Empirical and Theoretical Models of Equilibrium and Non-Equilibrium Transition Temperatures of Supplemented Phase Diagrams in Aqueous Systems

Corti, Horacio R.; Angell, C. Austen; Auffret, Tony; Levine, Harry; Buera, M. Pilar; Reid, David; Roos, Yrjö H.; Slade, Louise

doi:10.1515/iupac.82.0029

Cited by 8 publications

(13 citation statements)

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“…Note that the effects of plasticizer and BER on the network T g can be separated by comparing the DSC measurements of swollen polyimines with those from DMA measurements with dynamic loading conditions. Various mathematical models have been proposed to capture the T g of swollen polymers, as reviewed recently by Katkov and Levine 54 and Corti et al 55 The most commonly used are the Gordon−Taylor (GT) model and the Couchman−Karasz (CK) model. Specifically, the GT model allows the prediction of T g as a function of the transition temperatures of dry polymer and water.…”

Section: ∑ ∑mentioning

confidence: 99%

Chemomechanics in the Moisture-Induced Malleability of Polyimine-Based Covalent Adaptable Networks

et al. 2018

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The moisture-induced malleability of polyimine-based covalent adaptable networks (CANs) enables the thermosets to be reprocessed and recycled at ambient temperature using only water, which leads to an energy-neutral green processing of the materials. This paper provides both experimental and theoretical studies to understand the effects of temperature and moisture content on the kinetics of bond exchange reactions (BERs), malleability, in situ softening, and damping effects of polyimine-based CANs. The study shows that the temperature and moisture content are equivalent in affecting the time scale of network stress relaxation. A time–temperature–moisture superposition principle is therefore established. The modeling theory identifies the critical thicknesses when the network relaxation is dominated by the moisture diffusion or the intrinsic BER kinetics. It also probes the transition region of polyimine CANs underwater, in which the glassy solid samples gradually transform into the malleable state with an enhanced damping ratio.

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Section: ∑ ∑mentioning

confidence: 99%

Chemomechanics in the Moisture-Induced Malleability of Polyimine-Based Covalent Adaptable Networks

et al. 2018

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“…In relatively dilute frozen solutions of PHC, hexagonal ice coexists with the freeze-concentrated solution consisting of the solute and unfrozen water, with the water content in the freeze concentrate ranging typically from approximately 30 to 15 wt %. 8,9 On the other hand, in solutions with a high concentration of PHC (typically above 70 wt %), ice does not form at all, and the system remains in a single-phase amorphous state.…”

Section: ■ Introductionmentioning

confidence: 99%

Water in a Soft Confinement: Structure of Water in Amorphous Sorbitol

Shalaev

Soper

2016

J. Phys. Chem. B

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The structure of water in 70 wt % sorbitol-30 wt % water mixture is investigated by wide-angle neutron scattering (WANS) as a function of temperature. WANS data are analyzed using empirical potential structure refinement to obtain the site-site radial distribution functions (RDFs). Orientational structure of water is represented using OW-OW-OW triangles distributions and a tetrahedrality parameter, q, while water-water correlation function is used to estimate size of water clusters. Water structure in the sorbitol matrix is compared with that of water confined in nanopores of MCM41. The results indicate the existence of voids in the sorbitol matrix with the length scale of approximately 5 Å, which are filled by water. At 298 K, positional water structure in these voids is similar to that of water in MCM41, whereas there is a difference in the tetrahedral (orientational) arrangement. Cooling to 213 K strengthens tetrahedrality, with the orientational order of water in sorbitol becoming similar to that of confined water in MCM41 at 210 K, whereas further cooling to 100 K does not introduce any additional changes in the tetrahedrality. The results obtained allow us to propose, for the first time, that such confinement of water in a sorbitol matrix is the main reason for the lack of ice formation in this system.

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“…4−9 State diagrams are supplemented phase diagrams that show the binary phase diagram of a water−solute system supplemented with data of amorphous states formed by the water−solute system. 33 Although a ternary and particularly a frozen or cryopreserved system may have a simple composition of a purified protein, cryoprotectant carbohydrate, and water, the system becomes freeze-concentrated at low temperatures with a resultant complex distribution of ice and unfrozen water within amorphous components. The present study provided for the first time data that could be used to establish a ternary state diagram for a composite aqueous carbohydrate−protein system.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Quantification of Protein Hydration, Glass Transitions, and Structural Relaxations of Aqueous Protein and Carbohydrate–Protein Systems

Roos

Potes

2015

J. Phys. Chem. B

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Water distribution and miscibility of carbohydrate and protein components in biological materials and their structural contributions in concentrated solids are poorly understood. In the present study, structural relaxations and a glass transition of protein hydration water and antiplasticization of the hydration water at low temperatures were measured using dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) for bovine whey protein (BWP), aqueous glucose-fructose (GF), and their mixture. Thermal transitions of α-lactalbumin and β-lactoglobulin components of BWP included water-content-dependent endothermic but reversible dehydration and denaturation, and exothermic and irreversible aggregation. An α-relaxation assigned to hydration water in BWP appeared at water-content-dependent temperatures and increased to over the range of 150-200 K at decreasing water content and in the presence of GF. Two separate glass transitions and individual fractions of unfrozen water of ternary GF-BWP-water systems contributed to uncoupled α-relaxations, suggesting different roles of protein hydration water and carbohydrate vitrification in concentrated solids during freezing and dehydration. Hydration water in the BWP fraction of GF-BWP systems was derived from equilibrium water sorption and glass transition data of the GF fraction, which gave a significant universal method to quantify (i) protein hydration water and (ii) the unfrozen water in protein-carbohydrate systems for such applications as cryopreservation, freezing, lyophilization, and dehydration of biological materials. A ternary supplemented phase diagram (state diagram) established for the GF-BWP-water system can be used for the analysis of the water distribution across carbohydrate and protein components in such applications.

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Empirical and Theoretical Models of Equilibrium and Non-Equilibrium Transition Temperatures of Supplemented Phase Diagrams in Aqueous Systems

Cited by 8 publications

References 0 publications

Chemomechanics in the Moisture-Induced Malleability of Polyimine-Based Covalent Adaptable Networks

Chemomechanics in the Moisture-Induced Malleability of Polyimine-Based Covalent Adaptable Networks

Water in a Soft Confinement: Structure of Water in Amorphous Sorbitol

Quantification of Protein Hydration, Glass Transitions, and Structural Relaxations of Aqueous Protein and Carbohydrate–Protein Systems

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