Glassy behavior of a homopolymer from molecular dynamics simulations.
We study at- and out-of-equilibrium dynamics of a single homopolymer chain at low temperature using molecular dynamics. The main quantities of interest are the average root mean square displacement of the monomers below the theta point, and the structure factor, as a function of time. The observation of these quantities show a close resemblance to those measured in structural glasses and suggest that the polymer chain in its low temperature phase is in a glassy phase, with its dynamics dominated by traps. In equilibrium, at low temperature, we observe the trapping of the monomers and a slowing down of the overall motion of the polymer as well as nonexponential relaxation of the structure factor. Out of equilibrium, at low temperatures, we compute the two-time quantities and observe breaking of ergodicity in a range of waiting times, with the onset of aging.
Dokholyan
Nikolay V
NV
Center for Polymer Studies, Physics Department, Boston University, Boston, Massachusetts 02215, USA.
Pitard
Estelle
E
Buldyrev
Sergey V
SV
Stanley
H Eugene
HE
D001703:Biophysics / Q000379:methods*; D007700:Kinetics; D015233:Models, Statistical; D011108:Polymers / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors
D011108:Polymers