利用粉煤灰制备Ni负载的微波吸收材料

Ni-Loaded Composites as Microwave Absorption Materials byRecycling of Coal Fly Ash

粉煤灰(CFA)的回收利用对缓解日益严重的环境污染具有重要意义。本文以CFA为原料,利用简单的“一锅法”设计合成负载Ni的复合微波吸收材料(Ni/CFA-x),以实现低成本吸收材料的制备和CFA资源回收利用。研究表明,随硝酸镍前驱体溶液浓度的增加,材料的吸波效果先增强后减弱。负载适量的金属Ni颗粒,使得材料介电和磁性组分之间的有效复合表现出显著增强的微波吸收性能。当硝酸镍前驱体溶液浓度为1.0 mol/L时,材料的吸波效果最佳,在2.0 mm涂层厚度下,材料最小反射损耗达到-47.9 dB,对应的有效吸收带宽达到4.2 GHz。材料优异的吸波性能主要源于金属Ni颗粒与一定石墨化程度碳引起的导电损耗及其与CFA基体各组元间的界面极化损耗。

The recycle of coal fly ash(CFA)is of momentous value to relieve the growing levels of the serious environment pollution.To achieve the preparation of low-cost microwave absorption materials and the recycling of CFA resources,the Ni-loaded CFA composites(Ni/CFA-x)used as microwave absorption materials were synthesized by a facile“one-pot”method using solid waste CFA as the raw material.The results show that with the increase of the concentration of nickel nitrate precursor solution,the microwave absorbing properties improve first and then decrease.The effective combination between the dielectric and magnetic components of the material exhibits significantly enhanced microwave absorption performance,through loading an appropriate amount of metal Ni particles.When the concentration of nickel nitrate precursor solution is 1.0 mol/L,the microwave absorption performance of Ni/CFA-1.0 is best.At a coating thickness of 2.0 mm,the minimum reflection loss reaches-47.9 dB,and the corresponding effective absorption bandwidth is 4.2 GHz.The excellent microwave absorption performance can be attributed to the conduction loss caused by the metal Ni particles and a certain degree of graphitization of carbon,and the interface polarization loss among the Ni particles,carbon and CFA matrix.