Ultrasonication assisted co-dispersion of nanostructured magnesium-lined paraffin wax and magnesium oxide in a heat transfer fluid for energy related applications

• Published in: Journal of molecular liquids 2018-12, Vol.271, p.828-837
• Main Authors: Pavithra, S., Manikandan, S., Saranprabhu, M.K., Sivapalan, B., Rajan, K.S.
• Format: Article
• Language: English
• Subjects: Heat transfer coefficient augmentation; Improvement of thermo-physical properties; Magnesium-lined paraffin wax nanoparticles; Nanostructured magnesium oxide; Solar thermal
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2018.09.065

Magnesium-lined paraffin wax nanoparticles were prepared through probe ultrasonication, utilization of Tween 80 as surfactant and ionic interactions. These were co-dispersed with nanostructured magnesium oxide (0.6–2 vol%) in aqueous propylene glycol solution to obtain hybrid nanofluids. Magnesium-lined paraffin wax present in hybrid nanofluids underwent solid-liquid/liquid-solid transition between 45 °C and 62 °C during which thermal energy was absorbed/released, thereby increasing hybrid nanofluids' specific heat. The presence of magnesium oxide contributed to thermal conductivity enhancement of hybrid nanofluids, with a maximum of 20% for the one containing 2 vol% nanostructured magnesium oxide, attributable predominantly to the aggregation of primary nanoparticles as flower-like structure. Our data indicates augmentation of overall heat transfer coefficient with the utilization of hybrid nanofluid. •Water dispersible magnesium lined paraffin wax nanoparticles (PWM) prepared•Nanostructured magnesium oxide nanoparticles prepared•Hybrid nanofluid prepared by co-dispersion of PWM and magnesium oxide nanoparticles•Both thermal conductivity and specific heat enhancement for hybrid nanofluids•25 % higher overall heat transfer coefficient for renewable energy application