碳纤维增强水泥基复合材料的制备及热电性能研究

将不同含量(0.5%,1.0%,1.5%(质量分数))的碳纤维掺入到硫铝酸盐水泥基体中,制备了碳纤维增强水泥基复合材料。通过SEM、阿基米德排水测试法、四探针法等手段,研究了碳纤维含量对增强水泥基复合材料断面结构、抗弯强度、孔隙率、电导率、热导率和塞贝克系数的影响,并模拟太阳辐射进行了能量收集实验。结果表明,碳纤维均匀地分布在水泥基体中形成网格结构,碳纤维与水泥基体有很强的结合力。当碳纤维含量由0.5%(质量分数)增加到1.5%(质量分数)时,水泥基复合材料的抗压强度由71.36 MPa增加到106.51 MPa,增长了49.26%;孔隙率由0.8%增加到2.0%,增长了150.0%;电导率由0.0214 S/m增加到0.2408 S/m,增长了1025%;热导率由0.261 W/(m·K)减小到0.210 W/(m·K),减少了19.54%;塞贝克系数迅速增大,最大为1.22×10^4μV/K。当碳纤维含量为1.5%(质量分数)时,厚度为20 mm的水泥基复合材料每1 m^2可输出5~6μW的功率;在400 min辐照下,试样表面温度迅速达到70℃左右,1 m^2水泥基复合材料面板上收集到的能量高达8.1×10^-6 J。由此可知,碳纤维含量的增加,极大地提高了碳纤维增强水泥基复合材料的热电性能。

Preparation and thermoelectric properties of carbonfiber reinforced cement-based composite

Carbon fiber reinforced cement-based composite was prepared by adding carbon fiber with different content(0.5 wt%,1.0 wt%,1.5 wt%)into sulphoaluminate cement matrix.The effects of carbon fiber content on the cross-section structure,flexural strength,porosity,conductivity,thermal conductivity and Seebeck coefficient of reinforced cement-based composite were studied by means of SEM,archimedes drainage test and four probe method,and the energy collection experiment was carried out by simulating solar radiation.The results showed that the carbon fibers were evenly distributed in the cement matrix to form a grid structure,and there was a strong binding force between the carbon fiber and the cement matrix.When the carbon fiber content increased from 0.5 wt%to 1.5 wt%,the compressive strength of cement-based composite increased from 71.36 MPa to 106.51 MPa,increased by 49.26%.The porosity increased from 0.8%to 2.0%,increased by 150.0%.The conductivity increased from 0.0214 S/m to 0.2408 S/m,increased by 1025%.The thermal conductivity decreased from 0.261 W/(m·K)to 0.210 W/(m·K),decreased by 19.54%.The Seebeck coefficient increases rapidly,and the maximum value was 1.22×10^4μV/K.When the carbon fiber content was 1.5 wt%,the cement-based composite with thickness of 20 mm could output 5-6μW power per 1 m^2.Under 400 min irradiation,the surface temperature of the sample rapidly reached about 70℃,and the energy collected on the 1 m^2 cement-based composite panel was as high as 8.1×10^-6 J.Therefore,the increase of carbon fiber content greatly improved the thermoelectric properties of carbon fiber reinforced cement-based composite.