Combined description of polymer PVT and relaxation data using a dynamic “SL-TS2” mean-field lattice model

Soft Matter ◽  
2021 ◽  
Author(s):  
Valeriy V. Ginzburg

We develop a combined model to describe the pressure–volume–temperature (PVT) thermodynamics and the α- and β-relaxation time dynamics in glass-forming amorphous materials.

2006 ◽  
Vol 20 (19) ◽  
pp. 2795-2804 ◽  
Author(s):  
LETICIA F. CUGLIANDOLO

This article reviews recent studies of mean-field and one dimensional quantum disordered spin systems coupled to different types of dissipative environments. The main issues discussed are: (i) The real-time dynamics in the glassy phase and how they compare to the behaviour of the same models in their classical limit. (ii) The phase transition separating the ordered – glassy – phase from the disordered phase that, for some long-range interactions, is of second order at high temperatures and of first order close to the quantum critical point (similarly to what has been observed in random dipolar magnets). (iii) The static properties of the Griffiths phase in random king chains. (iv) The dependence of all these properties on the environment. The analytic and numeric techniques used to derive these results are briefly mentioned.


2015 ◽  
Vol 112 (8) ◽  
pp. 2361-2366 ◽  
Author(s):  
Manuel Sebastian Mariani ◽  
Giorgio Parisi ◽  
Corrado Rainone

The study of the properties of glass-forming liquids is difficult for many reasons. Analytic solutions of mean-field models are usually available only for systems embedded in a space with an unphysically high number of spatial dimensions; on the experimental and numerical side, the study of the properties of metastable glassy states requires thermalizing the system in the supercooled liquid phase, where the thermalization time may be extremely large. We consider here a hard-sphere mean-field model that is solvable in any number of spatial dimensions; moreover, we easily obtain thermalized configurations even in the glass phase. We study the 3D version of this model and we perform Monte Carlo simulations that mimic heating and cooling experiments performed on ultrastable glasses. The numerical findings are in good agreement with the analytical results and qualitatively capture the features of ultrastable glasses observed in experiments.


1976 ◽  
Vol 54 (7) ◽  
pp. 794-799 ◽  
Author(s):  
M. P. Madan

The dielectric relaxation behavior of 2-butanone, 2-pentanone, 2-heptanone, and 3-nonanone in dilute nonpolar solvents, n-heptane, cyclohexane, benzene, and carbon tetrachloride has been studied in the microwave region at a number of temperatures. The relaxation data have been used to estimate the free energy, enthalpy, and entropy of activation for the relaxation mechanism. The values of the relaxation time for those solutions for which there are available known data agree well with other determinations. The results have been discussed in terms of dipole reorientation by intramolecular and overall molecular rotation and compared, wherever possible, with other similar studies on aliphatic molecules.


2019 ◽  
Vol 28 (8) ◽  
pp. 086601
Author(s):  
Xing-Yu Zhao ◽  
Li-Na Wang ◽  
Hong-Mei Yin ◽  
Heng-Wei Zhou ◽  
Yi-Neng Huang

2005 ◽  
Vol 122 (12) ◽  
pp. 124510 ◽  
Author(s):  
Dirk Woywod ◽  
Sebastian Schemmel ◽  
Gernot Rother ◽  
Gerhard H. Findenegg ◽  
Martin Schoen

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Aleksandra Drozd-Rzoska

Abstract In pressurized glass-forming systems, the apparent (changeable) activation volume Va(P) is the key property governing the previtreous behavior of the structural relaxation time (τ) or viscosity (η), following the Super-Barus behavior: $${\boldsymbol{\tau }}{\boldsymbol{(}}{\boldsymbol{P}}{\boldsymbol{)}}{\boldsymbol{,}}{\boldsymbol{\eta }}{\boldsymbol{(}}{\boldsymbol{P}}{\boldsymbol{)}}{\boldsymbol{\propto }}{\bf{\exp }}{\boldsymbol{(}}{{\boldsymbol{V}}}_{{\boldsymbol{a}}}{\boldsymbol{(}}{\boldsymbol{P}}{\boldsymbol{)}}{\boldsymbol{/}}{\boldsymbol{R}}{\boldsymbol{T}}{\boldsymbol{)}}$$ τ ( P ) , η ( P ) ∝ exp ( V a ( P ) / R T ) , T = const. It is usually assumed that Va(P) = V#(P), where $${{\boldsymbol{V}}}^{{\boldsymbol{\#}}}{\boldsymbol{(}}{\boldsymbol{P}}{\boldsymbol{)}}={\boldsymbol{R}}{\boldsymbol{T}}{\boldsymbol{d}}\,{\boldsymbol{ln}}\,{\boldsymbol{\tau }}{\boldsymbol{(}}{\boldsymbol{P}}{\boldsymbol{)}}{\boldsymbol{/}}{\boldsymbol{d}}{\boldsymbol{P}}$$ V # ( P ) = R T d ln τ ( P ) / d P or $${{\boldsymbol{V}}}^{{\boldsymbol{\#}}}{\boldsymbol{(}}{\boldsymbol{P}}{\boldsymbol{)}}{\boldsymbol{=}}{\boldsymbol{R}}{\boldsymbol{T}}{\boldsymbol{d}}\,{\boldsymbol{ln}}\,{\boldsymbol{\eta }}{\boldsymbol{(}}{\boldsymbol{P}}{\boldsymbol{)}}{\boldsymbol{/}}{\boldsymbol{d}}{\boldsymbol{P}}$$ V # ( P ) = R T d ln η ( P ) / d P . This report shows that Va(P) ≪ V#(P) for P → Pg, where Pg denotes the glass pressure, and the magnitude V#(P) is coupled to the pressure steepness index (the apparent fragility). V#(P) and Va(P) coincides only for the basic Barus dynamics, where Va(P) = Va = const in the given pressure domain, or for P → 0. The simple and non-biased way of determining Va(P) and the relation for its parameterization are proposed. The derived relation resembles Murnaghan - O’Connel equation, applied in deep Earth studies. It also offers a possibility of estimating the pressure and volume at the absolute stability limit. The application of the methodology is shown for diisobutyl phthalate (DIIP, low-molecular-weight liquid), isooctyloxycyanobiphenyl (8*OCB, liquid crystal) and bisphenol A/epichlorohydrin (EPON 828, epoxy resin), respectively.


1988 ◽  
Vol 153-155 ◽  
pp. 1287-1288 ◽  
Author(s):  
D.M. Newns ◽  
P. Pattnaik ◽  
M. Rasolt ◽  
D.A. Papaconstantopolous
Keyword(s):  

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