Open Access

ABSTRACT

Formation of Nanobubbles at the Water-Graphite Interface

by Prabhakar Misra¹, Silvina M. Gatica¹, Obafemi Otelaja²

1 Department of Physics and Astronomy, Howard University, Washington, DC 20059, USA
2 Department of Electrical and Computer Engineering, Howard University, Washington, DC, 0059, USA

The International Conference on Computational & Experimental Engineering and Sciences 2008, 5(4), 205-210. https://doi.org/10.3970/icces.2008.005.205

Abstract

Nanobubbles form either spontaneously or by induction at the surface of certain solids immersed in a liquid. Atomic Force Microscopy observations have confirmed their formation. Such bubbles have sizes in the range 10-100 nm and have important ramifications for properties of interfaces and could be responsible for long-range hydrophobic attractive forces. In addition, as a potential application, the use of nanobubbles -- in tandem with ultrasound -- has been proposed for the treatment of strokes. Formation of nanobubbles at the water-graphite interface influences the adsorption of nanoparticles and the corresponding wetting properties. An important parameter relevant to the stability of the nanobubble is the contact angle, which in turn, depends on the surface tensions of the substrate, liquid and vapor involved at the water-graphite interface through the Young's equation. We have developed a quantitative model that incorporates the attraction of the substrate and allows the determination of the contact angle as a function of temperature. Our computed results compare favorably with the experimental data available in the open literature.

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