FeBP@SiO_(2)核壳结构纳米复合材料的可控制备及其吸波性能

Controllable Preparation and Microwave Absorbing Properties of FeBP@SiO_(2) Core-Shell Nanocomposites

提出一种简便易行的方法制备核壳型FeBP@SiO_(2)纳米粒子,该方法利用化学还原和溶胶凝胶相结合,实现复合粒子的核壳结构可控。通过改变SiO_(2)壳厚度,研究了壳层厚度对吸波性能的影响,并对微波吸收机制进行分析和解释。结果表明,随着SiO_(2)壳层厚度的增加,粒子微波吸收能力先增大后减小。当SiO_(2)壳层厚度为38 nm时,FeBP@SiO_(2)样品具有最强的微波吸收性能,在吸收涂层厚度为2.19 mm下反射损耗获得较好的吸收性能(-52.66 dB),这种增强的微波吸收性能主要来自新增磁-介电界面,从而提高了材料的阻抗匹配以及介电损耗的能力,通过设计复合粒子的核壳结构,可以实现复合吸波剂的性能调控,因此本研究为设计下一代新型复合微波吸收材料提供了重要参考。

Core-shell FeBP@SiO_(2) nanoparticles were prepared by a facile method.This method combines chemical reduction and sol-gel to realize the controllable core-shell structure of composite particles.By changing the thickness of SiO_(2) shell,the effect of shell thickness on microwave absorption performance was studied,and the microwave absorption mechanism was analyzed.Results show that with increasing the SiO_(2) shell thickness,the microwave absorption capacity of the particles is increased firstly and then decreased.When the thickness of the SiO_(2) shell is 38 nm,the FeBP@SiO_(2) sample has the strongest microwave absorption performance,and the sample with the absorption coating thickness of 2.19 mm obtains better absorption performance(-52.66 dB).This enhanced microwave absorption performance is mainly attributed to the new magnetic-dielectric interface,which improves the impedance matching and dielectric loss of the material.By designing the core-shell structure of the composite particles,the performance regulation of the composite absorber can be achieved.Therefore,this work provides an important reference for the design of the next generation composite microwave absorbing materials.