石墨烯增强水泥基复合材料的制备及热电性能研究

Preparation and thermoelectric properties ofgraphene-reinforced cement-based composites

采用球磨法,以多层石墨烯纳米片(GNP)为增强相,制备了不同GNP含量的石墨烯纳米片水泥基复合材料(GNP/CBC)。采用场发射扫描电子显微镜和X射线衍射仪对复合材料的微观结构进行表征,运用四探针电导率仪和差示扫描量热仪、傅里叶红外光谱仪、霍尔效应测试仪等对复合材料的热电性能进行研究。结果表明,石墨烯增强的水泥基复合材料的电导率随GNP含量的增加而增加,在70℃、GNP含量为20%(质量分数)时,复合材料的电导率最高为16.2 S/cm,功率因数最大值为1.6μW/(m·K^2);复合材料的塞贝克系数随温度的升高而增加,在70℃、GNP含量为15%(质量分数)时,复合材料的塞贝克系数最大为34μV/K,霍尔系数最大为+0.842 cm 2/C,同时品质因数最高可达1.44×10-3。GNP/CBC可潜在地应用于建筑物的室内气候改善和城市热岛(UHI)效应缓解。

The cement-based composite(GNP/CBC)with different GNP content was prepared by ball milling with multilayer graphenenanoflakes(GNP)as reinforcem ent.The microstructure of the composite was characterized by field emission scanning electron microscopy and X-ray diffraction.The thermoelectric properties of the composite were studied by four probe conductivity meter,differential scanning calorimeter,Fourier infrared spectrometer and Hall effect tester.The results showed that the conductivity of the composites increased with the increase of GNP content.When the GNP content was 20wt%at 70°C,the highest conductivity was 16.2 S/cm,and the maximum power factor was 1.6μW/(m·K^2).The Seebeck coefficient of the composite increased with the increase of temperature.When the GNP content was 15wt%,the maximum Seebeck coefficient of the composite was 34μV/K,the maximum Hall coefficient was+0.842 cm 2/C,and the maximum quality factor was 1.44×10-3.The cement-based composite(GNP/CBC)could be potentially applied to indoor climate improvement of buildings and mitigation of urban heat island(UHI)effect.