scholarly journals Light-induced levitation of ultralight carbon aerogels via temperature control

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.

scholarly journals Environmentally Friendly and Multifunctional Shaddock Peel-Based Carbon Aerogel for Thermal-Insulation and Microwave Absorption

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Weihua Gu ◽  
Jiaqi Sheng ◽  
Qianqian Huang ◽  
Gehuan Wang ◽  
Jiabin Chen ◽  
...  
Keyword(s):  
Microwave Absorption ◽  
Thermal Insulation ◽  
Freeze Drying ◽  
Thermal Infrared ◽  
Carbon Aerogel ◽  
Carbon Aerogels ◽  
List Type ◽  
Drying Method ◽  
Cross Sectional ◽  
Compression Resistance

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.

Ultramicroporous carbon aerogels encapsulating sulfur as the cathode for lithium–sulfur batteries

2021 ◽  
Author(s):  
Maryam Nojabaee ◽  
Brigitta Sievert ◽  
Marina Schwan ◽  
Jessica Schettler ◽  
Frieder Warth ◽  
...  
Keyword(s):  
Carbon Aerogel ◽  
Composite Cathode ◽  
Microporous Carbon ◽  
Carbon Aerogels ◽  
Lithium Sulfur Batteries ◽  
Lithium Sulfur

In the presented study, a sulfur infiltrated ultra-microporous carbon aerogel as a composite cathode for lithium sulfur batteries is developed and investigated.

Fe ultra-small particles anchored on carbon aerogels to enhance the oxygen reduction reaction in Zn-air batteries

2021 ◽  
Author(s):  
Jinjin Shi ◽  
Xinxin Shu ◽  
Chensheng Xiang ◽  
Hong Li ◽  
Yang Li ◽  
...  
Keyword(s):  
Oxygen Reduction Reaction ◽  
Oxygen Reduction ◽  
Active Sites ◽  
Carbon Aerogel ◽  
Reduction Reaction ◽  
Superior Performance ◽  
Carbon Aerogels ◽  
Small Particles

The Fe–N4–O–Fe–N4 moiety as active sites in ultra-small Fe particles anchored on carbon aerogel exhibited superior performance towards the oxygen reduction reaction.

Ti3C2MXenes modified with in situ grown carbon nanotubes for enhanced electromagnetic wave absorption properties

2017 ◽  
Vol 5 (16) ◽  
pp. 4068-4074 ◽  
Author(s):  
Xinliang Li ◽  
Xiaowei Yin ◽  
Meikang Han ◽  
Changqing Song ◽  
Hailong Xu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electromagnetic Wave ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Absorption Properties ◽  
Electromagnetic Wave Absorption ◽  
Catalytic Chemical Vapor Deposition ◽  
Wave Absorption

Ti3C2TxMXenes modified within situgrown carbon nanotubes (CNTs) are fabricatedviaa simple catalytic chemical vapor deposition (CVD) process.

scholarly journals Absorption Properties of Hybrid Composites of Gold Nanorods and Functionalized Single-Walled Carbon Nanotubes

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Deok-Jin Yu ◽  
D. Ganta ◽  
Elijah Dale ◽  
A. T. Rosenberger ◽  
James P. Wicksted ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Absorption Spectra ◽  
Self Assembly ◽  
Hybrid Composites ◽  
Single Walled Carbon Nanotubes ◽  
Plasmon Mode ◽  
Absorption Properties ◽  
Au Nanorods ◽  
Single Walled Carbon ◽  
Walled Carbon Nanotubes

We report on the optical properties of fabricated nanohybrid structures containing Au nanorods and functionalized single-walled carbon nanotubes in aqueous solutions. In particular, the absorption spectra of these hybrid materials are studied as a function of the concentration of the functionalized single-walled carbon nanotubes as well as the evolution time following preparation. The absorption spectra show a red shift of the longitudinal plasmon mode of the Au nanorods along with the emergence of broadened structures at wavelengths between 1000 and 1100 nm. These results, supported by TEM images, indicate the self-assembly of the Au nanorods forming on the sidewalls of the functionalized SWNTs driven by polyelectrolyte interactions.

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