Journal Article

Microwave absorption properties of gamma-Fe.sub.2O.sub.3/.sub.x-SO.sub.3H/polypyrrole core/shell/shell microspheres

Zhang, Zhiming, Jiang, Xiaohui, Yu, Liangmin, Ji, Shengning, Li, Cuiping, Zhang, Yajie

2018

Overview

Highly regulated [gamma]-Fe.sub.2O.sub.3/(SiO.sub.2).sub.x-SO.sub.3H/polypyrrole (FS.sub.xHP) composite core/shell/shell microspheres are successfully prepared through a SiO.sub.2 sol-gel process and an in situ polymerization of pyrrole monomers. [gamma]-Fe.sub.2O.sub.3 functions as the \"core,\" whereas SiO.sub.2 and polypyrrole (PPy) act as the \"shells\" of the composite. In contrast to many previously reported FS.sub.2H-P and PPy-based composites, the FS.sub.xHP composites display substantially improved microwave absorption properties, which can reach nearly - 43.1 dB (15.1 GHz) with a broader effective absorption bandwidth (RL < - 10 dB) of 6.1 GHz. The excellent microwave-absorbing properties of the FS.sub.xHP composites are closely associated with the layer of SiO.sub.2 shells and can be attributed to the proper impedance matching and synergistic interaction of the special core/shell/shell structures, dielectric loss (SiO.sub.2 and PPy layers) and magnetic loss ([gamma]-Fe.sub.2O.sub.3). These results show that the core/shell/shell structure may be an efficient and promising way to improve microwave absorption properties.

• Publisher: Springer
• Subject: Polymerization