University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Magnetic-resonance determination of the spatial dependence of the droplet size distribution in the cream layer of oil-in-water emulsions: Evidence for the effects of depletion flocculation

McDonald, PJ, Ciampi, E, Keddie, JL, Heidenreich, M and Kimmich, R (1999) Magnetic-resonance determination of the spatial dependence of the droplet size distribution in the cream layer of oil-in-water emulsions: Evidence for the effects of depletion flocculation Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, 59 (1). 874 - 884. ISSN 1063-651X

[img]
Preview
PDF
McDonald-PhysRevE.59.874.pdf
Available under License : See the attached licence file.

Download (248kB)
[img]
Preview
PDF (licence)
SRI_deposit_agreement.pdf

Download (33kB)

Abstract

It is shown that a combination of pulsed-field-gradient spin-echo ~PGSE! nuclear-magnetic-resonance~NMR! restricted diffusion analysis and NMR imaging may be used to measure the spatial dependence of the droplet size distribution in the cream layer of turbid oil-in-water emulsions. 1H-13C cyclic J cross-polarization PGSE is introduced as a technique for this purpose in cases where selective observation of the oil component ~or other carbohydrate constituent! is required. With this method, 13C nuclei are chemical shift selectively excited by cross-polarization from coupled 1H partners. An optimum detection sensitivity is ensured by transferring the polarization back to the coupled protons with which the combined imaging and diffusion experiment is then carried out. The spatial dependence of the oil droplet size distribution was measured for a series of emulsions containing various fractions of gum xanthan thickener dissolved in the water. The experimental results are compared with a recent model of the creaming process due to Pinfield, Dickinson, and Povey @J. Colloid Interface Sci. 166, 363 ~1994!#. When no gum xanthan is present, the experimental results are in good agreement with the model. However, the model fails to describe the droplet distribution for emulsions with a gum xanthan concentration of the order of 0.1 wt %. The discrepancy is discussed in terms of depletion flocculation and depletion stabilization.

Item Type: Article
Additional Information: © 1999 The American Physical Society
Divisions: Faculty of Engineering and Physical Sciences > Physics
Depositing User: Symplectic Elements
Date Deposited: 14 Mar 2012 11:21
Last Modified: 23 Sep 2013 19:05
URI: http://epubs.surrey.ac.uk/id/eprint/164608

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year


Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800