Preparation and Thermal Properties of KGM/CNC Carbon Aerogel Shaped Eutectic Salt Mirabilite Composite Phase Change Material
In order to solve the leakage problem of hydrated salt phase change material(PCM)and explore a lower-cost and environmentally friendly carbon aerogel to encapsulate hydrated salt phase change material,KGM/CNC carbon aerogel was successfully prepared by directional freezing-casting and high temperature carbonization using konjac glucomannan(KGM)and cellulose nanocrystal(CNC)as raw materials.Konjac glucomannan/cellulose nanocrystal phase change material(KGM/CNC PCM)was prepared by vacuum impregnation method using Na2SO4·10H2O-Na2HPO4·12H2O eutectic salt(EHS)with 0.2%(mass fraction)nano-carbon particles as phase change matrix.The structure composition of KGM/CNC carbon aerogel was analyzed by SEM,EDS,XRD,Raman,FTIR,XPS and BET.The thermal properties of KGM/CNC PCM were studied by DSC and TG.The results show that KGM/CNC carbon aerogel has good compatibility with EHS.KGM/CNC PCM could load 98.3%(mass fraction)EHS,and the melting enthalpy and crystallization enthalpy could reach 273.3 and 239.1 J·g-1,respectively.After 5 000 solid-liquid cycles,the melting enthalpy and crystallization enthalpy decrease by 1.4%and 2.8%,respectively.This paper solves the problem of poor cycle stability of hydrated salt phase change material,which is helpful to further promote the application of hydrated salt phase change energy storage material.