Diffuse interface modeling of the morphology and rheology of immiscible polymer blends

Abstract

A diffuse interface model is used to simulate a step-shear experiment of a binary immiscible polymer blend. The gradient theory used in diffuse interface modeling makes it possible to incorporate interfacial tension and governs the process of coalescence and breakup without any additional decision criteria. The interface tensor q, a direct outcome of the model, is used to relate microstructural information to the first-normal stress difference N 1 . The results obtained are in qualitative agreement with experiments reported in the literature.

Diffuse Interface Modeling of Droplet Impact on a Pre‐Patterned Solid Surface

“…The size of the entrapped ambient fluid is, in all the three cases, smaller than the stable size dictated by the thermodynamics. [15,16] Consequently, the entrapped fluid dissolves in the droplet due to the c 4 description of the free energy used in thermodynamic formulation. [16] Meanwhile, the droplet continues to spread, until it reaches the maximum extent which is seen to be larger for smaller values of y barrier .…”

“…[15,16] Consequently, the entrapped fluid dissolves in the droplet due to the c 4 description of the free energy used in thermodynamic formulation. [16] Meanwhile, the droplet continues to spread, until it reaches the maximum extent which is seen to be larger for smaller values of y barrier . In particular for y barrier ¼ 608 the droplet spreads until the top-outer edge of the barrier is reached.…”

Spontaneous shrinkage of drops and mass conservation in phase-field simulations

“…In recent years, the phase-field model has gained popularity in simulating two-phase flows of immiscible fluids [1][2][3][4][5][6], and the method is the subject of several review articles [7][8][9]. In this framework, the fluid interface is treated as a thin but diffuse layer where the two components mix to some extent.…”

Incorporating Fluctuations and Dynamics in Self-Consistent Field Theories for Polymer Blends

“…Also the assumption of local equilibrium for the chain conformations, which allows us to use the SCF free energy functional, has to be questioned critically. Methods have been devised to incorporate some of these complications [73,94,108,107], but the development in this area is still in its early stages.…”

“…We have merely illustrated the simplest possible case -the early stages of spontaneous phase separation within a purely diffusive dynamics. In applications hydrodynamic effects [106,107], shear and viscoelasticity [108] might become important. Even deceptively simple situations -like nucleation phenomena in binary polymer blends -still pose challenging questions [109].…”