An atomic layer deposition （ALD） method has been employed to synthesize Fe3O4/graphene and Ni/graphene composites. The structure and microwave absorbing properties of the as-prepared composites are investigated. The...An atomic layer deposition （ALD） method has been employed to synthesize Fe3O4/graphene and Ni/graphene composites. The structure and microwave absorbing properties of the as-prepared composites are investigated. The surfaces of graphene are densely covered by Fe3O4 or Ni nanoparticles with a narrow size distribution, and the magnetic nanoparticles are well distributed on each graphene sheet without significant conglomeration or large vacancies. The coated graphene materials exhibit remarkably improved electromagnetic （EM） absorption properties compared to the pristine graphene. The optimal reflection loss （RL） reaches -46.4 dB at 15.6 GHz with a thickness of only 1.4 mm for the Fe3O4/graphene composites obtained by applying 100 cycles of Fe2O3 deposition followed by a hydrogen reduction. The enhanced absorption ability arises from the effective impedance matching, multiple interfacial polarization and increased magnetic loss from the added magnetic constituents. Moreover, compared with other recently reported materials, the composites have a lower filling ratio and smaller coating thickness resulting in significantly increased EM absorption properties. This demonstrates that nanoscale surface modification of magnetic particles on graphene by ALD is a very promising way to design lightweight and high-efficiency microwave absorbers.展开更多
Significant progress has been made in the formulation of the functional nanomaterials with microemulsion phase.Microemulsion phase can be considered as true nanoreactors,which can be used to synthesize nanomaterials.P...Significant progress has been made in the formulation of the functional nanomaterials with microemulsion phase.Microemulsion phase can be considered as true nanoreactors,which can be used to synthesize nanomaterials.Properties and the mechanism of nanoparticle formation with microemulsion phase are reviewed in this paper.Preparation of the various nanomaterials,such as metal nanomaterials,oxide nanomaterials,magnetic nanoparticles,inorganic and inorganic compounds nanomaterials,metallic-organic composite nanomaterials,and other composite nanomaterials,are investigated with different microemulsion phases.The possible formation mechanisms are presented with the schematic diagram.展开更多
文摘An atomic layer deposition （ALD） method has been employed to synthesize Fe3O4/graphene and Ni/graphene composites. The structure and microwave absorbing properties of the as-prepared composites are investigated. The surfaces of graphene are densely covered by Fe3O4 or Ni nanoparticles with a narrow size distribution, and the magnetic nanoparticles are well distributed on each graphene sheet without significant conglomeration or large vacancies. The coated graphene materials exhibit remarkably improved electromagnetic （EM） absorption properties compared to the pristine graphene. The optimal reflection loss （RL） reaches -46.4 dB at 15.6 GHz with a thickness of only 1.4 mm for the Fe3O4/graphene composites obtained by applying 100 cycles of Fe2O3 deposition followed by a hydrogen reduction. The enhanced absorption ability arises from the effective impedance matching, multiple interfacial polarization and increased magnetic loss from the added magnetic constituents. Moreover, compared with other recently reported materials, the composites have a lower filling ratio and smaller coating thickness resulting in significantly increased EM absorption properties. This demonstrates that nanoscale surface modification of magnetic particles on graphene by ALD is a very promising way to design lightweight and high-efficiency microwave absorbers.
文摘Significant progress has been made in the formulation of the functional nanomaterials with microemulsion phase.Microemulsion phase can be considered as true nanoreactors,which can be used to synthesize nanomaterials.Properties and the mechanism of nanoparticle formation with microemulsion phase are reviewed in this paper.Preparation of the various nanomaterials,such as metal nanomaterials,oxide nanomaterials,magnetic nanoparticles,inorganic and inorganic compounds nanomaterials,metallic-organic composite nanomaterials,and other composite nanomaterials,are investigated with different microemulsion phases.The possible formation mechanisms are presented with the schematic diagram.
