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Low-temperature dynamics in amorphous polymers and low-molecular-weight glasses—what is the difference?статья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 10 февраля 2016 г.
- Авторы: Eremchev Ivan Yu, Vainer Yury G., Наумов Андрей Витальевич, Kador Lothar
- Журнал: Physical Chemistry Chemical Physics
- Том: 13
- Номер: 5
- Год издания: 2011
- Издательство: Royal Society of Chemistry
- Местоположение издательства: United Kingdom
- Первая страница: 1843
- Последняя страница: 1848
- DOI: 10.1039/c0cp01690j
- Аннотация: Numerous experiments have shown that the low-temperature dynamics of a wide variety of disordered solids is qualitatively universal. However, most of these results were obtained with ensemble-averaging techniques which hide the local parameters of the dynamic processes. We used single-molecule (SM) spectroscopy for direct observation of the dynamic processes in disordered solids with different internal structure and chemical composition. The surprising result is that the dynamics of low-molecular-weight glasses and short-chain polymers does not follow, on a microscopic level, the current concept of low-temperature glass dynamics. An extra contribution to the dynamics was detected causing irreproducible jumps and drifts of the SM spectra on timescales between milliseconds and minutes. In most matrices consisting of small molecules and oligomers, the spectral dynamics was so fast that SM spectra could hardly or not at all be recorded and only irregular fluorescence flares were observed. These results provide new mechanistic insight into the behavior of glasses in general: At low temperatures, the local dynamics of disordered solids is not universal but depends on the structure and chemical composition of the material.
- Добавил в систему: Коновко Андрей Андреевич