Particle diffusion in globular protein gels in relation to the gel structure
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Updated: Jun 5, 2026

Controlled Synthesis and Fluorescence Tracking of Highly Uniform Poly(N-isopropylacrylamide) Microgels
Published on: September 8, 2016
Gireeshkumar Balakrishnan1, Dominique Durand, Taco Nicolai
1Polymères, Colloïdes, Interfaces, UMR CNRS Université du Maine, Le Mans, France.
Abstract:
Globular protein gels with a variety of structures were prepared by heating β-lactoglobulin solutions at different concentrations and different ionic strengths. The structure was analyzed in terms of the pair correlation function of the protein concentration, and the volume fraction of the gels was determined. A strong coarsening of the gel structure was observed upon increasing the NaCl concentration between 0.1 and 0.25 M. The mean square displacement of spherical particles with diameters between 0.2 and 2 μm was determined in solutions and in gels by multiparticle tracking of confocal laser scanning microscopy images. Brownian diffusion or trapping of spheres with different sizes was observed, depending on the gel structure. In few cases the diffusion was anomalous. The relationship between gel structure and particle mobility is discussed.
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