Lammelar phase of diblock copolymer melt under shear kinetics and.pdf

Lammelar phase of diblock copolymer melt under shear: kineticsand conformational analysis.A.V. Zvelindovsky, G.J.A. Sevink, B.A.C. van Vlimmeren, N.M. Maurits, J.G.E.M. FraaijeDept. Biophysical Chemistry, University of Groningen,Nijenborgh 4, 9747 AG Groningen, The NetherlandsShort title: Lammelar phase of copolymer melt under shear.Key words: shear, polymer, lammelar, density functional.Address for proofs:Dr A V Zvelindovsky,Dept. Biophys. Chem.,University of Groningen,Nijenborgh 4, 9747 AG Groningen,The Netherlands 1 Abstract3D computer simulations of lammelar phase of a diblock copolymer meltunder simple steady shear are performed. The polymer system is describedby the density functional as a collection of Gaussian chains in a mean eldenvironment. The 3D mesophase morphology is obtained as a solution of adiusion-convection equation with random noise eld. Here, an analysis ofpolymer chain conformations in lamellae is considered. 2 Because of the wide area of industrial applications the behaviour of complex polymersystems in shear ows is intensively studied both experimentally and theoretically [1{3].The stability of morphology structures and phase transitions in complex polymer liquids inshear have been investigated by many authors [4{7]. During the last years the kinetics ofmorphologies of complex uids in applied external shear has also been studied by computersimulation techniques using time dependent Landau-Ginzburg models [8{13]. These modelsare based on traditional free energy expansion methods [14{16] which contain only the basicphysics of phase separation [17]. In contrast to these phenomenological theories we do nottruncate the free energy at a certain level, but rather retain the full polymer path integralby a numerical procedure [17{23]. Recently Kawakatsu and Doi started to use a similarapproach [24,25].Calculation of polymer path integrals is computationally very intensive and requiresecient numerical techniques. However it allows us to describe