The wettability of PTFE and glass surfaces by nanofluids

Rajib Ghosh Chaudhuri; Santanu Paria

doi:10.1016/j.jcis.2014.07.044

The wettability of PTFE and glass surfaces by nanofluids

J Colloid Interface Sci. 2014 Nov 15:434:141-51. doi: 10.1016/j.jcis.2014.07.044. Epub 2014 Aug 9.

Authors

Rajib Ghosh Chaudhuri¹, Santanu Paria²

Affiliations

¹ Interfaces and Nanomaterials Laboratory, Department of Chemical Engineering, National Institute of Technology, Rourkela 769008, Orissa, India.
² Interfaces and Nanomaterials Laboratory, Department of Chemical Engineering, National Institute of Technology, Rourkela 769008, Orissa, India. Electronic address: santanuparia@yahoo.com.

PMID: 25181329
DOI: 10.1016/j.jcis.2014.07.044

Abstract

Wetting of solid surfaces by surfactant solutions is well focused in the literature compared that of nanofluids. Similar to the surfactant solutions nanofluids are also able to reduce the surface tension as well as influence on contact angle at the solid, liquid and gas interface. The surface tension and wettability of two different nanofluids containing hydrophilic (TiO2) and hydrophobic (S) particles have been experimentally studied here. The surface tension reduction of nanofluids strongly depends on material property, particle size and as well as concentration. These parameters also influence the change in contact angle on both hydrophilic (glass) and hydrophobic (PTFE) surfaces. Three important factors such as surface tension, surface hydrophobicity after deposition of particles on a solid surface, and the disjoining pressure influence the final contact angle of nanofluids on a solid surface. Sulfur nanofluids show maximum enhancement in contact angle (30.6°) on the glass surface; on the other hand TiO2 nanofluids show maximum reductions in surface tension (25.4 mN/m) and contact angle on the PTFE surface (17.7°) with respect to pure water.

Keywords: Adhesion tension; Contact angle; Disjoining pressure; Nanofluids; Wetting.