Work

Structure and Flow-Viscosity of Filled-Polymer-Based 3D Printing Ink: Exploration through Coarse-Grained Molecular Dynamics

Year: 2026

Type: article

Abstract: The addition of nanofiller particles to a polymer matrix has long been known to enhance or modify the composite's mechanical and rheological properties. However, quantitatively capturing such changes with molecular level simulations remains computationally challenging. Toward that goal, we performed coarse-grained molecular dynamics of a nanocomposite system at a fixed (25 vol %) filler loading under nonspecific, weak polymer-filler interactions representative of a broad class of technologically important materials. We report several interesting results, including: (1) the equilibrium chain-configuration remains Gaussian-like as in an unfilled melt; (2) smaller filler particles display a stronger tendency to cluster; (3) larger fillers act as plasticizers by reducing the entanglement density and accelerating the chain mobility; and (4) fillers enhance the tensile response modulus, with the effect being stronger for larger particles. We also simulate cluster breakup, yielding, and elongational flow under an applied time-linear tensile strain and study the flow viscosity as a function of filler-size and chain-length.

Source: ACS Omega

DOI: 10.1021/acsomega.5c11248

Authors: Supun S. Mohottalalage, John J. Karnes, Spencer C. Schmidt, Todd H. Weisgraber, Andrew P. Saab, Amitesh Maiti

Institution: Lawrence Livermore National Laboratory

Language: English

Topic: Rheology and Fluid Dynamics Studies

Subfield: Fluid Flow and Transfer Processes

Field: Chemical Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,935

Funders: U.S. Department of Energy, Lawrence Livermore National Laboratory