Evaporation of Fe3O4 nanofluids

• Main Author: Teo, Wei Ming
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Nanotechnology
• Online Access: http://hdl.handle.net/10356/60457
• Institution: Nanyang Technological University

Nanofluid is a liquid that contains suspensions of nanoparticles and has been widely established and used in the past decade. As an effective heat transfer fluid due to its enhanced thermal properties, it is commonly found in the automotive and electrical industries as coolants [1]and is a significant breakthrough for nanotechnology. This study would discuss the experimental results of the evaporation of Iron Oxide (Fe3O4) nanofluid. It aims to facilitate the understanding of the underlying factors affecting the evaporation rate. Three main studies were conducted. Firstly, was the effects of varying concentrations of Hexadecyltrimethylammonium bromide (CTAB); 0%, 0.01%, 0.03% and 0.05%. Next, was the effects of varying concentrations of Fe3O4; 0g/l, 1g/l, 3g/l and 5g/l. Lastly, it was the use of different substrate surface; silicon wafer, glass slide and Polymethyl methacrylate (PMMA) for the evaporation of the droplet nanofluid to take place on. The first experiment showed that the surface tension decreased proportionately to the increase in concentration of CTAB, indicating that the main function of CTAB is to decrease the surface tension of the droplet. This is supported in the dry-out pattern, where the contact line width thickened, given the increase in CTAB concentration. In the second experiment, it was concluded the main function of Fe3O4 is to improve the wettability dynamics of the droplet, since the droplet receded faster with the increase in Fe3O4 concentration. Finally, the last experiment illustrated that the droplet evaporated faster on the hydrophilic substrate surface as there is more contact between the both i.e. better wettability. Past research conducted have proven that droplet with contact angle smaller than 90° follows an evaporation behaviour; that the contact line is anchored and weight loss induced by evaporation is linear with time of the mass. As the above experiments are mostly targeted at the thermal properties of nanofluid, future works can be done to conduct studies on the magnetic properties of Fe3O4 as it could be a significant factor for improving the evaporation of the nanofluid.