String model for the dynamics of glass-forming liquids.
نویسندگان
چکیده
We test the applicability of a living polymerization theory to describe cooperative string-like particle rearrangement clusters (strings) observed in simulations of a coarse-grained polymer melt. The theory quantitatively describes the interrelation between the average string length L, configurational entropy Sconf, and the order parameter for string assembly Φ without free parameters. Combining this theory with the Adam-Gibbs model allows us to predict the relaxation time τ in a lower temperature T range than accessible by current simulations. In particular, the combined theories suggest a return to Arrhenius behavior near Tg and a low T residual entropy, thus avoiding a Kauzmann "entropy crisis."
منابع مشابه
An Overview on Short and Long Time Relaxations in Glass-forming Supercooled Liquids
Density fluctuations in supercooled liquids near the glass transition relax in multiple steps. The short time relaxation is known as β-relaxation and the final long time relaxation is called α-relaxation. It is believed that the long time α-relaxation is a cooperative phenomena associated with a growing length scales, whereas the short-time β-relaxation is often attributed to spatially local pr...
متن کاملStructural origin of fractional Stokes-Einstein relation in glass-forming liquids
In many glass-forming liquids, fractional Stokes-Einstein relation (SER) is observed above the glass transition temperature. However, the origin of such phenomenon remains elusive. Using molecular dynamics simulations, we investigate the break- down of SER and the onset of fractional SER in a model of metallic glass-forming liquid. We find that SER breaks down when the size of the largest clust...
متن کاملLinking rigidity transitions with enthalpic changes at the glass transition and fragility: insight from a simple oscillator model.
A low temperature Monte Carlo dynamics of a Keating-like oscillator model is used to study the relationship between the nature of network glasses from the viewpoint of rigidity, the thermal reversibility during the glass transition and the strong-fragile behaviour of glass-forming liquids. The model shows that a Phillips optimal glass formation with minimal enthalpic changes is obtained under a...
متن کاملDynamics of Glass Forming Liquids with Randomly Pinned Particles
It is frequently assumed that in the limit of vanishing cooling rate, the glass transition phenomenon becomes a thermodynamic transition at a temperature TK. However, with any finite cooling rate, the system falls out of equilibrium at temperatures near Tg(>TK), implying that the very existence of the putative thermodynamic phase transition at TK can be questioned. Recent studies of systems wit...
متن کامل7 cf ) Impulsive Stimulated Thermal Scattering of Glass - Forming Liquids
Impulsive Stimulated Thermal Scattering is a time domain laser spectroscopy that is applied to studying the relaxation dynamics of liquids in the supercooled temperature regime. Characterizing the relaxation dynamics of supercooled liquids is essential to developing an understanding of the physics of the liquid-glass transition. Mode Coupling Theory is a popular theory that has had some success...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of chemical physics
دوره 140 20 شماره
صفحات -
تاریخ انتشار 2014