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Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
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Studying polymer diffusiophoresis with non-equilibrium molecular dynamics.
S Ramírez-Hinestrosa1, H Yoshida2, L Bocquet2
1Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom.
The Journal of Chemical Physics
|May 3, 2020
Summary
We studied how polymers move in fluids with concentration gradients. Polymer movement (diffusiophoresis) depends non-monotonically on interactions, unlike solid particles.
Area of Science:
- Physical Chemistry
- Polymer Physics
- Computational Fluid Dynamics
Background:
- Diffusiophoresis describes particle motion in solute gradients.
- Understanding polymer behavior in such systems is crucial for microfluidics and materials science.
Purpose of the Study:
- To numerically investigate the diffusiophoresis of short polymer chains.
- To analyze the influence of monomer-solute interactions on polymer velocity.
- To compare polymer diffusiophoresis with that of solid particles.
Main Methods:
- Non-equilibrium molecular dynamics (NEMD) simulations were employed.
- Polymer chains were simulated in a fluid with a solute concentration gradient.
- The monomer-solute interaction strength was systematically varied.
Main Results:
- A non-monotonic relationship was observed between diffusiophoretic mobility and monomer-solute interaction strength.
- Polymer chain length showed a weak dependence on diffusiophoretic mobility, differing from solid particle behavior.
- Hydrodynamic flow through the polymer was significantly less screened compared to pressure-driven flows.
Conclusions:
- The diffusiophoretic response of polymers is complex and depends strongly on solute interactions.
- Polymers exhibit distinct diffusiophoretic characteristics compared to solid particles, particularly regarding chain length effects.
- The reduced flow screening in polymers has implications for transport phenomena in complex fluids.
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