Predicting optimal chain lengths in atomistic simulations of solvated polymers

ABSTRACT

Currently, clear guidance is not available for determining the minimum practical chain lengths needed for achieving reasonable convergence when performing atomistic simulations of common synthetic polymers. Here, we analyze a collection of polymers, including polypropylene (PP), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene glycol (PEG), poly(methyl methacrylate) (PMMA), polystyrene (PS), and polyvinyl chloride (PVC), with chain lengths varying from 5 to 240 repeat units. We exclusively focus on solvated polymer systems, and we report the convergence of several characteristic properties, such as radial distribution functions (RDFs), surface area per repeat unit (SASA/N), ratio of mean squared end-to-end distance to mean squared radius of gyration (${\displaystyle \frac{⟨R^2⟩}{⟨R_g^2⟩}}$), and surface electrostatic potential distributions. Based on these data, we propose a general relationship for identifying minimum practical chain lengths for performing atomistic simulations of solvated linear synthetic polymers, which is based on the SASA/N.

KEYWORDS:

• Chain length
• atomistic simulations
• upcycling
• molecular dynamics

Acknowledgements

We are grateful to the Alabama Supercomputer Authority for computational support.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Availability of data and materials

The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Additional information

Funding

This work is supported by the National Science Foundation (Award Nos. 2132133 and 2029387).