Effect of Solvent Quality on the Coil−Stretch Transition
| Autor: | Shikha Somani, Eric S. G. Shaqfeh, J. Ravi Prakash |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
chemistry.chemical_classification
Quantitative Biology::Biomolecules Polymers and Plastics Organic Chemistry Thermodynamics Energy landscape Polymer Activation energy Strain rate Condensed Matter::Soft Condensed Matter Inorganic Chemistry Solvent chemistry Excluded volume Materials Chemistry Brownian dynamics Physical chemistry Scaling |
| Zdroj: | Macromolecules. 43:10679-10691 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/ma1019945 |
| Popis: | Polymers undergo a sharp coil−stretch transition in extension dominated flows when the strain rate exceeds a critical strain rate. We investigate this transition in both Θ solvents and good solvents using Brownian dynamics simulations. The polymer is represented by a bead−spring chain model undergoing elongational flow and solvent-mediated effects such as fluctuating hydrodynamic interactions (HI) and excluded volume (EV) are included rigorously. A 1-D energy landscape theory with an activation energy for transition(1) is used to gain qualitative insights into the dynamics. A key factor in determining the influence of solvent quality is the use of a proper measure of solvent quality.(2, 3) Contrary to earlier findings, it is observed that with improvement in solvent quality, the critical strain rate at which the coil to stretch transition takes place decreases. Furthermore, the solvent quality has a profound effect on the scaling of the critical strain rate with molecular weight and on both the transient ... |
| Databáze: | OpenAIRE |
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