Paper Number
PO42 

Session
Poster Session

Title
Simulating nanoparticle dynamics in semidilute polymer solutions with multiparticle collision dynamics

Presentation Date and Time
October 17, 2018 (Wednesday) 6:30

Track / Room
Poster Session / Woodway II/III

Authors (Click on name to view author profile)

  1. Chen, Renjie (University of Houston, Chemical and Biomolecular Engineering)
  2. Poling-Skutvik, Ryan (University of Houston, Chemical and Biomolecular Engineering)
  3. Nikoubashman, Arash (Johannes Gutenberg University Mainz, Institute of Physics)
  4. Howard, Michael P. (The University of Texas at Austin, McKetta Department of Chemical Engineering)
  5. Egorov, Sergei A. (University of Virginia, Department of Chemistry)
  6. Conrad, Jacinta C. (University of Houston, Chemical and Biomolecular Engineering)
  7. Palmer, Jeremy C. (University of Houston, Chemical and Biomolecular Engineering)

Author and Affiliation Lines (in printed abstract book)
Renjie Chen1, Ryan Poling-Skutvik1, Arash Nikoubashman2, Michael P. Howard3, Sergei A. Egorov4, Jacinta C. Conrad1, and Jeremy C. Palmer1
1Chemical and Biomolecular Engineering, University of Houston, Houston, TX; 2Institute of Physics, Johannes Gutenberg University Mainz, Staudingerweg, Germany; 3McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX; 4Department of Chemistry, University of Virginia, Charlottesville, VA

Speaker / Presenter 
Chen, Renjie

Text of Abstract
The dynamics of nanoparticles in complex fluids are of great interest for applications in drug delivery, oil recovery and materials processing. Particle mobility is well described by the generalized Stokes-Einstein (GSE) relation when the nanoparticles are much larger than the polymers . Violations of GSE predictions are observed, however, when the size of nanoparticles is comparable to or smaller than length scales in polymer solutions.1 We investigate the microscopic origin of this anomalous behavior using advanced particle-based simulation techniques,2 with the multi-particle collision dynamics3 (MPCD) scheme providing a computationally efficient route to modeling solvent-mediated hydrodynamic interactions in nanoparticle-polymer systems. We demonstrate that the translational center-of-mass motions of both nanoparticles and polymers are sub-diffusive on short times before transitioning into a diffusive regime on longer time scales.2 The long-time diffusivities of nanoparticles collapse according to scaling predictions.4 The sub-diffusive exponents of nanoparticles and polymer centers-of-mass are highly correlated, suggesting that polymer center-of-mass translational motions as well as local polymer relaxations play a role in the coupling between the dynamics of polymers and nanoparticles. Finally, we perform simulations in which we tune the flexibility of the polymers. As the persistence length of the polymers increases, the nanoparticle dynamics become more subdiffusive and decouple from the dynamics of the polymer chain center-of-mass.
References:
[1] R. Poling-Skutvik, R. Krishnamoorti, and J. C. Conrad, ACS Macro Lett., 2015, 4, 1169-1173
[2] R. Chen, R. Poling-Skutvik, A. Nikoubashman, M. P. Howard, J. C. Conrad, and Jeremy C. Palmer, Macromolecules, 2018, 51, 1865-1872
[3] A. Malevanets and R. Kapral, J. Chem. Phys., 1999, 17, 8605-8613
[4] L.-H. Cai, S. Panyukov, and M. Rubinstein, Macromolecules, 2011, 44, 7853–7863