Effect of solvent quality on the conformation and relaxation of polymers via dissipative particle dynamics

Abstract

Dissipative particle dynamics (DPD), a new simulation technique appropriate at mesoscopic length scales, has been applied to a dilute solution of polymer in solvents of varying quality. Unlike earlier simulations, the solvent is represented in the form mobile particulate packets, so that potential interferences of solvent flow about neighboring beads of the polymer are explicitly included. We establish that the mechanism used to vary the solvent quality produces a collapse transition, as judged both by static conformational and by dynamical criteria. The scaling of the polymer radius of gyration and of its longest dynamical relaxation time are in good agreement with accepted theory. The condition for transition from good to poor solvent is consistently predicted by several static and dynamical measures. Though the model that underlies DPD is not atomically detailed, the results presented strongly suggest that both excluded volume and hydrodynamic interaction must present.

Dissipative Particle Dynamics and other particle methods for multiphase fluid flow in fractured and porous media

“…One of the advantages of DPD is that it is capable of simulating the flow of particle suspensions, polymer solutions, emulsions, gels and other complex fluids and soft condensed matter. An important application, which is outside of the usual scope of computational fluid dynamics is the effects of fluid flow on polymer conformation (Kong et al, 1997). Dissipative particle dynamics could also be used to simulate the fragmentation of polymers, other large molecules and colloidal aggregates due to thermal and hydrodynamic forces.…”

Everything you always wanted to know about SDPD⋆ (⋆but were afraid to ask)

“…In fact, new forces (elastic, rigid, etc.) can be added between particles in order to describe long polymers [71][72][73][74] , rigid or deformable particles in suspension [75] , porous media [76] , droplets [77] , cells [78][79][80] , or even more complex thixotropic materials [81] (see Fig. 1).…”

Mesoscopic Multi-particle Collision Model for Fluid Flow and Molecular Dynamics

“…Indeed, time scale separation between the microscopic collision processes and hydrodynamic flows that define the long time evolution of a polymer chain makes direct simulations of polymer dynamics a challenging task. Therefore, in simulations, it is suitable to replace molecular solvents with mesoscale models [36][37][38]. Multi-particle collision dynamics can be adapted to model polymer flows [38].…”