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Updated: Jul 10, 2026

Rapid One-step Enzymatic Synthesis and All-aqueous Purification of Trehalose Analogues
09:27

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Published on: February 17, 2017

The slow molecular mobility in amorphous trehalose.

Joaquim J Moura Ramos1, Susana S Pinto, Hermínio P Diogo

  • 1Centro de Química-Física Molecular, Complexo I, IST, TULisbon, Av. Rovisco Pais, 1049-001 Lisboa,, Portugal.

Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry
|October 16, 2007
PubMed
Summary

Molecular mobility in amorphous trehalose was studied using thermally stimulated depolarization currents (TSDC). Aging affects slower molecular motions, suggesting intermolecular interactions, while faster motions remain unchanged.

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Area of Science:

  • Materials Science
  • Physical Chemistry
  • Biophysics

Background:

  • Amorphous trehalose exhibits complex molecular dynamics below its glass transition temperature (T(g)).
  • Understanding these dynamics is crucial for applications involving amorphous solids, such as pharmaceuticals and food science.

Purpose of the Study:

  • To investigate the influence of aging on the sub-T(g) molecular mobility in amorphous trehalose.
  • To differentiate between intramolecular and intermolecular contributions to secondary relaxation processes.

Main Methods:

  • Thermally Stimulated Depolarization Currents (TSDC) technique was employed.
  • Amorphous trehalose samples were aged below the glass transition temperature (T(g) = 115 °C) for varying durations.

Main Results:

  • Two distinct motional components were identified in the secondary relaxation.
  • Faster motional components showed minimal dependence on aging, attributed to intramolecular motions.
  • Slower motional modes exhibited significant aging dependence, indicating local intermolecular motions.
  • The dielectric strength of the slower relaxation decreased with aging time, while relaxation time remained constant.
  • No discernible glass transition signal was observed in the TSDC spectrum around the expected T(g).

Conclusions:

  • Aging primarily impacts intermolecular aspects of molecular mobility in amorphous trehalose.
  • The absence of a clear glass transition signal in TSDC suggests a complex relaxation behavior or limitations of the technique for this specific material.
  • Further studies are needed to fully elucidate the nature of molecular mobility and the glass transition in amorphous trehalose.