Pronounced micro-segregation in a sorbitol water mixture observed through variable temperature neutron scattering

Published

May 16, 2012

Author(s)

Shin G. Chou, Sheila Khodadadi, Joseph E. Curtis, Susan Krueger, Evgenyi Shalaev, Alan Soper, Andy Fitch, T Narayanan, Michael Szutucki, Marcus T. Cicerone

Abstract

In this study, we use small and wide angle X-ray and neutron scattering measurements, to study the structure of concentrated sorbitol solutions and glasses at different temperatures. The analysis of the data suggests the water forms clusters with a structure resembling the low-density amorphous ice. Large-scale were detected by both small-angle X-ray and neutron measurements at lower temperatures. The observed inhomogeneities suggest areas with well-defined interfaces, potentially indicative of molecular segregation on the length scale of tens nms, although neither water nor sorbitol crystallization was observed. The local structure was similar over the entire temperature range studied, from 100K to 300K. Therefore, the appearance of larger (tens of nm) segregated structures at lower temperatures is likely due to coalescence of smaller "clusters" of water and sorbitol, without any significant structural changes on the smaller length scale. Potential practical implications of these findings to cryopreservation and properties of amorphous pharmaceuticals are discussed.

Citation

Journal of Physical Chemistry B

Volume

116

Issue

15

Pub Type

Journals

Keywords

biophysics, neutrons, polymer, sugar

Citation

Chou, S. , Khodadadi, S. , Curtis, J. , Krueger, S. , Shalaev, E. , Soper, A. , Fitch, A. , Narayanan, T. , Szutucki, M. and Cicerone, M. (2012), Pronounced micro-segregation in a sorbitol water mixture observed through variable temperature neutron scattering, Journal of Physical Chemistry B (Accessed April 24, 2024)