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Архив
Proceedings of the 24th National and 2nd International ISHMT-ASTFE Heat and Mass Transfer Conference (IHMTC-2017)


ISBN Онлайн: 978-1-56700-478-6

MEASUREMENT OF SURFACE TENSION AND CONTACT ANGLE OF DIFFERENT NANOFLUIDS: AN EXPERIMENTAL STUDY

DOI: 10.1615/IHMTC-2017.3410
pages 2441-2448

Pritam Kumar Das
Department of Power Engineering, Jadavpur University

Nurul Islam
Department of Power Engineering, Jadavpur University

Khabbab Zakaria
Department of Power Engineering, Jadavpur University

Biswaroop Roy
Department of Power Engineering, Jadavpur University

Apurba Kumar Santra
Department of Power Engineering, Jadavpur University, Salt Lake Campus, Block − LB, Plot-8, Sector — III, Salt Lake, Kolkata — 700 098, India

Ranjan Ganguly
Department of Power Engineering, Jadavpur University Kolkata 700098, India

Аннотация

This paper reports experimentally measured surface tension and contact angle of surfactant-water solutions and surfacted, water-based nanofluids. Nanofluid droplet evaporation has attracted much attention by the researchers due to its wide applications in coating, painting, particle deposition, surface patterning, etc. Stability of the synthesized nanoparticle suspension has been investigated using various surfactants, viz. cetyl trimethyl ammonium bromide (CTAB), acetic acid (AA), oleic acid (OA), sodium dodecyl benzene sulfonate (SDBS), and sodium dodecyl sulfate (SDS), where TiO2-AA, TiO2-CTAB and Al2O3-SDBS are found to provide stable suspensions. Transmission Electron Microscopy (TEM) shows the morphology of the nanofluids, Dynamic light scattering (DLS) indicates the particle size distribution, whereas zeta potential shows the stability of the nanofluids. TiO2-AA, TiO2-CTAB, Al2O3-SDBS, and Al2O3 water based nanofluids have been prepared with different solid volume fractions of 0.1%-2.0%. Apart from this, surfactant-water (AA, CTAB, SDBS) solutions have also been prepared and the results have been compared with those of the surfacted nanofluids to evaluate the effect of surfactants on the nanofluid properties. Surface tension and contact angle of the prepared nanofluids have been measured at room temperature by Du-Nouy ring and sessile droplet methods, respectively. The images obtained using the high-speed camera clearly shows that when a nanofluid droplet impacts a hydrophilic surface (glass substrate) at room temperature, it spreads. Results have shown that contact angle of surfacted-water solutions (without the nanoparticles) are more than the corresponding nanofluids, and the value of contact angle decreases with increase in particle concentration. Surface tension of the prepared suspensions also decreases with increase in particle concentrations.