Characterization and thermal properties of lauryl alcohol-capric acid binary mixture with hybrid-nanoparticles as phase change material for vaccine storage applications

The key challenge during vaccine cold chain logistics is maintaining a temperature range of 2-8 degrees C for the safe delivery of vaccines. In this study, a novel organic binary mixture of lauryl alcohol (LA) and capric acid (CA) with a weight fraction of 53:47 was developed as a phase change material (PCM) for passive cooling of vaccines during cold chain logistics. Considering the low thermal conductivity of organic PCM mixtures, carbon-metal -oxide based hybrid nanoparticles, namely GNP-Al2O3, GNP-CuO and GNP-TiO2 were chosen as thermal con-ductivity promoters. The hybrid nanoparticles were dispersed in a pure LA-CA binary mixture to develop hybrid nano-enhanced PCMs (HNePCMs). The chemical and thermal characterization of pure LA-CA and HNePCMs was examined. Scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) results reveal uniform dispersion and chemical compactness of hybrid nanoparticles in pure LA-CA. Fourier-transformed infrared (FTIR) results confirm that there is no chemical interaction between nanoparticles and LA-CA binary mixture. The pure LA-CA binary mixture possesses a melting temperature of 4.0 degrees C and melting latent heat of 170.7 J/g respec-tively. HNePCM of LA-CA/GNP-Al2O3 shows a maximum thermal conductivity enhancement of 55.7 %. How-ever, it shows a maximum deviation in melting temperature of 8 %. Besides, LA-CA/GNP-CuO shows a minimal deviation in melting temperature and latent heat and possesses improved thermal conductivity enhancement of 46 %. Thus, a developed LA-CA/GNP-CuO mixture with good chemical, thermal stability and long-term cycle durability can be employed as an ideal material for passive vaccine cooling during cold chain logistics.