Viscoelastic phase separation model for ternary polymer solutions

Critical polymer-polymer phase separation in ternary solutions.

We study polymer-polymer phase separation in a common good solvent by means of Monte Carlo simulations of the bond-fluctuation model. Below a critical, chain-length-dependent concentration, no phase separation occurs. For higher concentrations, the critical demixing temperature scales nonlinearly with the total monomer concentration, with a power law relatively close to a renormalization-group ...

ternary phase diagram for polymer/ solvent/ supercritical-CO2by sanchez-lacombe model

Phase-separation Phenomena in Polymer Solutions

Viscoelastic properties of polymer solutions.

In a concentrated polymer solution, the entanglement of long-chain molecules results in a transient network structure, to which may be attributed certain aspects of the viscoelastic behavior of such a system. A suitable mechanical model for representing this network as a first approximation is a retarded Maxwell element with one spring and two dashpots. Experimental measurements of mechanical p...

Phase Separation in Polymer Solutions Induced by Shear

We numerically investigate nonlinear regimes of shear-induced phase separation in entangled polymer solutions. Use is made of a time-dependent Ginzburg-Landau model describing two fluid dynamics of polymer and solvent. As a new dynamic variable a conformation tensor is introduced to represent chain deformations. Above the coexistence curve a dynamical steady states is attained, where fluctuatio...