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Your search keyword '"polyhydric alcohols"' showing total 5 results
Start Over Descriptor "polyhydric alcohols" Topic glycerol
5 results on '"polyhydric alcohols"'

1. Stabilizing MXene suspension with polyhydric alcohols.

Author

Cheng, Renfei, Wang, Junchao, Hu, Tao, Zhao, Yiming, Liang, Yan, Wang, Xiaohui, and Zhou, Yanchun

Subjects
DISSOLVED oxygen in water, ETHYLENE glycol, ALCOHOL, MOLECULAR dynamics
Abstract

• A simple yet efficient strategy for long term storage of MXene suspension by introducing glycerol, a typical polyhydric alcohol, was developed. • The effectiveness of the strategy is evidenced by structural compositional and morphological investigations. • Glycerol protects the defective sites of MXene flakes through restricting water and/or oxygen molecules from reactive sites. • The strategy based on polyhydric alcohols has the potential to be extended to other MXenes, solving the most urgent challenge in the field of MXene engineering. MXenes have promises in myriad applications by virtue of two-dimensional nature and adjustable functional groups. To achieve the applications, MXenes are always first prepared in the form of aqueous suspension. However, fast degradation caused by the attack of dissolved oxygen and water molecules is the main obstacle to the application of MXenes. It has come to light that the degradation preferentially takes place at defective sites and edges where defects enrich. To tackle this problem and increase the stability, herein, using Ti 3 C 2 T x MXene as a model material, we report a simple yet efficient strategy for long term storage of MXene suspension by introducing glycerol, a typical polyhydric alcohol. The effectiveness of the strategy is evidenced by structural compositional and morphological investigations. Glycerol protects the defective sites of MXene flakes through restricting water and/or oxygen molecules from reactive sites. This is supported by ab initio molecular dynamics simulations that form hydrogen bonds between MXene and glycerol molecules just over defective sites. Following this mechanism, other polyhydric alcohols, such as ethylene glycol and propylene glycol, are also effective in stabilizing Ti 3 C 2 T x MXene suspension. The strategy based on polyhydric alcohols has the potential to be extended to other MXenes, solving the most urgent challenge in the field of MXene engineering. [Display omitted] [ABSTRACT FROM AUTHOR]

Published
2023
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2. Radiolysis of Polyol Solutions: Molecular Products—Spectral Doubles of Malondialdehyde.

Author

Lyutova, Zh. B., Panasyuk, S. L., and Yudin, I. V.

Subjects
*RADIOLYSIS, *UNSATURATED compounds, *CARBONYL compounds, *MALONDIALDEHYDE, *ANALYTICAL chemistry, *POLYOLS
Abstract

The formation of unsaturated carbonyl compounds in irradiated aqueous solutions of polyhydric alcohols has been studied using spectrophotometry, HPLC, and chemical analysis. Some spectral characteristics of these products have been determined, and they almost coincide with those calculated according to Woodward–Fieser rules. [ABSTRACT FROM AUTHOR]

Published
2020
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3. To the organic world: carbon.

Author

Cotterill, Rodney

Abstract

'tis, we musicians know, the C Major of this life. Paintings and museum reconstructions depicting the activities of medieval alchemists can easily give the wrong impression of the chemical knowledge of that period. Inanimate objects such as crystals are seen sharing shelves with the preserved bodies of small creatures, a common feature of the early laboratory. This could be taken to suggest that the scientists of those days had grasped the unity of chemistry: that in spite of great differences in their external appearance, Nature makes no distinction between chemical combinations in living and dead substances. Nothing could be farther from the truth. The universally held belief was that the matter contained in living organisms possessed an essential extra ingredient, a vital force, the mysterious origin of which was attributable to divine powers. This attitude was epitomized in the succinct classification to be found in the book Cours de Chyme, published by Nicholas Lemery in 1685. His division is still to be found in the standard first question of a popular parlour game: ‘animal, vegetable or mineral?’. By the end of the eighteenth century, the vital force theory was in rapid decline. Antoine Lavoisier, analyzing typical organic compounds, found them to contain inorganic substances such as hydrogen, oxygen, nitrogen, carbon, sulphur and phosphorus. The basic principles that govern chemical change, such as conservation of total mass, were being established during this period, and in 1844 Jöns Berzelius showed that they apply to all matter irrespective of whether it is inorganic or organic. [ABSTRACT FROM AUTHOR]

Published
2008
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4. Polyhydric alcohol production and intracellular amino acid pool in relation to halotolerance of the yeast Debaryomyces hansenii.

Author

Adler, L. and Gustafsson, Lena

Abstract

Changes in polyol production and the intracellular amino acid pool were followed during the growth cycle of Debaryomyces hansenii in 4 mM and 2.7 M NaCl media. The intracellular levels of polyols were markedly enhanced by high salinity, the dominant solutes being glycerol in log phase cells and arabinitol in stationary phase cells. At low salinity arabinitol was the most prominent intracellular solute throughout the growth cycle. There were no major changes in the composition of the total amino acid pool with changes in cultural salinity. The amount of total free amino acids related to cell dry weight was 15-50% lower in cells cultured in 2.7 M NaCl as compared to 4 mM NaCl media. After subtraction of contributions from intracellular polyols the calculated cellular C/N ratio was found to be unaffected by cultural age and salinity during the late log and early stationary phase. On prolonged incubation of stationary phase cells, this ratio decreased, particularly at high salinity. The sensitivity of cells towards exposure to high salinity was measured in terms of the length of the lag phase after transference to 2.7 M NaCl media. This lag phase decreased with increasing intracellular polyol concentrations. At a given polyol content, stationary phase cells were considerably less sensitive than were log phase cells. When cultured at high salinity the mutant strain, 26-2b, grew more slowly and retained less of the total polyol produced during the early growth stages than did the wildtype. Exogenously supplied mannitol, arabinitol, and glycerol stimulated the growth of the mutant in saline media. Erythritol was without effect. [ABSTRACT FROM AUTHOR]

Published
1980
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