Structuring of polymer solutions upon solvent evaporation

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...

Porous Fiber Formation in Polymer-Solvent System Undergoing Solvent Evaporation

Polymer size in dilute solutions in the good-solvent regime.

We determine the density expansion of the radius of gyration, of the hydrodynamic radius, and of the end-to-end distance for a monodisperse polymer solution in good-solvent conditions. We consider the scaling limit (large degree of polymerization), including the leading scaling corrections. Using the expected large-concentration behavior, we extrapolate these low-density expansions outside the ...

Instabilities during the evaporation of a film: non glassy polymer + volatile solvent

We consider solutions where the surface tension of the solvent γs is smaller than the surface tension of the polymer γp. In an evaporating film, a plume of solvent rich fluid, then induces a local depression in surface tension, and the surface forces tend to strengthen the plume. We give an estimate (at the level of scaling laws) for the minimum thickness e ∗ required to obtain this instability...

Ultra fast processes for solvent evaporation in thin polymer films below Tg

The solvent diffusion coefficient D in a solvent-polymer system can be much larger than the ratio a/ , where a is one monomer length (about 0.5 nm) and is the dominant relaxation time measured e.g. by broadband dielectric spectroscopy [1,2]. The discrepancy can be by up to 6 orders of magnitude and more. We propose here that the solvent diffusion is dominated by path in the liquid with fast rel...