Influence of solvents on the enhancement of thermophysical properties and stability of multi-walled carbon nanotubes nanofluid

Abstract

Multi-walled carbon nanotubes (MWCNTs) are a contemporary class of nanoparticles that have a prominent thermal, electrical and mechanical properties. There have been numerous studies on the enhancement of thermophysical properties of nanofluids. However, there is only limited research on thermal and stability analysis of MWCNT nanofluids with various kinds of solvents or base fluids, namely propylene glycol, ethanol, ethylene glycol, polyethylene glycol, methanol and water. This paper reports the enhancement of thermophysical properties and stability of MWCNTs with six different base fluids in the presence of sodium dodecyl benzene sulfonate surfactant with a mass concentration of 0.5 wt%. Thermal and dispersion stabilities were determined using a thermogravimetric analyzer (TGA) and Zeta potential, along with a visual inspection method to evaluate the agglomeration or sedimentation of MWCNT nanoparticles over a period of one month. Ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy were utilized to identify the molecular components and light absorption of the formulated nanofluids at their maximum wavenumber (4500 cm −1 ) and wavelength (800 nm). In addition, thermophysical properties such as thermal conductivity, specific heat capacity, viscosity and density with a peak temperature of 200 °C were also experimentally evaluated. The TGA results illustrated that MWCNT/ethylene glycol nanofluid achieved maximum thermal stability at 140 °C and it revealed a maximum zeta potential value of −61.8 mV. Thus, ethylene glycol solution was found to be the best base liquid to homogenize with MWCNTs for acquiring an enhanced thermophysical property and a long-term stability.

Optimization of Thermophysical and Rheological Properties of Mxene Ionanofluids for Hybrid Solar Photovoltaic/Thermal Systems

“…Figure 11 depicts the specific heat capacity of the proposed fluid at certain temperatures. From the experimental values, a significant increase in the specific heat capacity of the ionanofluids was observed with increase in temperature which is consistent with many of the literature on various types of nanofluids [45,46]. This implies that temperature has a significant effect on the specific heat capacity enhancement of ionanofluids, mainly due to the high surface energy of MXene nanoparticles that can be applied to high-temperature applications where more absorption of heat is desired.…”

Artificial Neural Network Technique for Estimating the Thermo-Physical Properties of Water-Alumina Nanofluid

“…Mass of nano particles required to prepare the required concentration of the nanofluid was determined using the eqn. (2). The quantity of the Al 2 O 3 nano powder required for the preparation of various concentrations of the nanofluid was as shown in Table 1.…”

Heat Transfer Rate Optimisation of Ionanofluid Based Heat Sink Using ANSYS

“…In accordance with the FESEM image, the presence of wrinkled walls, irregular nano lobes, kinks and some sidewall breakages revealed the defect formations. More detailed analysis of the studied MWCNT nanoparticles was recorded in our previous literature [37].…”