羟基磷灰石气凝胶复合相变材料的制备及其性能

以相变材料为核心的潜热储存技术，对加快新能源开发和提高能源利用率起着关键性作用。以油酸钙为前驱体，通过水热法合成了具有自支撑网络结构的羟基磷灰石（HAP）气凝胶，并采用浸渍法制备出自支撑羟基磷灰石复合相变材料。通过扫描电镜、傅里叶红外光谱、X射线衍射、热重法、差示扫描量热法等手段对所制备复合相变材料的形貌、稳定性、热性能等进行了表征及测试。实验结果表明，负载石蜡或十八醇的羟基磷灰石气凝胶复合相变材料均具有良好的热性能，质量分数60%石蜡@HAP气凝胶复合相变材料的熔融焓和凝固焓测量值分别为85.10和85.30 J·g?1，结晶度为81.50%；质量分数60%十八醇@HAP气凝胶复合相变材料的熔融焓和凝固焓测量值为113.78和112.25 J·g?1，结晶度为86.20%，且具有很好的热稳定性和化学稳定性。此外，羟基磷灰石气凝胶载体材料阻燃性好，无腐蚀且安全环保，有效拓展了相变材料在智能保温纺织物和建筑材料等领域的实际应用。 

Preparation and properties of hydroxyapatite aerogel composite phase change materials

To address energy shortage and environmental pollution, scientists are working to develop methods for the production, conversion, and storage of new energy sources. The development of thermal energy storage (TES) is considered to be one of the most effective energy conservation and environmental protection strategies for utilizing various renewable energy sources. Energy storage technology can solve the contradiction between energy supply and demand in time and space and also improve energy efficiency. Currently, TES includes mainly sensible heat storage, latent heat storage, and thermochemical energy storage. The latent heat TES based on phase change materials (PCMs) is an efficient technology that is being actively pursued owing to high storage density in a small temperature region, which is essential for accelerating new energy development and improving energy efficiency. In this paper, hydroxyapatite aerogels with self-supporting network structure were prepared via a hydrothermal method using calcium oleate as a precursor. Self-supporting hydroxyapatite-based composite phase change materials were synthesized using the impregnation method. The morphology and thermal properties of the prepared composite phase change materials were characterized and tested by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetry, and differential scanning calorimetry. The experimental results show that the composite phase change materials of hydroxyapatite aerogels loaded with octadecanol or paraffin have good thermal properties. The measured values of melting enthalpy and solidified enthalpy of the 60% paraffin@HAP composite phase change materials are 85.10 and 85.30 J·g?1, respectively, and its crystallinity is 81.50%. The measured values of melting enthalpy and solidified enthalpy of the 60% octadecanol@HAP composite phase change material are 113.78 and 112.25 J·g?1, respectively, and its crystallinity is 86.20%. In addition, the composite has good thermal and chemical stability. Furthermore, the hydroxyapatite substrate has the advantages of good flame retardancy, corrosion-free characteristics, safety, and environmental protection, which effectively expands the practical application of phase change materials in the field of intelligent thermal insulation textiles and building materials.