低共熔溶剂透明相变木材的构建OA

To address the problems of easy leakage and inappropriate phase-change temperatures deviating from the human com-fort zone in traditional phase-change materials(PCM),and to support building energy conservation under the"dual car-bon"goal,transparent phase-change wood(TW-DES)with both light transmittance and phase-change energy storage functions was prepared using balsa wood(Ochroma pyramidale)as the substrate.The results showed that a ternary deep eutectic solvent(DES)was first synthesized with a mass fraction ratio of capric acid:palmitic acid:n-octadecane=16.9∶3.1∶80.0.Its melting and crystallization enthalpies reached 209.90 and 215.40 J·g-1,and the melting and crystalliza-tion phase-change temperatures were 25.1-27.0℃and 19.4-20.4℃,respectively,matching the human comfort range of 22.0-27.0℃.Subsequently,delignified wood(DW)was obtained by delignification of balsa wood using an acetic acid-sodium chlorite system.Its specific surface area increased from 1.035 m2·g-1 for natural wood to 2.563 m2·g-1,with a well-preserved porous framework,providing an excellent carrier for impregnation.Finally,epoxy resin(EP)and the ternary DES were compounded,impregnated into the delignified wood under vacuum,and cured to obtain a series of TW-DES samples.Characterization demonstrated that TW-DES-50(with 50%mass fraction of ternary DES)exhibited the best comprehensive performance,with a light transmittance of 79.67%at 400-800 nm and thermo-responsive optical reversibility.Differential scanning calorimetry(DSC)confirmed melting and crystallization enthalpies of 95.98 and 100.50 J·g-1,without leakage of the ternary DES.Infrared thermal imaging showed that its temperature drop was only 11.4℃within 40 s at 0℃,superior to natural wood(32.8℃)and transparent wood(29.4℃).Fourier-transform infrared spec-troscopy(FTIR)verified that the epoxy resin-ternary DES(EP-DES)composite was only physically combined with delig-nified wood,showing good compatibility.