Design,Preparation And Performance Research Of Multifunction Composite Phase Change Materials

To address the susceptible leakage of stearyl alcohol（SA）in the melting stage,low thermal conductivity,single function and so on,three kinds of multifunctional phase change heat storage materials（PCMs）have been synthesized by melt blending and hot-pressing techniques dispersing SA,thermal conductivity and functional materials uniformly into the cross-linking polymerization network of olefin block copolymer（OBC）.The details are as follow:（1）The phase change heat storage materials（LAL/SA/OBC）with photoluminescence function have been fabricated by using OBC as the supporting materials,SA as the PCMs and long afterglow luminescent material(LAL,Sr Al₂O₄:Eu²⁺,Dy³⁺)as the luminescent material.Thermal analysis shows that the latent enthalpy of the LAL/SA/OBC is 116.5～152.6 J·g^-1,and its thermal conductivity is increased to0.4538 W·m^-1·K^-1（78.7%higher than that of SA）.The fluorescence analysis indicates that the LAL/SA/OBC can emit green light in the dark after it is excited by light at 300～450 nm.The simulation experiment of thermal regulation proves that the LAL/SA/OBC can be used as a building covering to regulate the temperature of the roof and interior of the building.（2）The phase change heat storage materials（TC-PCMs/OBC）with reversible thermochromism and shape memory function have been prepared by blending and hot-pressing crystal violet lactone（CVL）,bisphenol A（BPA）,SA and OBC.Thermal analysis demonstrates that 60TC-PCMs/OBC has a better thermal storage performance(126.0 J·g^-1)as the SA is 60 wt%.Due to its good reversible thermochromic ability,it can reflect the progress of the material phase transition and the change of ambient temperature through color change.TC-PCMs/OBC exhibit thermally induced flexible and thermally driven shape memory property near its melting point under the interaction between the solid-liquid phase transition of SA and the soft-hard chain segments of OBC.（3）In order to solve the problem of poor thermal conductivity of TC-PCMs/OBC,the multifunctional phase change thin films（TC-PCMs/n BN/OBC）have been prepared by adding h-BN as a thermally conductive filler in TC-PCMs/OBC.SEM analysis displays that thermal conductivity of TC-PCMs/10BN/OBC increases from 0.2414W·m^-1·K^-1 to 0.4233 W·m^-1·K^-1 by using hot-pressing making h-BN to arrange horizontally in the TC-PCMs/n BN/OBC and construct an efficient heat transfer path.And TC-PCMs/10BN/OBC has excellent flexibility and tailorability.The research results also demonstrate that the melt enthalpy of TC-PCMs/10BN/OBC is 121.6 J·g^-1and its photothermal conversion efficiency is 89.8%.The two-dimensional code is customized by TC-PCMs/n BN/OBC,and the results show that the information hiding and displaying can be realized by temperature control.The electrothermal conversion efficiency of the flexible device（TC-PCM/10BN/OBC）is 86.5%by layer-by-layer assembly of TC-PCMs/10BN/OBC and conductive cloth.