改性氧化铜/正十八烷复合相变材料制备及性能表征研究OA北大核心CSTPCD

To enhance the stability and thermophysical properties of composite phase change materials(CPCM),sodium oleate(SOA)was employed to modify CuO nanoparticles,integrating them with n-octadecane to formulate PCMs at varying modified nanoparticle(M-CuO)concentrations.The experimental outcomes indicated a significant increase in the thermal conductivity of CPCM containing 3.0%M-CuO—up to 282.9%compared to pure n-octadecane.Additionally,the melting enthalpy decreased by as much as 6.3%with an M-CuO content of 2.0%.To further enhance the dispersion stability of the nanoparticles,sodium oleate was incorporated as a surfactant,resulting in a thermal conductivity increment of 10.4%for the CPCM compared to those without the surfactant.Molecular dynamics modeling of M-CuO/n-octadecane CPCM revealed that the thermal conductivity was enhanced by 8.6%,10.4%,and 11.2%at nanoparticle distances of 20 Å,30 Å,and 40 Å,respectively.Moreover,the interaction energies between M-CuO nanoparticles were reduced by 22.9,16.3,and 20.0 kcal/mol,respectively,indicating a reduction in interaction energy and an enhancement in their stability.This study provides critical theoretical insights into the thermophysical property enhancement and optimization of CPCM,uncovering the fundamental microscopic mechanisms involved.