Carbon nanotubes regulated hollow skeleton carbon aerogel for effective thermal insulation and favorable mechanical behavior

Highlights The eco-friendly shaddock peel-derived carbon aerogels were prepared by a freeze-drying method. Multiple functions such as thermal insulation, compression resistance and microwave absorption can be integrated into one material-carbon aerogel. Novel computer simulation technology strategy was selected to simulate significant radar cross-sectional reduction values under real far field condition. . Abstract Eco-friendly electromagnetic wave absorbing materials with excellent thermal infrared stealth property, heat-insulating ability and compression resistance are highly attractive in practical applications. Meeting the aforesaid requirements simultaneously is a formidable challenge. Herein, ultra-light carbon aerogels were fabricated via fresh shaddock peel by facile freeze-drying method and calcination process, forming porous network architecture. With the heating platform temperature of 70 °C, the upper surface temperatures of the as-prepared carbon aerogel present a slow upward trend. The color of the sample surface in thermal infrared images is similar to that of the surroundings. With the maximum compressive stress of 2.435 kPa, the carbon aerogels can provide favorable endurance. The shaddock peel-based carbon aerogels possess the minimum reflection loss value (RLmin) of − 29.50 dB in X band. Meanwhile, the effective absorption bandwidth covers 5.80 GHz at a relatively thin thickness of only 1.7 mm. With the detection theta of 0°, the maximum radar cross-sectional (RCS) reduction values of 16.28 dB m2 can be achieved. Theoretical simulations of RCS have aroused extensive interest owing to their ingenious design and time-saving feature. This work paves the way for preparing multi-functional microwave absorbers derived from biomass raw materials under the guidance of RCS simulations.

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06/01093 Mechanical behavior and microstructure of cement composites incorporating surface-treated multiwalled carbon nanotubes

Fuel and Energy Abstracts ◽

10.1016/s0140-6701(06)81097-0 ◽

2006 ◽

Vol 47 (3) ◽

pp. 166

Keyword(s):

Carbon Nanotubes ◽

Mechanical Behavior ◽

Multiwalled Carbon Nanotubes ◽

Cement Composites ◽

Multiwalled Carbon

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Light-induced levitation of ultralight carbon aerogels via temperature control

Scientific Reports ◽

10.1038/s41598-021-91918-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Reo Yanagi ◽

Ren Takemoto ◽

Kenta Ono ◽

Tomonaga Ueno

Keyword(s):

Carbon Nanotubes ◽

Heat Capacity ◽

Porous Materials ◽

Temperature Control ◽

Light Absorption ◽

Carbon Aerogel ◽

Carbon Aerogels ◽

Halogen Lamp ◽

Absorption Properties ◽

Air Density

AbstractWe demonstrate that ultralight carbon aerogels with skeletal densities lesser than the air density can levitate in air, based on Archimedes' principle, when heated with light. Porous materials, such as aerogels, facilitate the fabrication of materials with density less than that of air. However, their apparent density increases because of the air inside the materials, and therefore, they cannot levitate in air under normal conditions. Ultralight carbon aerogels, fabricated using carbon nanotubes, have excellent light absorption properties and can be quickly heated by a lamp owing to their small heat capacity. In this study, an ultralight carbon aerogel was heated with a halogen lamp and levitated in air by expanding the air inside as well as selectively reducing its density. We also show that the levitation of the ultralight carbon aerogel can be easily controlled by turning the lamp on and off. These findings are expected to be useful for various applications of aerogels, such as in communication and transportation through the sky.

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