Probing large viscosities in glass-formers with nonequilibrium simulations
Abstract
As a liquid cools, molecules move more slowly and the viscosity rises. A fundamental question is whether this trend continues smoothly down to zero temperature, or if flow stops at a finite temperature where the material undergoes a transition to a glass phase. Direct measurements of growing viscosities become difficult as the time for motion exceeds years or centuries. We describe and test an approach for obtaining large viscosities using nonequilibrium molecular dynamics simulations. Results agree with existing experiments on the model glass-former squalane and allow viscosities over 10 orders of magnitude larger to be predicted. The temperature dependence at fixed pressure or density is consistent with a gradual slowing of dynamics, rather than a finite-temperature divergence in viscosity.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jul 10, 2017
- Source ID
- 10.1073/pnas.1705978114
Entities
People
- Mark O. Robbins
- Vikram Jadhao
Organizations
- Indiana University
- Johns Hopkins University
- United States Army Research Laboratory