Vol.:(0123456789) 1 3 Clean Technologies and Environmental Policy https://doi.org/10.1007/s10098-020-01854-7 ORIGINAL PAPER Nano‑enhanced PCMs for low‑temperature thermal energy storage systems and passive conditioning applications Rajat Saxena 1  · Charu Dwivedi 2  · Viresh Dutta 2  · S. C. Kaushik 2  · Dibakar Rakshit 2 Received: 31 October 2019 / Accepted: 25 April 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Phase change material (PCM)-based thermal energy storage (TES) systems are preferred due to high energy density; how- ever, they possess an inherent problem of low dispatchability. This is due to the low thermal conductivity of the constituent PCMs. For ensuring high energy density and high rate of dispatchability of the TES systems, it is necessary to fnd methods to enhance the thermal conductivity of these PCMs. The present study chooses low-temperature melting PCM (n-nonade- cane) which is suitable for thermal regulation of various devices, systems and buildings. For enhancement of PCM, TiO 2 nanoparticles are prepared using continuous spray pyrolysis method and dispersed within the PCM matrix using advanced wet impregnation technique, to form nano-enhanced PCMs (NEPCMs). The thermal properties of these NEPCMs have been adjudged, in this study. The advanced wet impregnation technique ensures uniform mixing of nanoparticles, and no visual separation or settling issues are encountered up to 2% by weight concentration. An increase in thermal conductivity up to 37% is observed. It is also observed that beyond 2% concentration, partial settling of nanoparticles is observed over a 1-week duration. Graphic abstract Keywords Thermo-physical properties · Continuous spay pyrolysis (CoSP) · Diferential scanning calorimeter (DSC) · Thermal conductivity meter · Nano-enhanced phase change materials (NEPCMs) * Dibakar Rakshit dibakar@iitd.ac.in Extended author information available on the last page of the article