相变膨胀石墨/水泥复合材料的制备及其热电性能  

Preparation and thermoelectric properties of phase change expanded graphite/cement composite materials

作　　者：张思卿 魏剑[1] 王涛涛 惠嘉伟 郭宇鹏 王元 李雪婷 石宗墨 ZHANG Siqing;WEI Jian;WANG Taotao;HUI Jiawei;GUO Yupeng;WANG Yuan;LI Xueting;SHI Zongmo(College of Materials Science and Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)

机构地区：[1]西安建筑科技大学材料科学与工程学院,西安710055

出　　处：《复合材料学报》2024年第1期361-372,共12页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金面上项目(51578448,52272089);陕西省杰出青年科学基金(2021JC-43);陕西省自然科学基础研究计划-重大基础研究项目(2017ZDJC-18);陕西省教育厅协同创新项目(20JY042)。

摘　　要：热电水泥基复合材料可以将建筑物环境中的热能转化成电能,作为一种新型的能源转换途径,近年来受到了广泛关注和研究。热电水泥基复合材料在应用过程中存在最佳工作温度与环境温度不匹配的问题及热电转换效率过低,制约了热电水泥的应用。本文将熔融共混制备的膨胀石墨(EG)/石蜡(PW)相变复合材料掺入水泥基材料中,制备相变膨胀石墨/水泥复合材料。研究相变复合材料掺入量对水泥基材料热电性能的影响。相变复合材料含量的增加调节了水泥基复合材料最佳热电性能的温度区间。测试结果表明热电性能最大值对应的温度点由55℃调节至60℃和65℃,其对应的Seebeck系数分别为−24.65、−30.97和−30.90μV/K,功率因数分别为1.39、1.57和1.67μW·m^(−1)·K^(−2);热电优值(ZT)分别为5.53×10^(−5)、6.50×10^(−5)和7.07×10^(−5)。相变复合材料在相变过程中吸收热量,降低了水泥基材料的升温速率,削弱了因温度升高导致载流子浓度增加引起Seebeck系数的下降,调节了水泥基材料功率因数峰值对应的温度区间,调控了热电水泥基复合材料的使用温度范围。本文为改善热电水泥基复合材料性能提供了新的途径和方法。Thermoelectric cement-based composite materials can convert thermal energy in building environments into electrical energy,and as a new energy conversion approach,have received widespread attention and research in recent years.There is a problem of mismatch between the optimal working temperature and environmental temperature in the application of thermoelectric cement-based composite materials,and the low thermoelectric conversion efficiency restricts the application of thermoelectric cement.This study incorporated expanded graphite(EG)/paraffin wax(PW)phase change composite materials prepared by melt blending into cement-based materials to prepare phase change expanded graphite/cement composite materials.The effect of the addition amount of phase change composites on the thermoelectric properties of cement-based materials was studied.The increase in the content of phase change composites regulates the temperature range for the optimal thermoelectric performance of cement-based composite materials.The test results show that the temperature point corresponding to the maximum thermoelectric performance is adjusted from 55℃to 60℃and 65℃.The corresponding Seebeck coefficient is−24.65,−30.97 and−30.90μV/K.The power factor is 1.39,1.57 and 1.67μW·m^(−1)·K^(−2).Thermoelectric merit(ZT)value is 5.53×10^(−5),6.50×10^(−5)and 7.07×10^(−5).Phase change composites absorb heat during the phase change process,reducing the heating rate of cement-based materials,weakening the decrease in Seebeck coefficient caused by an increase in carrier concentration due to temperature rise,adjusting the temperature range corresponding to the peak power factor of cement-based materials,and regulating the temperature range of use of thermoelectric cement-based composite materials.This study provides a new approach and method for improving the performance of thermoelectric cement-based composite materials.

关 键 词：石蜡 膨胀石墨 相变材料 水泥基材料 热电性能 

分 类 号：TB332[一般工业技术—材料科学与工程]