CBP Logo

COMPUTATIONAL BIOPHYSICS

UNIVERSITY OF TWENTE
THE NETHERLANDS
welcome
people
highlights
research
publications
education
alumni
twentanglement
Briels trophy
downloads
vacancies
contact us
introduction projects publications contact

Introduction

Twentanglements is a simulation package for mesoscopic polymer dynamics simulations. The package contains the Twentanglement uncrossability algorithm, which can be used in several types of mesoscale simulation methods. The program uses background friction (Langevin dynamics) or a pairwise friction.

An atomistic polyethylene chain and its coarse-grain representation Coarse graining from a molecular dynamics simulation to a mesoscale results in soft repulsive potentials between the blobs. This will cause unphysical bondcrossings influencing the dynamics of the system. The Twentanglement uncrossability constraint prevents these bond crossings. Simulations of a polyethylene melt show that the rheology is described correctly using this bottom-up method. The blob-blob interactions are deducted from MD simulations, as well as the friction parameters. No fitting parameters have been introduced!

The complete package includes the Krak mesoscale simulation program. Krak is built around the Twentanglement subroutine and is capable of simulating various polymeric systems, e.g. polymer melts, diluted polymers, amphiphilic systems, diblock copolymers, star like polymers, etcetera. It analyses thermodynamic data, trajectories, average end-to-end vectors, radii of gyration, order tensors, mean square displacements, autocorrelations (stress, velocity, Rouse modes). However, the Twentanglement algorithm can also be used as a plugin in your favourite simulation program. The manual describes the way to implement it.