Category: Transient Plane Source
Keywords: Carbon nanotubes, CNTs, Energy Dispersive X-Ray Analysis, Heat Transfer Coolants, Lubricants, magnetic field, nanocomposites, Scanning Electron Microscopy, Scanning Electron Microscopy (SEM), SEM, sonication, TEM, Thermal Conductivity, Transmission electron microscopy, Transmission electron microscopy (TEM), viscosity
Abstract: Ni-coated single-walled carbon nanotubes (SWNTs) were dispersed in four fluids (of varying viscosities) to create four different nanofluids. Due to the magnetic properties of the coated nanotubes the researchers induced a magnetic field to increase the thermal conductivity of the nanofluids. The increase in thermal conductivity was due to the alignment of the carbon nanotubes into chains due to the magnetic field. A Hot Disk Thermal Constants Analyzer was used to measure the thermal conductivity, and SEM and TEM were used to characterize the physical properties of the magnetically stimulated nanofluids. The greatest increase in thermal conductivity was seen with the use of water as a carrier fluid and its value increased from 0.63 W/mK to 1.10 W/mK through the use of a magnetic field. The lower the viscosity of the carrier fluid used, the higher the thermal conductivity during magnetic stimulation. The thermal conductivity peaked after exposure to the magnetic field for 4 minutes and then subsequently decreased after the 4 minute mark.
Reference: Journal of Applied Physics, 107 (2010) 104320