Spreading of nanofluids on solids

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Revision as of 20:49, 4 December 2009 by Chakraborty (Talk | contribs) (New page: ==Reference== Wasan, D.T., Nikolov, A.D., Nature 423 (2003). ==Keywords== adhesion, spreading, disjoining pressure ==Summary== [[Image:Ion_dist_graph.jpg |right| |300px| |thumb| Figure ...)

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Reference

Wasan, D.T., Nikolov, A.D., Nature 423 (2003).

Keywords

adhesion, spreading, disjoining pressure

Summary

Figure 1. X-ray reflectivity versus wave vector transfer <math>Q_z</math> from interface between a 0.01 M solution of TBATPB in nitrobenzeneand a solution of TBABr in water at five concentrations(0.01, 0.04, 0.05, 0.057, 0.08 M, bottom to top). Solid lines are prediction using MD simulations for potential of mean force, and dashed lines are predicted by the Gouy-Chapman model.

The authors of the paper study adhesion and spreading of suspensions of nanometer-size particles, or nanofluids. When a gas bubble dispersed in an aqueous nanofluid approaches a smooth hydrophilic solid surface, a microscopic transition exists between the liquid film and the meniscus. This transition region has a wedge-like profile, and the nanofluid film can change in steps inside this region. The aim of the paper is to find how structural disjoining pressure affects the spreading of colliodal fluids on solid surfaces.

In the first experiment, a wedge-film was formed by blowing an air bubble (diameter 200um) against a smooth glass plate in a suspension of 1um-latex spheres. The volume fraction of latex spheres was 7%. It was found that the latex particles form a 2D colliod crystal at a thickness of the wedge film equal to twice the particle diameter, but the structure changes to a disordered structure when the film grows in excess of three particle diameters.