Terahertz wave-absorbing material with gradient pore size structure and preparation method thereof

Abstract

The invention discloses a terahertz wave-absorbing material with a gradient pore size structure, and belongs to the technical field of terahertz wave absorption. The wave-absorbing material comprisesthree layers of three-dimensional graphene / PDMS composite materials, wherein the pore size range of the three-dimensional graphene on the uppermost layer is 100-120 [mu]m, the pore size range of the three-dimensional graphene in the middle is 50-70 [mu]m, and the pore size range of the three-dimensional graphene on the lowermost layer is 20-40 [mu]m. The terahertz wave-absorbing material disclosedby the invention has an extremely strong broadband terahertz wave absorption characteristic, and the average absorption rate in an ultra-wideband frequency spectrum range of 0.2-1.2 THz is as high as93% or above; the terahertz wave-absorbing material has ultrathin thickness, and the thickness of each layer is controlled within 1mm, so that the total thickness of the terahertz wave-absorbing material is within 3 mm, which is far superior to that of existing terahertz wave-absorbing foam materials; the terahertz wave-absorbing material has extremely good flexible characteristics such as bendability, stretchability and mechanical elasticity; raw materials are cheap, the preparation method is simple, and large-area preparation can be realized.

Description

technical field [0001] The invention belongs to the technical field of terahertz absorbing, and in particular relates to a three-dimensional graphene / PDMS terahertz absorbing material with a gradient aperture structure and a preparation method thereof. Background technique [0002] Terahertz (THz, 1THz=10 12 Hz) waves refer to electromagnetic waves with a frequency between 0.1THz-10THz and a wavelength between 0.03mm-0.3mm. Terahertz waves lie between infrared and millimeter waves in frequency. In the electromagnetic spectrum, the research on infrared technology and microwave technology has been very mature, but the research on terahertz wave is still in progress and has not been fully developed and applied. In recent years, with the rapid development of terahertz radiation sources and terahertz detectors, the progress of terahertz technology has gradually accelerated, showing great scientific value in the fields of physics, biology, astronomy, national defense, and mobile...

AI Technical Summary

Problems solved by technology

However, there are two problems in this porous 3D graphene foam: 1) The influence of the pore size on the absorption characteristics must be effectively balanced. If the pore size is too small, the incidence of terahertz waves will be blocked, and the reflection on the surface of the material will be enhanced, thus reducing the absorption capacity; and If the pore size is too large, the attenuation effect of the terahertz wave inside the material will be reduced, so the thickness of the absorbing material has to be increased to increase the absorption rate

Because the existing 3D foam terahertz wave absorbing material adopts a single pore size, a compromise must be made between the absorption efficiency and thickness, and the best material performance cannot be achieved; 2) Because the highly conductive 3D graphene foam needs to pass through High-temperature annealing treatment, which makes the foam very brittle and has no flexible functions such as stretching, bending and pressure resistance, and its actual use effect is greatly limited

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