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Veliyulin, Emil; Voronel, A.; Øye, H. A.

doi:10.1088/0953-8984/7/25/007

Cited by 15 publications

(18 citation statements)

References 13 publications

(1 reference statement)

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“…The characteristic temperature T I is determined as the inflection point in T s c (T ), marking the crossover from the range T g < T < T I , where the product T s c (T ) varies linearly with T 24,25 to the region of higher temperatures T > T I at which the behavior is clearly non-linear. Experimental [26][27][28][29] and simulation 30,31 data for various glass-formers suggest that ∆µ/k B is approximately six times the experimental mode coupling temperature T mc , which is thus identified in our studies with T I . The reported high temperature activation energies ∆µ for segmental relaxation of relatively fragile polymers vary from 12.1 kJ/mol (polybutylene, m = 85) to 17.2 kJ/mol (poly(methyl acrylate), m = 102) and tend to be higher for strong polymers.…”

Section: Introductionsupporting

confidence: 69%

Plasticization and antiplasticization of polymer melts diluted by low molar mass species

Stukalin

Douglas

Freed

2010

The Journal of Chemical Physics

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An analysis of glass formation for polymer melts that are diluted by structured molecular additives is derived by using the generalized entropy theory, which involves a combination of the AdamGibbs model and the direct computation of the configurational entropy based on a lattice model of polymer melts that includes monomer structural effects. Our computations indicate that the plasticization and antiplasticization of polymer melts depend on the molecular properties of the additive. Antiplasticization is accompanied by a "toughening" of the glass mixture relative to the pure polymer, and this effect is found to occur when the diluents are small species with strongly attractive interactions with the polymer matrix. Plasticization leads to a decreased glass transition temperature Tg and a "softening" of the fragile host polymer in the glass state. Plasticization is prompted by small additives with weakly attractive interactions with the polymer matrix. The latter situation can lead to phase separation if the attractive interactions are sufficiently strong. The shifts in Tg of polystyrene diluted by fully flexible short oligomers (up to 20 % mass of diluent) are evaluated from the computations, along with the relative changes in the isothermal compressibility at Tg (a "softening" or "toughing" effect) to characterize the extent to which the additives act as antiplasticizers or plasticizers. The theory predicts that a decreased fragility can accompany both antiplasticization and plasticization of the glass by molecular additives. The general reduction in the Tg and fragility of polymers by these molecular additives is rationalized by analyzing the influence of the diluent's properties (cohesive energy, chain length, and stiffness) on glass formation in diluted polymer melts. The description of glass formation at fixed temperature that is induced upon increasing the diluent concentration directly implies the Angell equation (τα ∼ A exp{B/(φ0, p − φp)}) for the structural relaxation time as function of the polymer concentration, and the computed "zero mobility concentration" φ0, p scales linearly with the inverse polymerization index N .

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Section: Introductionsupporting

confidence: 69%

Plasticization and antiplasticization of polymer melts diluted by low molar mass species

Stukalin

Douglas

Freed

2010

The Journal of Chemical Physics

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“…For example, simulations of both binary Lennard-Jones mixtures (the Kob-Anderson model) 45 and simple models of Lennard-Jones particle chains 46 indicate that ∆µ/k B is approximately six times the experimental 'modecoupling temperature' T mc exp . A large body of data for the viscosity of glass-forming ionic 47,48 and metallic 49,50 melts also supports this approximation, although only a rough correlation with T mc exp is specifically indicated. While the theoretical interpretation of the phenomenological temperature T mc exp is uncertain, 51 it has the well-defined physical significance as a crossover temperature 52,53 separating the high and low-temperature regimes of glass formation, where τ exhibits a qualitatively different (and non-Arrhenius) temperature dependence in each regime.…”

Section: Dependence Of Fragility On Chain Microstructure and Thermody...mentioning

confidence: 89%

“…For example, simulations of both binary Lennard-Jones mixtures (the Kob−Anderson model) and simple models of Lennard-Jones particle chains indicate that Δμ/ k B is approximately six times the experimental ‘mode-coupling temperature' . A large body of data for the viscosity of glass-forming ionic , and metallic , melts also supports this approximation, although only a rough correlation with is specifically indicated.…”

Section: Dependence Of Fragility On Chain Microstructure and Thermody...mentioning

confidence: 93%

Fragility of Glass-Forming Polymer Liquids

2005

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The fragility of polymeric glass-forming liquids is calculated as a function of molecular structural parameters from a generalized entropy theory of polymer glass-formation that combines the Adam-Gibbs (AG) model for the rate of structural relaxation with the lattice cluster theory (LCT) for polymer melt thermodynamics. Our generalized entropy theory predicts the existence of distinct high and low temperature regimes of glass-formation that are separated by a thermodynamically well-defined crossover temperature T(I) at which the product of the configurational entropy and the temperature has an inflection point. Since the predicted temperature dependence of the configurational entropy and structural relaxation time are quite different in these temperature regimes, we introduce separate definitions of fragility for each regime. Experimentally established trends in the fragility of polymer melts with respect to variations in polymer microstructure and pressure are interpreted within our theory in terms of the accompanying changes in the chain packing efficiency.

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“…Currently, the theoretical models of viscosity include Arrhenius empirical equation, Eyring equation, and the simplified polynomial and exponential forms. In order to reduce the effect of error propagation, the viscosity of pure component is fitted by using various fitting equations [22–23,26–27,40–41] . Based on the viscosity of pure component, the viscosities are calculated with Eq.…”

Section: Resultsmentioning

confidence: 99%

“…In order to reduce the effect of error propagation, the viscosity of pure component is fitted by using various fitting equations. [22][23][26][27][40][41] Based on the viscosity of pure compo- nent, the viscosities are calculated with Eq. ( 5), as shown in Figure 2.…”

Section: Propertiesmentioning

confidence: 99%

Design of Refined Quaternary Electrolyte LiF−LiCl−LiBr−LiI Used for the Liquid Metal Battery

Zhao,

Guo,

et al. 2023

ChemPhysChem

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The advanced electrolyte of liquid metal battery should have low melting point, low ionic solubility, low viscosity, high electric and thermal conductivities, and a suitable density between anode and cathode for declining the operating temperature and realizing the goal of saving‐energy. In this study, an excellent quaternary LiF−LiCl−LiBr−LiI (9.1 : 30.0 : 21.7 : 39.2) electrolyte is refined by using thermodynamic models to balance various properties of LiX (X=F, Cl, Br, I) and meet the requirement of advanced electrolyte of liquid metal battery. The refined properties of electrolyte correspond to 2.398 g/cm3 for density, 0.286 mol% for solubility, 4.486 Ohm−1 cm−1 for ionic conductivity, and 0.609 W m−1 for thermal conductivity. The measured melting point is 609.1 K, which is lower than the current operating temperature of 723 K for the lithium‐based liquid metal battery. The refined electrolyte consisted by quaternary halide molten‐salt provides important references for preparing the advanced liquid metal battery.

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Abstract: lnstihltt far Uorganisk Kjemi, N o m Tekniske HBgskole, Universitetet i Tmndheim, N-7034 Tmndheim-NTH, Noway

Cited by 15 publications

References 13 publications

Plasticization and antiplasticization of polymer melts diluted by low molar mass species

Plasticization and antiplasticization of polymer melts diluted by low molar mass species

Fragility of Glass-Forming Polymer Liquids

Design of Refined Quaternary Electrolyte LiF−LiCl−LiBr−LiI Used for the Liquid Metal Battery

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