DIFFUSION COEFFICIENTS IN POLYMER-SOLVENT SYSTEMS FOR HIGHLY CONCENTRATED POLYMER SOLUTIONS

Diffusion Coefficients in Polymer- Solvent Systems for Highly Concentrated Polymer Solutions

The Vrentas/Duda proposal for the diffusion of polymer-solvent systems, which is based on the free-volume theory, was employed in correlating and predicting mutual diffusion coefficients in highly concentrated polymer solutions. It has been observed that the predictive version of the model is capable of qualitatively representing the experimental data, while the use of an adjustable parameter g...

Multi-Component Diffusion in Polymer-Solvent Systems

Structuring of polymer solutions upon solvent evaporation.

The morphology of solution-cast, phase-separated polymers becomes finer with increasing solvent evaporation rate. We address this observation theoretically for a model polymer where demixing is induced by steady solvent evaporation. In contrast to what is the case for a classical, thermal quench involving immiscible blends, the spinodal instability initially develops slowly and the associated l...

Virial coefficients and osmotic pressure in polymer solutions in good-solvent conditions.

We determine the second, third, and fourth virial coefficients appearing in the density expansion of the osmotic pressure Pi of a monodisperse polymer solution in good-solvent conditions. Using the expected large-concentration behavior, we extrapolate the low-density expansion outside the dilute regime, obtaining the osmotic pressure for any concentration in the semidilute region. Comparison wi...

Diffusion in Polymer Solids and Solutions

The industrial importance of penetrable and/or impenetrable polymer systems is evident when one faces with a huge number of publications considering various aspects of diffusion phenomenon. Strong worldwide interest to realize more details about the fundamental of the process, generalize the governed laws to new findings, and find fast and reliable techniques of measurement, makes motivation to...