Journal article

Effects of charge double layer and colloidal aggregation on the isotropic-nematic transition of protein fibers in water

  • Mezzenga, Raffaele ETH Zurich, Food & Soft Materials Science, Institute of Food, Nutrition & Health, Zürich, Switzerland
  • Jung, Jin-Mi Department of Physics and Fribourg Center for Nanomaterials, University of Fribourg, Switzerland
  • Adamcik, Jozef ETH Zurich, Food & Soft Materials Science, Institute of Food, Nutrition & Health, Zürich, Switzerland
    28.05.2010
Published in:
  • Langmuir. - 2010, vol. 26, no. 13, p. 10401–10405
English We investigate the effects of variable linear charge density and Debye length on the mesoscopic properties of β-lactoglobulin fibers in water, by changing the pH and ionic strength, respectively. We determine the isotropic−nematic (I−N) transition by cross-polarized microscopy and quantify by atomic force microscopy the increasing tendency of the fibers to aggregate upon raising ionic strength. We then compare experimental I−N transitions with theoretical expected values based on Onsager theory. Unlike previous reports on lyotropic liquid crystalline behavior of protein fibers, we show that, if double layer effects and aggregation of fibers are correctly included directly in the second virial coefficient and excluded volume, Onsager theory accurately predicts the experimental I−N transition versus pH and ionic strength.
Faculty
Faculté des sciences et de médecine
Department
Département de Physique
Language
  • English
Classification
Chemistry
License
License undefined
Identifiers
Persistent URL
https://folia.unifr.ch/unifr/documents/301712
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