Paper Number
VP26 

Session
Pre-recorded Flash Presentations (virtual)

Title
Rheology of semiflexible polymers in shear flow via Brownian dynamics and quasi-two-parameter theory

Presentation Date and Time
All Week (Asynchronous) Any Time

Track / Room
Pre-recorded Presentation / Virtual

Authors (Click on name to view author profile)

  1. Pincus, Isaac M. (Monash University, Chemical Engineering)
  2. Alison, Rodger (Macquarie University, Molecular Sciences)
  3. Prakash, J. Ravi (Monash University, Chemical Engineering)

Author and Affiliation Lines (in printed abstract book)
Isaac M. Pincus1, Rodger Alison2 and J. Ravi Prakash1
1Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia; 2Molecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia

Speaker / Presenter 
Pincus, Isaac M.

Keywords
theoretical methods; computational methods; non-Newtonian fluids; polymer solutions

Text of Abstract

Even in dilute solutions, quantitatively predicting the shear rheology of semiflexible polymers using parameter-free methods is to date not possible for arbitrary chemical structures and sufficiently large molecular weights. For example, even for a model polymer such as DNA in excess salt, it is not possible to accurately predict the shear-thinning exponent for a particular molecular weight [1].Part of this difficulty arises due to the nature of the coarse-grained bead-spring or bead-rod approximations used to model the polymer molecule, which often give different predictions depending on the details of spring force laws, how hydrodynamic interactions or excluded volume effects are introduced, and whether bending or torsional potentials are used [2,3]. Here we propose a coarse-graining scheme which is consistent with the quasi-two-parameter theory for treating excluded volume effects in dilute solutions of semiflexible polymers [4]. We use a spring force law which can mimic both a traditional FENE spring as well as a rigid rod [5,6], along with a bending potential to account for semiflexiblity. This scheme allows for consistent modelling of a variety of polymer types and molecular weights, shedding light on how this variety affects rheology in shear flow.

[1] S. Pan, D. A. Nguyen, B. Dunweg, P. Sunthar, T. Sridhar, J. Ravi Prakash, J. Rheol. 62 (2018) 845–867

[2] I. S. Dalal, C. Hsieh, A. Albaugh, R. G. Larson, AIChE Journal 60 (2014) 1400–1412.

[3] A. Saadat, B. Khomami, J. Chem. Phys 145 (2016) 204902.

[4] H. Yamakawa, Helical wormlike chains in polymer solutions, 2nd ed., Heidelberg Springer,2016.

[5] I. Pincus, A. Rodger, J. R. Prakash, J. Non-Newtonian Fluid Mech. 285 (2020) 104395.

[6] C. Hsieh, S. Jain, R. G. Larson, J. Chem. Phys 124 (2006) 044911