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The effect of temperature on structure and permittivity of carbon microspheres as efficient absorbent prepared by facile and large-scale method.
- Source :
-
Carbon . Nov2021, Vol. 185, p650-659. 10p. - Publication Year :
- 2021
-
Abstract
- Based on the concept of environment-friendly development strategy, green preparation method is crucial. Therefore, starch-derived micron solid carbon spheres (SCs) were fabricated via spray-drying followed by carbonization processing, in which is no any harmful substances in whole process. Through tuning the carbonization temperature, SCs with a moderate degree of graphitization and intrinsic defects can be obtained. The microstructure, permittivity and microwave absorption of SCs were studied. Results show that the SCs with a larger number of micropores is composed of nanocrystalline regions and amorphous areas. The paraffin-based composites with 25 wt% SCs carbonized at 800 °C displays a strong microwave loss feature, the minimum reflection loss of −64.8 dB at 9.02 GHz with thickness of 2.57 mm. Meanwhile, the effective absorption band (<-10 dB) can reach 3.1 GHz with the thickness of 2.22 mm, covering 78% of X-band, which because of its good impedance matching and dielectric loss ability resulted from the synergistic effect between the microstructure and graphitization. This work offers a facile, larger-scale and environmental-friendly method for the preparation of micron carbon-based absorbents that can serves as an alternative to nano-scale absorbents to overcome the poor dispersion of nanoparticle in the matrix. [Display omitted] • Starch-derived micron solid carbon sphere with complex nano-scale structure was fabricated by facile and large-scale method. • The micron sphere carbonized at different temperature exhibits a strong absorption of the RL min of −64.8 dB at 9.02 GHz. • Carbon microspheres can be served as an alternative to nanoscale fillers to overcome poor dispersion in the matrix. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00086223
- Volume :
- 185
- Database :
- Academic Search Index
- Journal :
- Carbon
- Publication Type :
- Academic Journal
- Accession number :
- 153292970
- Full Text :
- https://doi.org/10.1016/j.carbon.2021.09.070