The dynamic mean-field density functional method is adapted to describe phase separation in the presence of geometrical constraints. We observe that inclusion of small filler particles (such as rods) already has a dramatic effect on the morphology of polymer melts. The effect is comparable to the effect of applied simple steady shear. Mesostructures in the presence of large filler particles such as plates are totally governed by the geometry of the particle. Effects of polymer–surface interactions on morphology formation are investigated in detail.
In this paper we extend the dynamic mean-field density functional method, derived from the generalized time-dependent Ginzburg-Landau theory, to the mesoscopic dynamics of compressible polymer liquids. We discuss and compare different classes of compressibility models: exactly incompressible, the Helfand's harmonic penalty model, and a cell model. We present numerical results and show that the penalty model is a very practical and easy to use solution. In the current nVT ensemble dynamics algorithms application of the cell model leads to a variation of the pressure and, depending on conditions, the system develops liquid-gas transitions. We show that the morphology of a phase separated diblock copolymer melt around a gas bubble has intruiging structures, with lamellar phases oriented towards the gas-liquid interface.
The first three-dimensional (3D) simulation of meso-phase formation in a specific polymer system—55% aqueous solution of the triblock polymer surfactant (EO)13(PO)30(EO)13—under simple steady shear is performed. The method is based on dynamic mean-field density functional theory. The hexagonal phase is investigated. The simulations reproduce recent experimental observations on the same polymer system.
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