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Influence of particle composition and thermal cycling on bijel formation

White, K. A.; Schofield, A. B.; Binks, B. P.; Clegg, P. S.

Authors

K. A. White

A. B. Schofield

P. S. Clegg

Abstract

Colloidal particles with appropriate wetting properties can become very strongly trapped at an interface between two immiscible fluids. We have harnessed this phenomenon to create a new class of soft materials with intriguing and potentially useful characteristics. The material is known as a bijel: bicontinuous interfacially-jammed emulsion gel. It is a colloid-stabilized emulsion with fluid-bicontinuous domains. The potential to create these gels was first predicted using computer simulations. Experimentally we use mixtures of water and 2,6-lutidine at the composition for which the system undergoes a critical demixing transition on warming. Colloidal silica, with appropriate surface chemistry, is dispersed while the system is in the single-fluid phase; the composite sample is then slowly warmed well beyond the critical temperature. The liquids phase separate via spinodal decomposition and the particles become swept up on the newly created interfaces. As the domains coarsen the interfacial area decreases and the particles eventually become jammed together. The resulting structures have a significant yield stress and are stable for many months. Here we begin to explore the complex wetting properties of fluorescently tagged silica surfaces in water-lutidine mixtures, showing how they can be tuned to allow bijel creation. Additionally we demonstrate how the particle properties change with time while they are immersed in the solvents.

Journal Article Type Article
Publication Date Dec 10, 2008
Journal JOURNAL OF PHYSICS-CONDENSED MATTER
Print ISSN 0953-8984
Electronic ISSN 1361-648X
Publisher IOP Publishing
Peer Reviewed Peer Reviewed
Volume 20
Issue 49
Article Number ARTN 494223
Institution Citation White, K. A., Schofield, A. B., Binks, B. P., & Clegg, P. S. (2008). Influence of particle composition and thermal cycling on bijel formation. Journal of physics. an Institute of Physics journal. Condensed matter, 20(49), doi:10.1088/0953-8984/20/49/494223
DOI https://doi.org/10.1088/0953-8984/20/49/494223
Keywords General Materials Science; Condensed Matter Physics
Publisher URL http://iopscience.iop.org/article/10.1088/0953-8984/20/49/494223/meta