تقرير
Aging Dynamics of a Fractal Model Gel
| العنوان: | Aging Dynamics of a Fractal Model Gel |
|---|---|
| المؤلفون: | Suarez, M-A., Kern, N., Pitard, E., Kob, W. |
| سنة النشر: | 2008 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Soft Condensed Matter, Condensed Matter - Disordered Systems and Neural Networks |
| الوصف: | Using molecular dynamics computer simulations we investigate the aging dynamics of a gel. We start from a fractal structure generated by the DLCA-DEF algorithm, onto which we then impose an interaction potential consisting of a short-range attraction as well as a long-range repulsion. After relaxing the system at T=0, we let it evolve at a fixed finite temperature. Depending on the temperature T we find different scenarios for the aging behavior. For T>0.2 the fractal structure is unstable and breaks up into small clusters which relax to equilibrium. For T<0.2 the structure is stable and the dynamics slows down with increasing waiting time. At intermediate and low T the mean squared displacement scales as t^{2/3} and we discuss several mechanisms for this anomalous time dependence. For intermediate T, the self-intermediate scattering function is given by a compressed exponential at small wave-vectors and by a stretched exponential at large wave-vectors. In contrast, for low T it is a stretched exponential for all wave-vectors. This behavior can be traced back to a subtle interplay between elastic rearrangements, fluctuations of chain-like filaments, and heterogeneity. Comment: 30 pages, 25 figures |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/0812.3559 |
| رقم الأكسشن: | edsarx.0812.3559 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |