| Autor: |
Shah SNA; Department of Mechanical Engineering (Main Campus Lahore), University of Engineering, and Technology, Lahore 54890, Pakistan., Shahabuddin S; Department of Science, School of Technology, Pandit Deendayal Energy University, Knowledge Corridor, Raisan Village, Gandhinagar 382007, Gujarat, India., Khalid M; Graphene & Advanced 2D Materials Research Group, School of Engineering and Technology, Sunway University, No. 5 Jalan University, Bandar Sunway, Subang Jaya 47500, Malaysia., Mohd Sabri MF; Department of Mechanical Engineering, Faculty of Engineering, Universiti Malaya, Kuala Lumpur 50603, Malaysia., Mohd Salleh MF; Department of Electrical Engineering, Faculty of Engineering, Universiti Malaya, Kuala Lumpur 50603, Malaysia., Muhamad Sarih N; Department of Chemistry, Faculty of Science, Universiti Malaya, Kuala Lumpur 50603, Malaysia., Rahman S; Research Center for Nano-Materials and Energy Technology (RCNMET), School of Engineering and Technology, Sunway University, Bandar Sunway, Petaling Jaya 47500, Malaysia. |
| Abstrakt: |
The rheological behavior of two-dimensional (2D) MoS 2 -based ethylene glycol (EG) nanofluids (NFs) was investigated at low volume concentrations (0.005%, 0.0075%, and 0.01%) in a wide temperature range of 0-70 °C and at atmospheric pressure. A conventional two-step method was followed to prepare NFs at desired volume concentrations. Based on the control rotational (0.1-1000 s -1 shear rate) and oscillation (0.01-1000% strain) methods, the viscoelastic flow curves and thixotropic (3ITT (three interval thixotropic) and hysteresis loop) characteristics of NFs were examined. Shear flow behavior revealed a remarkable reduction (1.3~14.7%) in apparent dynamic viscosity, which showed concentration and temperature dependency. Such remarkable viscosity results were assigned to the change in activation energy of the ethylene glycol with the addition of MoS 2 . However, the nanofluids exhibited Newtonian behavior at all temperatures for concentrations below 0.01% between 10 and 1000 s -1 . On the other hand, strain sweep (@1Hz) indicated the viscoelastic nature of NFs with yielding, which varied with concentration and temperature. Besides, 3ITT and hysteresis loop analysis was evident of non-thixotropic behavior of NFs. Among all tested concentrations, 0.005% outperformed at almost all targeted temperatures. At the same time, ~11% improvement in thermal conductivity can be considered advantageous on top of the improved rheological properties. In addition, viscosity enhancement and reduction mechanisms were also discussed. |
