Ruishuo Guo,Huijia Wang,Qingwen Wen,Xin Xu,Yanlan Zhou,Xiaoqiang Shao,Ni Li
Phase change capsules effectively address the limitations of leakage and poor stability of phase change materials (PCMs). In this study, SiO 2 @n-Octadecane phase change nanocapsules (PCNCs) with controllable size and structure are prepared by controlling material ratios. When Water-to-EtOH ratio is 2:1 and C 18 -to-TEOS ratio is 3:3 in the reaction system, prepared PCNCs show excellent phase change enthalpy of 152.9 J/g and high encapsulation ratio of 73.77 %, with desirable thermal stability and reliability. After the irradiation of simulating sunlight for 1500 s, the PCNCs achieved a temperature buffer of 6 °C compared with blank cotton fabric, and the cotton fabric with the PU coating containing the PCNCs presents up to 13.2 °C temperature reduction compared with original cotton fabric. The prepared SiO 2 @n-Octadecane PCNCs present excellent heat storage and thermal management performance and effective strategy to develop long-term thermal comfort smart textiles.
In this manuscript, CuS-ZnS/SiO 2 @n-octadecane nanocapsules were prepared by a simple one-step Cu 2+ and Zn 2+ co-deposition method. The results of XRD, SEM, TEM, FTIR and XPS show that nanocapsules composed of CuS-ZnS/SiO 2 shell and n-octadecane core material were successfully prepared, and the particles deposited was proved to be composite structure of CuS-ZnS. The solution concentration, reaction temperature and pH value have significant effects on the morphology of the nanocapsules prepared. The appropriate conditions are 0.02 mol/L CuSO 4 , 0.02 mol/L Zn(CH 3 COO) 2 , 60 °C, and no additional pH adjustment. Under the optimum conditions, the melting enthalpy reached 45.11 J/g, and after 100 times of cold and hot cycles, the melting enthalpy of the sample only decreased by 3.2%, showing good thermal stability. The CuS-ZnS composite structure makes CuS-ZnS/SiO 2 nanocapsules exhibit a wider spectrum absorption performance. The absorption effect of CuS-ZnS/SiO 2 nanocapsules to ultraviolet light is significant, compared to the slight reducing of the visible light, while the absorption of near-infrared light is strong. The photothermal conversion efficiency of the samples is significantly improved from 9.7% to 86.6%. Hence, the prepared nanocapsules achieve full spectral absorption, which has a broad application prospect in solar thermal utilization.
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