Silica encapsulation of n-octadecane via sol-gel process: A novel microencapsulated phase-change material with enhanced thermal conductivity and performance
Silica encapsulation of n-octadecane via sol-gel process: A novel microencapsulated phase-change material with enhanced thermal conductivity and performance
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DOI：
10.1016/j.jcis.2009.11.036
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发表时间：
2010-03-01
影响因子：
9.9
通讯作者：
Wu, Dezhen
中科院分区：
文献类型：
--
作者：
Zhang, Huanzhi;Wang, Xiaodong;Wu, Dezhen
设计了一种基于正十八烷核和无机二氧化硅壳层的新型微胶囊相变材料(PCM)，以提高导热性能和相变性能。以正硅酸乙酯为无机源，采用溶胶-凝胶法合成了二氧化硅微胶囊。傅里叶变换红外光谱证实了硅壳材料已成功地制备到正十八烷核的表面。扫描电子显微镜图像显示，二氧化硅微胶囊呈球形，具有明确的核壳结构。此外，在pH值为2.45的条件下合成的二氧化硅微胶囊表面光滑致密。广角X射线散射图表明，二氧化硅微胶囊中的正十八烷仍保持着良好的结晶度。热重分析表明，这些二氧化硅微胶囊分两个不同的步骤降解，具有良好的热稳定性。在溶胶-凝胶过程中，通过控制芯材的用量和反应溶液的酸度，二氧化硅微胶囊化正十八烷可以获得良好的相变性能、高的包封率和良好的抗渗透性能。由于高导热硅胶外壳的存在，微胶囊化的正十八烷的导热系数也显著提高。(C)2009 Elsevier Inc.保留所有权利。
A novel microencapsulated phase-change material (PCM) based on an n-octadecane core and an inorganic silica shell was designed to enhance thermal conductivity and phase-change performance. These silica microcapsules were synthesized by using TEOS as an inorganic Source through a sol-gel process. Fourier transform infrared spectra confirm that the silica shell material Was Successfully fabricated onto the surface of the n-octadecane core. Scanning electronic microscopy images Suggest that the silica microcapsules exhibit a spherical morphology with a well-defined core-shell microstructure. Furthermore, the silica microcapsules synthesized at pH 2.45 display a smooth and compact surface. These microcapsules also present a large particle size range of 7-16 mu m. Wide-angle X-ray scattering patterns indicate that the n-octadecane inside the silica microcapsules still retains a good Crystallinity. Thermogravimetric analysis shows that these silica microcapsules are degraded in two distinct steps, and have good thermal stability. The silica-microencapsulated n-octadecane can achieve good phase-change performance, high encapsulation efficiency, and good antiosmosis property by controlling the loading of core material and acidity of the reaction solution during the sol-gel process. The thermal conductivity of the microencapsulated n-octadecane is also significantly enhanced due to the presence of the high thermal Conductive silica shell. (c) 2009 Elsevier Inc. All rights reserved.