The Computer Simulation of Dilute Solution Particle Dynamics

A computer program designed to predict the behavior of arbitrary bead/rod/spring models in dilute solution is described. Equilibrium, shear and extensional flow fields are considered. The program tracks particles individually and is therefore capable of calculating statistical averages of a wide range of properties; particle inertia and Brownian motion are included in the simulation, although hydrodynamic interaction is not. A variant of the SHAKE algorithm from molecular dynamics is used to handle constraints. A systematic investigation is conducted to assess the sensitivity of conformational statistics to particle geometry, connector rigidity, inertia, and Brownian motion under equilibrium and flow conditions. The program is used to verify the equilibrium internal angle distribution functions for elastic and rigid trimers with and without inertia. In addition, the program is used to predict the values of conformational statistics for linear chains under equilibrium and flow conditions. In particular, equilibrium distribution functions and flow transition diagrams are constructed for the end-to-end distance, the radius of gyration, and the 3D orientation function. For the linear polymer with Brownian motion, the shear transition shows evidence of what has been termed rolling behaviour. At high shear rates, the ends of the polymer are displaced into the flow by Brownian motion, where they are dragged back towards the center so the particle rolls up into a ball, only to undergo further cycles of extension and rolling. The ability of the program to handle arbitrary connectivity matrices is used to simulate branched chains. New results, including equilibrium distribution functions and flow transition diagrams are presented for Brownian rings, stars, trees and combs at equilibrium and in flow. Similar rolling behaviour is observed for branched structures in shear. Orientation is found to precede chain (particle) extension in both shear and extension. This effect is found to be more pronounced in extensional flow.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

1990

Author dc:creator

• Roy, Tuhin Kumar

Advisor dc:contributor.advisor

• Mackley, M. R.

• Computer simulation
• Dilute solution particle dynamics

Licence

• https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/8e024f02-571f-49a1-acac-a2a85a3fa71b/download
• https://www.rioxx.net/licenses/all-rights-reserved/

Language dc:language

en

DOI dc:identifier.doi

https://doi.org/10.17863/CAM.87932

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/340496