Dynamic Density Functional Theory for Sheared Polymeric Systems

Abstract

Summary: Details of the dynamic density functional theory for sheared polymer systems are presented. The method is illustrated on polymer blends with and without compatibilizers. Shearing slows down coarsening of structures at later stages of phase separation, trapping the system in kineticly driven metastable states. Under certain conditions the system is found trapped in a metastable multiple sphere morphology, while under other conditions a sphere‐to‐string transition is observed. The results are sensitive to the (block co)polymer architecture.

Electrically conductive sensors for liquids based on quaternary ethylene vinyl acetate (EVA)/copolyamide/maleated‐EVA/polyaniline blends

“…Flow conditions present a more complicated picture. In general, shearing slows down coarsening in polymer blends, leading to metastable drop size that is dependent on shear rate 14. However, there are at least two opposing forces that determine the compatibilized polymer morphology 15.…”

“…1). The good dispersion of the CoPA phase observed at high shear rates is a kinetically frozen morphology that is due to breaking up of large CoPA regions into smaller ones, on the one hand, and prevention of coalescence on the other hand 14, 17…”

Kinetic pathways of sheared block copolymer systems derived from Minkowski functionals

“…The microstructure patterns are described by the coarse grained variables, which are the density fields I (r) of the different species I. Given these density fields a free energy functional F͓͔ can be defined as follows: [20][21][22] F͓͔ϭϪkT ln ⌿ n n!…”

“…Here ␥ is the shear rate ͑the time derivative of the shear strain ␥͒ and sheared boundary conditions apply. 20,[25][26][27][28]…”

Superdomain dynamics in ferroelectric-ferroelastic films: Switching, jamming, and relaxation

“…Both Chen and Zvelindovsky et al found [12][13][14][15][16][17][18] power-law dependences with exponents very near ¼, as does Sinha [14]. There is a good earlier study of this problem by Kohn and Otto [19] based upon surface diffusion.…”