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

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.