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Full-Text Articles in Chemical Engineering
Coarsening Dynamics Of Ternary Polymer Solutions With Mobility And Viscosity Contrasts, Jan Ulric Garcia, Douglas R. Tree, Alyssa Bagoyo, Tatsuhiro Iwama, Kris T. Delaney, Glenn H. Fredrickson
Coarsening Dynamics Of Ternary Polymer Solutions With Mobility And Viscosity Contrasts, Jan Ulric Garcia, Douglas R. Tree, Alyssa Bagoyo, Tatsuhiro Iwama, Kris T. Delaney, Glenn H. Fredrickson
Faculty Publications
Using phase-field simulations, we investigate the bulk coarsening dynamics of ternary polymer solutions undergoing a glass transition for two models of phase separation: diffusion only and with hydrodynamics. The glass transition is incorporated in both models by imposing mobility and viscosity contrasts between the polymer-rich and polymer-poor phases of the evolving microstructure. For microstructures composed of polymer-poor clusters in a polymer-rich matrix, the mobility and viscosity contrasts significantly hinder coarsening, effectively leading to structural arrest. For microstructures composed of polymer-rich clusters in a polymer-poor matrix, the mobility and viscosity contrasts do not impede domain growth; rather, they change the transient …
Modeling The Relaxation Time Of Dna Confined In A Nanochannel, Douglas R. Tree, Yanwei Wang, Kevin D. Dorfman
Modeling The Relaxation Time Of Dna Confined In A Nanochannel, Douglas R. Tree, Yanwei Wang, Kevin D. Dorfman
Faculty Publications
Using a mapping between a Rouse dumbbell model and fine-grained Monte Carlo simulations, we have computed the relaxation time of λ-DNA in a high ionic strength buffer confined in a nanochannel. The relaxation time thus obtained agrees quantitatively with experimental data [Reisner et al., Phys. Rev. Lett. 94, 196101 (2005)] using only a single O(1) fitting parameter to account for the uncertainty in model parameters. In addition to validating our mapping, this agreement supports our previous estimates of the friction coefficient of DNA confined in a nanochannel [Tree et al., Phys. Rev. Lett. 108, 228105 …
Is Dna A Good Model Polymer?, Douglas R. Tree, Abhiram Muralidhar, Patrick S. Doyle, Kevin D. Dorfman
Is Dna A Good Model Polymer?, Douglas R. Tree, Abhiram Muralidhar, Patrick S. Doyle, Kevin D. Dorfman
Faculty Publications
The details surrounding the crossover from wormlike-specific to universal polymeric behavior has been the subject of debate and confusion even for the simple case of a dilute, unconfined wormlike chain. We have directly computed the polymer size, form factor, free energy, and Kirkwood diffusivity for unconfined wormlike chains as a function of molecular weight, focusing on persistence lengths and effective widths that represent single-stranded and double-stranded DNA in a high ionic strength buffer. To do so, we use a chain-growth Monte Carlo algorithm, the pruned-enriched Rosenbluth method (PERM), which allows us to estimate equilibrium and near-equilibrium dynamic properties of wormlike …