Development of low-temperature eutectic phase change material with expanded graphite for vaccine cold chain logistics

Abstract

This research aims to explore a novel PCM that can satisfy the needs of vaccine cold chain logistics temperature zone (2–8 °C), with decyl alcohol (DA) and lauric acid (LA) chose to be eutectic. Considering the thermal conductivity and leakage of materials, DA-LA/EG composite phase change material (CPCM) with a mass ratio of 12:1 is prepared by the vacuum adsorption method. The thermal properties of DA-LA/EG CPCM are analyzed by DSC, cooling curve, Hot Disk, SEM etc. From the DSC graphs of DA-LA eutectic phase change material (EPCM), it is found that there is difference between the melting temperature and solidification temperature, which is defined as phase change hysteresis. The results indicate that the phase transition temperature of DA-LA/EG CPCM is 2.08 °C, with high latent heat and thermal conductivity of 188.71 J g−1 and 1.7527 W m−1 K−1, respectively. Due to the unique porous structure of EG, the thermal conductivity is 13.75 times higher than that without EG, which leads to the phase transition time shortened by 79.47%. Furthermore, DA-LA/EG CPCM shows excellent cyclic stability and chemical stability after 500 high-low temperature alternating tests. From TGA, the decomposition temperature of DA-LA/EG CPCM is 186.55 °C, higher than the working temperature range. The applicability is demonstrated by using the CPCM into an incubator. Overall, DA-LA/EG CPCM has good application prospects in vaccine cold chain logistics.