The surfactant effect of drying patterns of water and nanofluid droplets
Tay, Xiang Lan
Date of Issue2016-05-23
School of Mechanical and Aerospace Engineering
The drying patterns of nanofluids strongly influence the use of nanofluids in the different fields particularly the microchip manufacturing and ink jet printing with nanoparticles. Past researches show a lack of information in the autophobic effect of nanofluid droplets. Thus, the present experimental study investigates the effect of surfactant on drying patterns of nanofluid droplet. It will be conducted through the drying of droplets with different concentration Hexadecyltrimethylammonium bromide (CTAB) surfactant in pure water as well as in nanofluid. The experiment studies the variations in drying patterns of droplets by comparing the radius before and after evaporation as well as analyzing the deposition of elements present through the use of a Scanning Electron Microscope with EDX. The behavior of CTAB in pure De-ionized (DI) water will first be analyzed. CTAB solution prepared consists of CTAB powder added to 40g of DI water. 7 concentrations of CTAB solution are used in this study ranging from 0.0005% to 0.05%. All experiments will be carried out with placing 1.0μL droplet on silicon wafer. Graphite nanoparticles and different amount of CTAB powder will then be added to 40g DI water to form different concentration CTAB in 1g/L of Nanofluid. Results suggest that the rate of change of radius decreases with increasing concentration of CTAB used in the absence of nanoparticles. The decreasing rate of change of radius is attributed to the increased in wettability when a higher concentration of CTAB used. This phenomenon is not seen when adding nanoparticles. The effect of CTAB in reducing radius of droplet is insignificant, thus concluding that the effect of nanoparticles triumphed over the effect of CTAB in the drying patterns of a nanofluid droplet. Further studies such as using different type of surfactants and nanoparticles can be done to broaden the scope of study.
Final Year Project (FYP)
Nanyang Technological University