title: Carbon Hollow Microspheres with a Designable Mesoporous Shell for High-Performance Electromagnetic Wave Absorption.
abstract: In this work, mesoporous carbon hollow microspheres (PCHMs) with designable mesoporous shell and interior void are constructed by a facile in situ stöber templating approach and a pyrolysis-etching process. The PCHMs are characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectra, Raman spectroscopy, and nitrogen adsorption and desorption system. A uniform mesoporous shell (pore size 4.7 nm) with a thickness of 55 nm and a cavity size of 345 nm is realized. The composite of paraffin mixed with 20 wt % PCHMs exhibits a minimum reflection coefficient (RCmin) of -84 dB at 8.2 GHz with a sample thickness of 3.9 mm and an effective absorption bandwidth (EAB) of 4.8 GHz below -10 dB (>90% electromagnetic wave is attenuated). Moreover, the composite of phenolic resin mixed with 20 wt % PCHMs exhibits an ultrawide EAB of 8 GHz below -10 dB with a thinner thickness of 2.15 mm. Such excellent electromagnetic wave absorption properties are ascribed to the large carbon-air interface in the mesoporous shell and interior void, which is favorable for the matching of characteristic impedance as compared with carbon hollow microspheres and carbon solid microspheres. Considering the excellent performance of PCHMs, we believe the as-fabricated PCHMs can be promising candidates as highly effective microwave absorbers, and the design philosophy can be extended to other spherical absorbers.
authors.affiliation: Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University , Xi'an 710072, China.
authors.forename: Hailong
authors.identifier: http://orcid.org/0000-0003-1223-1693
authors.initials: H
authors.lastname: Xu
authors.affiliation: Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University , Xi'an 710072, China.
authors.forename: Xiaowei
authors.identifier: http://orcid.org/0000-0001-8756-8624
authors.initials: X
authors.lastname: Yin
authors.affiliation: Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University , Xi'an 710072, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University , Xi'an 710072, China.
authors.forename: Meikang
authors.initials: M
authors.lastname: Han
authors.affiliation: Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University , Xi'an 710072, China.
authors.forename: Zexin
authors.initials: Z
authors.lastname: Hou
authors.affiliation: Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University , Xi'an 710072, China.
authors.forename: Xinliang
authors.initials: X
authors.lastname: Li
authors.affiliation: Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University , Xi'an 710072, China.
authors.forename: Litong
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Science and Technology on Thermostructural Composite Materials Laboratory, Northwestern Polytechnical University , Xi'an 710072, China.
authors.forename: Laifei
authors.initials: L
authors.lastname: Cheng
keywords: carbon hollow microspheres; carbon-air interface; dielectric properties; electromagnetic wave absorption; mesoporous shell