Evaluation of the Slip-Spring Dissipative Particle Dynamics Code for Practical Studies in Polymer Rheology

We evaluated three slip-spring dissipative particle dynamics models implemented in the general-purpose coarse-grained molecular dynamics program COGNAC. One fixed number of the slip-spring model proposed by Langoloth and co-workers and the two grand canonical models proposed by Unemaya and Masubuchi, and by Ramírez-Hernández and co-workers were implemented based on their original papers. Each implementation was validated by reproducing the original results. The details behind all the settings of the various parameters such as fictitious chemical potentials used in the grand canonical methods were studied. A linear relationship between the slip-spring density and exp(ν/kBT) was confirmed for the Uneyama and Masubuchi algorithm, where ν is a fictitious chemical potential. Moreover, the coefficient for our implementation was determined to enable quantitative adjustments to the slip-spring density for each target application. With the slip-spring model being a promising model in the study of rheological properties of entangled polymer melts and solutions, this work contributes by advancing the application of the slip-spring model both in academia and industry.