水热法制备防辐射外墙用SiC/r-GO复合材料结构及电磁特性

Structure and electromagnetic characteristics of SiC/r-go composites for radiation-proof exterior walls prepared by hydrothermal method

选择水热工艺制备了以还原石墨烯对包裹碳化硅棒的三维网状结构(SiC/r-GO),采用这种特定结构可以获得更优的微波吸收效果。实验结果表明:受到羟基、羧基等含氧基团的作用后,石墨片层形成了更大的间距。SiC/r-GO表面形成了许多褶皱形态的r-GO,表现出三维交织的特征。SiC棒形成了均匀结构,相互间呈现交织分布,在表面形成包裹石墨层。当温度升高到350℃以上时,曲线快速降低,此时复合材料内的r-GO发生了分解。当填充比例增大后,形成了更大复介电常数实部,获得更强的极化作用。2~18GHz频率区间的复介电常数实部与虚部都随频率的提高而降低。采用水热工艺处理会导致r-GO纳米薄片表面形成残余官能团并产生许多缺陷,受到交变电磁场影响后出现空间电荷极化,从而导致介电损耗。

A three-dimensional network component(SiC/r-go) coated with reduced graphene was prepared by hydrothermal process. The better microwave absorption effect could be obtained by using this specific structure.The experimental results showed that the graphite layer formed a larger gap when the hydroxyl group, carboxyl group and other oxygen-containing groups acted on it.The surface of SiC/r-go formed many folds of r-go, which were characterized by three-dimensional interlacing. The SiC rods form a uniform structure and interweave with each other, forming a layer of coated graphite on the surface. When the temperature rose to 350 ℃, a rapidly decreasing curve was formed, and the r-go in the composite material had decomposed. When the filling proportion increases, a larger part of the complex dielectric constant was formed, and stronger polarization was obtained. The real and imaginary parts of the complex dielectric constant in the frequency range of 2-18 GHz decreased with the increase of the frequency. The application of hydrothermal technology led to the formation of residual functional groups on the surface of r-go nanosheets and many defects. The polarization of space charge occured under the influence of alternating electromagnetic fields, resulting in dielectric loss.