Isotope effects on the dynamics of amorphous ices and aqueous phosphoric acid solutions

文献情報

出版日 2022-06-14

DOI 10.1039/D2CP01455F

インパクトファクター 3.676

著者

C. M. Tonauer, T. Loerting

原文を見る

要旨

The glass transitions of amorphous ices as well as of aqueous phosphoric acid solutions were reported to display very large 1H/2H isotope effects. Using dielectric spectroscopy, in both types of glassformers for equimolar protonated/deuterated mixtures an almost ideal isotope-mixing behavior rather than a bimodal relaxation is found. For the amorphous ices this finding is interpreted in terms of a glass-to-liquid rather than an orientational glass transition scenario. Based on calorimetric results revealing that major 16O/18O isotope effects are missing, the latter scenario was previously favored for the amorphous ices. Considering the dielectric results on 18O substituted amorphous ices and by comparison with corresponding results for the aqueous phosphoric acid solutions, it is argued that the present findings are compatible with the glass-to-liquid scenario. To provide additional information regarding the deeply supercooled state of 1H/2H isotopically mixed and 18O substituted glassformers, the aqueous phosphoric acid solutions are studied using shear mechanical spectroscopy as well, a technique which so far could not successfully be applied to characterize the glass transitions of the amorphous ices.

掲載誌

Physical Chemistry Chemical Physics

CiteScore: 5.5

自己引用率: 10.3%

年間論文数: 3036

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