA) was investigated in electrolyte media for oil reservoirs applications. In this regard, effect of parameters such as polymer concentration, temperature, and ionic strength were ...

For ternary polymer-salt-water systems at low polymer concentration (0.5%, w/w), we have experimentally investigated the effect of polymer size on polymer diffusiophoresis (i.e., polymer migration induced by a salt concentration gradient) and salt osmotic diffusion (i.e., salt migration induced by a polymer concentration gradient). Specifically, Rayleigh interferometry was employed to measure t...

The authors investigated the polymer-mediated colloidal interactions in a good solvent wherein the particle size varies from that much smaller than the polymer radius of gyration up to macroscopic and the polymer concentration varies from that corresponding to a dilute solution to that close to a melt. At conditions directly accessible to molecular simulations, the theoretical predictions agree...

Based on Gibbs-Duhem law and using UNIFAC-FV computer algorithm, the activity of polymer component in polymer-solvent systems is determined. The variation of activity of components with concentration at different temperatures are used to find the equilibrium concentration, UCST, and LCST for the systems. Also by generalization of the method, Gel-Liquid equilibrium is studied in some three c...

Excessive water production through fractures become an important problem in oil exploration of fractured reservoirs. For this purpose, polymer gels were prepared by crosslinking of aqueous solutions of polymer and crosslinker for the purpose of water management in high water cut fractured reservoirs. A copolymer of sulfonated polyacrylamide was used as polymer and chromium triacetate (Cr(OA...