Viscosity and thermal conductivity of ZnO–water‑based nanofuids stabilized by grafted SMA‑g‑MPEG comb‑shaped copolymer for heat transfer applications

Pavitra, K S and Yashoda, M P and Prasannakumar, S and Mutalik, Srinivas (2020) Viscosity and thermal conductivity of ZnO–water‑based nanofuids stabilized by grafted SMA‑g‑MPEG comb‑shaped copolymer for heat transfer applications. Iranian Polymer Journal, 29. pp. 185-196. ISSN 1026-1265

[img] PDF
8769.pdf - Published Version
Restricted to Registered users only

Download (1MB) | Request a copy

Abstract

In this work, the efect of poly(styrene-co-maleic anhydride)-grafted methoxy (polyethylene glycol) (SMA-g-MPEG) copolymer as dispersants on the viscosity and thermal conductivity of zinc oxide (ZnO)–water-based nanofuids was studied. Various molecular weight MPEGs were grafted to SMA copolymer by esterifcation reaction, and ZnO nanoparticles (NPs) were prepared by microwave irradiation method. Prepared ZnO NPs and copolymers were characterized by UV, FESEM, TEM, XRD, FTIR, NMR and TGA techniques. The grafted copolymer was used to enhance the dispersibility of ZnO–water-based nanofuids. The efect of SMA-g-MPEG comb-shaped copolymer on the viscosity and thermal conductivity of the suspensions was investigated at diferent concentrations (0.1, 0.3 and 0.5 wt%) and solid volume fractions of ZnO NPs (φ = 0.5–3.0%). The suspension with SMA-g-MPEG 2000 dispersant showed improved stabilization at higher particle concentration. The variation of viscosity with shear rate showed the nanofuids behaved as a non-Newtonian fuid at the lower shear rate and Newtonian behaviour with the increase in shear rate. However, thermal conductivities of the ZnO–water-based nanofuids increased with increasing of the particle volume concentration and decreased with increase in the chain length of the grafted molecules. The average chain length of the grafted molecule exhibited enhanced thermal conductivity as compared with that of the base fuids. Finally, experimental values of the thermal conductivity and viscosity were compared with the estimations done by several simple theoretical models.

Item Type: Article
Uncontrolled Keywords: ZnO nanofuids · Microwave irradiation method · Dispersants · Viscosity · Stability · Thermal conductivity
Subjects: Engineering > MIT Manipal > Chemistry
Pharmacy > MCOPS Manipal > Pharmaceutics
Depositing User: MIT Library
Date Deposited: 27 Jun 2020 10:27
Last Modified: 27 Jun 2020 10:27
URI: http://eprints.manipal.edu/id/eprint/155361

Actions (login required)

View Item View Item