A preparation method of composite airgel functional material based on ferric oxide nanowire/graphene oxide interpenetrating structure

Abstract

A composite airgel functional material based on ferroferric oxide nanowire / graphene oxide interpenetrating structure and a preparation method thereof belong to the field of wave-absorbing functional materials. The invention is based on a one-pot hydrothermal method, selects a non-ionic surfactant to control the growth of ferric oxide in one dimension and regulates the dispersion state of GO solution and nanowires, and uses monodentate thiosulfate to regulate the precipitation reaction speed and reduce with iron To a certain extent, GO was assembled in situ by multifunctional biomass reducing agent; the composite hydrogel was processed to form dense ice crystals by batch cycle freeze-drying, and a new type of Fe3O4 nanowire / graphene airgel interpenetrating was prepared. Structural composite materials, thus forming a uniformly dispersed wave-absorbing material that integrates multi-dimensional scales, giving full play to its electric and magnetic losses, and using coupling effects, interface effects, and impedance matching characteristics to obtain excellent wave-absorbing properties. The function loss mechanism has a strong absorption of electromagnetic wave broadband, which can effectively solve problems such as electromagnetic pollution.

Description

technical field [0001] The invention belongs to the field of wave-absorbing functional materials, and mainly relates to a preparation method of a composite airgel functional material based on ferric oxide nanowire / graphene oxide interpenetrating structure. Background technique [0002] At present, with the widespread use of various electronic devices and components, the safety hazards brought by electromagnetic wave radiation are also deepening day by day, causing adverse effects on people's health. Microwave absorbing materials can effectively absorb electromagnetic waves, convert electromagnetic energy into heat energy, or dissipate electromagnetic waves through interference, so they have attracted widespread attention. Traditional electromagnetic wave absorbing materials, such as ferrite and conductive polymers, have strong microwave absorption properties and can effectively absorb electromagnetic waves. However, these materials have disadvantages such as high density, e...

AI Technical Summary

Problems solved by technology

Chinese patent [Application No. 201811100210.2] discloses a preparation method of nitrogen-doped reduced graphene oxide airgel absorbing material. Although the graphene airgel is assembled in situ by a simple one-step method, its electromagnetic wave absorption and reflection Loss is only -15dB, poor absorbing performance

However, the preparation process of this invention is relatively long, the dispersion of nanoparticles in graphene airgel needs to be optimized, and the overall absorbing performance is low

[0004] In general, the problems of the wave-absorbing materials reported in the literature are as follows: first, a single graphene aerogel with high conductivity and weak magnetism and a single trioxide tetroxide with high magnetism and weak conductivity Both iron nanowires have the problem of impedance mismatch, and the overall absorbing performance of the two materials is not good; second, the preparation process of the composite absorbing material of graphene and ferroferric oxide nanoparticles is complicated, and it is difficult to meet the needs of industrial production; The magnetic nanoparticles are poorly dispersed and easy to agglomerate, which limits the performance of the composite system; the fourth is that the carbon substrates in carbon-based absorbing materials are usually one-dimensional or two-dimensional structures. Compared with three-dimensional structures, they provide electromagnetic wave reflection inside the material. At the same time, the conductivity is low because no conductive network is formed; fifth, the absorption of electromagnetic waves by nanoparticles only comes from magnetic loss and weak interface polarization loss

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