Correction for Jadhao and Robbins, Probing large viscosities in glass-formers with nonequilibrium simulations

PHYSICS Correction for “Probing large viscosities in glass-formers with nonequilibrium simulations,” by Vikram Jadhao and Mark O. Robbins, which was first published July 10, 2017; 10.1073/pnas.1705978114 (Proc Natl Acad Sci USA 114:7952–7957).

The authors note, “It has been brought to our attention that representing the experimentally measured Newtonian viscosity value by a set of points on a horizontal line in Fig 2B might mislead readers into thinking that measurements were made at the indicated strain rates. Low–strain-rate data points in Fig. 2B at pressures of 0.1, 100, 200, 300, 400, and 500 MPa are attributed to references 20, 24, and 25 when the points do not correspond to actual experimental data. The y-axis values for these points are the experimental low-shear viscosities for the corresponding pressures reported in ref. 20. We have revised Fig. 2B to remove these 24 data points (4 per curve) along the 0.1, 100, 200, 300, 400, and 500 MPa lines. The revised figure depicts the same experimental Newtonian viscosity value for each pressure by a horizontal line to indicate the limiting low–strain-rate behavior. We hope that this change eliminates any unintended confusion. This revision does not affect any of the conclusions drawn in the original article.” The corrected Fig. 2 and its corrected legend appear below.

Fig. 2.

Steady-state shear stress σ and viscosity $\eta$ of squalane as a function of strain rate $\dot{\gamma }$. Stress σ vs. $\dot{\gamma }$ at T = 293 K for P from 0.1–955 MPa (A) and viscosity $\sigma /\dot{\gamma }$ vs. $\dot{\gamma }$ (B) for the same systems. Symbols for $\dot{\gamma }\ge {10}^5{s}^{-1}$ correspond to MD simulation results. Data points at lower rates for P ≥ 636 MPa are from nonequilibrium experiments (24, 25). For P ≤ 500 MPa, only low-rate measurements have been reported (20). The limiting Newtonian viscosities (20) are indicated by horizontal dotted lines that are labeled above by the pressure. These dotted lines are extended to rates where they can be directly compared with simulation results or to the Newtonian limit of Eyring fits (black dashed lines) to simulation data for ${10}^6{s}^{-1}\le \dot{\gamma }\le {10}^9{s}^{-1}$. These fits for P ≥ 300 MPa (A) show a linear dependence of stress on $\log \dot{\gamma }$ for high $\dot{\gamma }$ and (B) extrapolate to the Newtonian viscosity at low rates. For P ≤ 500 MPa, simulations reach the Newtonian limit without extrapolation.