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Dynamical self-consistent field theory for kinetics of structure formation in dense polymeric systems. Douglas J. Grzetic CAP Congress 2014 Advisor: Robert A. Wickham. Introduction. Interacting many-body problem. particle-based simulation (MD, Brownian dynamics).
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Dynamical self-consistent field theory for kinetics of structure formation in dense polymeric systems Douglas J. Grzetic CAP Congress 2014 Advisor: Robert A. Wickham
Introduction • Interacting many-body problem particle-based simulation (MD, Brownian dynamics) coarse-grained field theories (DFT, tdGL, etc)
Introduction • Interacting many-body problem particle-based simulation (MD, Brownian dynamics) coarse-grained field theories (DFT, tdGL, etc) ?
First-principles microscopic dynamics • Many-body interacting Langevin equation spring force “Fspr” random force drag force non-bonded interaction force
Dynamical self-consistent field theory • Dynamical mean-field approximation • Derived from first-principles microscopic dynamics D. J. Grzetic, R. A. Wickham and A.-C. Shi, Statistical dynamics of classical systems: A self-consistent field approach, J. Chem. Phys. (2014, in press)
Potential applications to dynamical problems entangled chain dynamics colloidal dynamics http://www.nonmet.mat.ethz.ch/research/ Colloidal_Chemistry_Ceramic_Processing/Colloid_Chemistry.jpg active matter phase separation kinetics http://upload.wikimedia.org/wikipedia/commons/3/32/ EscherichiaColi_NIAID.jpg R. K. W. Spencer and R. A. Wickham, Soft Matter (2013)
Potential applications to dynamical problems entangled chain dynamics colloidal dynamics http://www.nonmet.mat.ethz.ch/research/ Colloidal_Chemistry_Ceramic_Processing/Colloid_Chemistry.jpg active matter phase separation kinetics http://upload.wikimedia.org/wikipedia/commons/3/32/ EscherichiaColi_NIAID.jpg R. K. W. Spencer and R. A. Wickham, Soft Matter (2013)
Dynamical self-consistent field theory density: mean field: functional Smoluchowski equation: D. J. Grzetic, R. A. Wickham and A.-C. Shi, Statistical dynamics of classical systems: A self-consistent field approach, J. Chem. Phys. (2014, in press)
Dynamical self-consistent field theory density: mean field: functional Smoluchowski equation: D. J. Grzetic, R. A. Wickham and A.-C. Shi, Statistical dynamics of classical systems: A self-consistent field approach, J. Chem. Phys. (2014, in press)
Single-chain dynamics in a mean field • Equivalent Langevin simulation of chain dynamics (1.6 million chain ensemble) • Parallelizable (~1 day run time, 32 cores)
Microscopic (non-bonded) bead-bead interaction • Truncated Lennard-Jones interaction
Symmetric polymer blend: spinodal decomposition A B spinodal
Microphase separation in AB diblock copolymers A asymmetric B timescale ~102tR
Order-order transition: structure factor rA - rB structure factor
Chain configuration statistics: Rg map more stretched less stretched rA - rB radius of gyration, A block
Conclusions • Demonstrated ability to study kinetics of macro/microphase separation in large, dense inhomogeneous polymer systems • Truly non-equilibrium mean field theory • Connection to microscopic dynamics (Rg, tR) • Retain chain conformation statistics D. J. Grzetic, R. A. Wickham and A.-C. Shi, Statistical dynamics of classical systems: A self-consistent field approach, J. Chem. Phys. (2014, in press)