Polymer-dispersant-stabilized Ag nanofluids for heat transfer applications
- PDF / 1,401,165 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 53 Downloads / 246 Views
Polymer‑dispersant‑stabilized Ag nanofluids for heat transfer applications K. S. Pavithra1 · S. C. Gurumurthy2 · M. P. Yashoda1 · Tarun Mateti3 · Koduri Ramam4 · Roopa Nayak5 · M. S. Murari6 Received: 10 December 2019 / Accepted: 10 July 2020 © The Author(s) 2020
Abstract One-step wet chemical method has been employed for the synthesis of silver (Ag) nanofluids followed by the preparation of polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA) and PVP–PVA mixed-dispersant-stabilized nanofluids by varying the concentration ratio of dispersants for the viscosity and thermal conductivity analysis. The optical absorption studies indicate the presence of nanoparticles in the prepared fluids (or the formation of the silver nanoparticles). The shape and size of the nanoparticles are confirmed by the field emission scanning electron microscopy, and the particle size distribution and zeta potential analysis were carried out by using dynamic light scattering. It is observed that the thermal conductivity of Ag nanofluids increases with an increase in the dispersant concentration with respect to the temperature. The maximum thermal conductivity enhancement of Ag nanofluids was observed in the presence of an equimolar ratio of PVP–PVA (1:1:1) blends as stabilizers. Graphic abstract
Polymers blends
Ag nanofluids Ag nanofluids in polymer blends
Keywords Silver nanofluids · Dispersants · Viscosity · Thermal conductivity List of symbols k Thermal conductivity/W m−1 K kB Boltzmann constant Cp Specific heat capacity T Temperature/K U Uncertainty * M. P. Yashoda [email protected] Extended author information available on the last page of the article
𝜗 Dynamic viscosity/Pa s φ Nanoparticle volume fraction f Base fluid nf Nanofluid rc Apparent radius of cluster/Å knf Thermal conductivity of nanofluid kf Thermal conductivity of base fluid keff Effective thermal conductivity of nanofluids kp Thermal conductivity of particle
13
Vol.:(0123456789)
Introduction In recent advancements in technologies and industrial applications, there is a need for the development of highly efficient heat transfer and cooling devices. One of the decisive factors in industrial applications is to overcome the excess of heat production during the operation process and also to increase the reliability, thermal performance as well as working life of heat transfer devices [1]. Nanofluids are a colloidal suspension of ultrafine solid nanoparticles (NPs) like Cu, Zn, Ag, ZnO, CuO, T iO2, etc., into the conventional heat transfer fluids like ethylene glycol, water, and engine oils. It has been proved as one of the efficient ways to improve the thermal performance of the system by the addition of NPs into the conventional fluids, and hence, it is considered as one of the significant potential materials for heat transfer applications. Therefore, nanofluids have attracted special interest due to their potential benefits for numerous applications such as biomedical applications [2], fuel cells [3], heat transfer [4], photocatalytic [5], b
Data Loading...
