Dextran‐Based Polycations: Thermodynamic Interaction with Water as Compared With Unsubstituted Dextran, 2 – Flory/Huggins Interaction Parameter

Bercea, Maria; Nichifor, Marieta; Eckelt, John; Wolf, Bernhard

doi:10.1002/macp.201100197

Cited by 18 publications

(27 citation statements)

References 14 publications

(22 reference statements)

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“…We have observed that it required a longer time (∼14 days) for the PAA-EICP solution to completely dry compared with pure EICP solutions . Vapor pressure − measurement showed that adding PAA into DI water could significantly lower the evaporation rate (Figure S2a). The interactions between PAA and water molecules were energetically favorable, which was attributed to the carboxyl rich, super hydrophilic structure of PAA (Figure S2b).…”

Section: Resultsmentioning

confidence: 98%

Biomimetic Hydrogel Composites for Soil Stabilization and Contaminant Mitigation

Zhao

Hamdan

Shen

et al. 2016

Environ. Sci. Technol.

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We have developed a novel method to synthesize a hyper-branched biomimetic hydrogel network across a soil matrix to improve the mechanical strength of the loose soil and simultaneously mitigate potential contamination due to excessive ammonium. This method successfully yielded a hierarchical structure that possesses the water retention, ion absorption, and soil aggregation capabilities of plant root systems in a chemically controllable manner. Inspired by the robust organic-inorganic composites found in many living organisms, we have combined this hydrogel network with a calcite biomineralization process to stabilize soil. Our experiments demonstrate that poly(acrylic acid) (PAA) can work synergistically with enzyme-induced carbonate precipitation (EICP) to render a versatile, high-performance soil stabilization method. PAA-enhanced EICP provides multiple benefits including lengthening of water supply time, localization of cementation reactions, reduction of harmful byproduct ammonium, and achievement of ultrahigh soil strength. Soil crusts we have obtained can sustain up to 4.8 × 10 kPa pressure, a level comparable to cementitious materials. An ammonium removal rate of 96% has also been achieved. These results demonstrate the potential for hydrogel-assisted EICP to provide effective soil improvement and ammonium mitigation for wind erosion control and other applications.

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Section: Resultsmentioning

confidence: 98%

Biomimetic Hydrogel Composites for Soil Stabilization and Contaminant Mitigation

Zhao

Hamdan

Shen

et al. 2016

Environ. Sci. Technol.

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“…The derived interaction parameters are χ = 0.47 for D 2 O and χ = 0.05 ± 0.04 for DD-DES, suggesting that although both act as good solvents for PVP, water is closer to a Θ solvent (χ = 0.5) solvent whereas DES approaches the ideal solution limit (i.e., where there are no net effective interactions, χ = 0). The fact that χ is lower for DES, whereas the solubility limit of PVP in DES is also lower, might suggest a concentration dependence of the interaction parameter, − which we do not consider here.…”

Section: Results and Discussionmentioning

confidence: 99%

Properties of Polyvinylpyrrolidone in a Deep Eutectic Solvent

2016

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Deep eutectic solvents (DES) are mixtures of two or more components with high melting temperatures, which form a liquid at room temperature. These DES hold great promise as green solvents for chemical processes, as they are inexpensive and environmentally friendly. Specifically, they present a unique solvating environment to polymers that is different from water. Here, we use small angle neutron scattering to study the polymer properties of the common, water-soluble, polyvinylpyrrolidone (PVP) in the prominent DES formed by a 1:2 molar mixture of choline chloride and urea. We find that the polymer adopts a slightly different structure in DES than in water, so that at higher concentrations the polymer favors a more expanded conformation compared to the same concentration in water. Yet, the osmotic pressure of PVP solutions in DES is very similar to that in water, indicating that both solvents are of comparable quality and that the DES components interact favorably with PVP. The osmotic pressure measurements within this novel class of promising solvents should be of value toward future technological applications as well as for osmotic stress experiments in nonaqueous environments.

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“…[74][75][76][77] This indicates that the limited set of fundamental parameters used in regular solution theory may be insufficient when the solution mixing properties change with concentration, which may prove crucial to making more quantitative predictions. Accounting for concentration-dependent interaction parameters is somewhat analogous to considering MFC parameters that are different in the bulk and the surface domain, thereby establishing different mixing properties in the two domains.…”

Section: Comparing Theory With Protein Folding Experimentsmentioning

confidence: 96%

Macromolecular Stabilization by Excluded Cosolutes: Mean Field Theory of Crowded Solutions

Sapir

Harries

2015

J. Chem. Theory Comput.

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We propose a mean field theory to account for the experimentally determined temperature dependence of protein stabilization that emerges in solutions crowded by preferentially excluded cosolutes. Based on regular solution theory and employing the Flory-Huggins approximation, our model describes cosolutes in terms of their size, and two temperature-dependent microscopic parameters that correspond to macromolecule-cosolute and bulk solution interactions. The theory not only predicts a "depletion force" that can account for the experimentally observed stabilization of protein folding or association in the presence of excluded cosolutes but also predicts the full range of associated entropic and enthalpic components. Remarkably, depending on cosolute identity and in accordance with experiments, the theory describes entropically as well as enthalpically dominated depletion forces, even those disfavored by entropy. This emerging depletion attraction cannot be simply linked to molecular volumes. Instead, the relevant parameter is an effective volume that represents an interplay between solvent, cosolute, and macromolecular interactions. We demonstrate that the apparent depletion free energy is often accompanied by significant yet compensating entropy and enthalpy terms that, although having a net zero contribution to stabilization, can obscure the underlying molecular mechanism. This study underscores the importance of including often-neglected free energy terms that correspond to solvent-cosolute and cosolute-macromolecule interactions, which for most typical cosolutes are expected to be temperature dependent. We propose that experiments specifically aimed at resolving the temperature-dependence of cosolute exclusion from macromolecular surfaces should help reveal the full range of the underlying molecular mechanisms of the depletion force.

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Dextran‐Based Polycations: Thermodynamic Interaction with Water as Compared With Unsubstituted Dextran, 2 – Flory/Huggins Interaction Parameter

Cited by 18 publications

References 14 publications

Biomimetic Hydrogel Composites for Soil Stabilization and Contaminant Mitigation

Biomimetic Hydrogel Composites for Soil Stabilization and Contaminant Mitigation

Properties of Polyvinylpyrrolidone in a Deep Eutectic Solvent

Macromolecular Stabilization by Excluded Cosolutes: Mean Field Theory of Crowded Solutions

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