Giant Casimir non-equilibrium forces drive coil to globule transition in polymers
| Autor: | Samanta, Himadri S., Mugnai, Mauro L., Kirkpatrick, T. R., Thirumalai, D. |
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| Rok vydání: | 2017 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | We develop a theory to probe the effect of non-equilibrium fluctuation-induced forces on the size of a polymer confined between two horizontal thermally conductive plates subject to a constant temperature gradient, $\nabla T$. We assume that (a) the solvent is good and (b) the distance between the plates is large so that in the absence of a thermal gradient the polymer is a coil whose size scales with the number of monomers as $N^{\nu}$, with $\nu \approx 0.6$. We predict that above a critical temperature gradient, $\nabla T_c \sim N^{-\frac{5}{4}}$, favorable attractive monomer-monomer interaction due to Giant Casimir Force (GCF) overcomes the chain conformational entropy, resulting in a coil-globule transition. The long-ranged GCF-induced interactions between monomers, arising from thermal fluctuations in non-equilibrium steady state, depend on the thermodynamic properties of the fluid. Our predictions can be verified using light-scattering experiments with polymers, such as polystyrene or polyisoprene in organic solvents (neopentane) in which GCF is attractive. Comment: 5 pages, 3 figures |
| Databáze: | arXiv |
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