Microwave absorption performance of hexagonal nano boron nitride doped basalt fabric-reinforced epoxy composites

2021 ◽  
Vol 93 (1) ◽  
pp. 205-211
Author(s):  
Fatma Bakal ◽  
Ahmet Yapici ◽  
Muharrem Karaaslan ◽  
Oğuzhan Akgöl

Purpose The purpose of this paper is to investigate the effect of doping element on the microwave absorption performance of hexagonal nano boron nitride (h-nBN)-reinforced basalt fabric (BF)/epoxy composites. A new type of hybrid composite that will be produced by the use of boron nitride as an additive that leads to increased radar absorption capability will be developed and a new material that can be used in aeronautical radar applications. Design/methodology/approach This study is focused on the microwave absorption properties of h-nBN doped basalt fabric-reinforced epoxy composites. Basalt fabric (BF)/epoxy composites (pure composites) and the BF/h-nBN (1 Wt.% h-nBN doped composites) hybrid composites were fabricated by vacuum infusion method. Phase identification of the composites were performed using X-ray diffraction (XRD), the 2θ scan range was from 10 to 60 with the scanning speed of 3°/min and surface morphologies of the composites were investigated using scanning electron microscopy (SEM). Microwave properties of samples were investigated through transmission/reflection measurements in Agilent brand 2-Port PNA-L Network Analyzer in the frequency range of 3–18 GHz. The prepared sample is positioned between two horn antennas with and without metal plate. Findings Experimental results show that h-nBN doped composite was synthesized successfully and the produced hexagonal nano boron nitride-added fiber laminated composite material has good absorption behavior when they are used with metallic sheets and good for isolation applications at many points in the 3–18 GHz band. Originality/value This paper will contribute to the literature on the use of basalt fabric, which are new types of fibers, and hexagonal nano boron nitride and the effects of boron nitride on radar absorption properties of composite material. It presents detail characterization of each composite by using XRD and scanning electron microscopy.

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2921 ◽  
Author(s):  
Wei Huang ◽  
Yujiang Wang ◽  
Shicheng Wei ◽  
Bo Wang ◽  
Yi Liang ◽  
...  

Hollow magnetic structures have great potential to be used in the microwave absorbing field. Herein, Fe3O4 hollow spheres with different levels of hollowness were synthesized by the hydrothermal method under Ostwald ripening effect. In addition to their microstructures, the microwave absorption properties of such spheres were investigated. The results show that the grain size and hollowness of Fe3O4 hollow spheres both increase as the reaction time increases. With increasing hollowness, the attenuation ability of electromagnetic wave of Fe3O4 spheres increases first and then decreases, finally increases sharply after the spheres break down. Samples with strong attenuation ability can achieve good impedance matching, which it does preferentially as the absorber thickness increases. Fe3O4 hollow spheres show the best microwave absorption performance when the reaction time is 24 h. The minimum reflection loss (RL (min)) can reach −40 dB, while the thickness is only 3.2 mm.


2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Yangyang Gu ◽  
Peng Dai ◽  
Wen Zhang ◽  
Zhanwen Su

AbstractIn this work, we demonstrated a simple method for preparing three-dimensional interconnected carbon nanofibers (ICNF) derived from fish bone as an efficient and lightweight microwave absorber. The as-obtained ICNF exhibits excellent microwave absorption performance with a maximum reflection loss of –59.2 dB at the filler content of 15 wt%. In addition, the effective absorption bandwidth can reach 4.96 GHz at the thickness of 2 mm. The outstanding microwave absorption properties can be mainly ascribed to its well-defined interconnected nanofibers architecture and the doping of nitrogen atoms, which are also better than most of the reported carbon-based absorbents. This work paves an attractive way for the design and fabrication of highly efficient and lightweight electromagnetic wave absorbers.


RSC Advances ◽  
2016 ◽  
Vol 6 (60) ◽  
pp. 55546-55551 ◽  
Author(s):  
Shu-Qing Lv ◽  
Ya-Fei Pan ◽  
Pei-Bo Yang ◽  
Guang-Sheng Wang

By using a simple wet chemical method and hot-molding procedure, a kind of flexible film with enhance absorption properties based on binary cobalt nanochains/polyvinylidene fluoride (PVDF) hybrids has been successfully fabricated.


RSC Advances ◽  
2019 ◽  
Vol 9 (53) ◽  
pp. 30685-30692 ◽  
Author(s):  
Sifan Zeng ◽  
Wanlin Feng ◽  
Shuyuan Peng ◽  
Zhen Teng ◽  
Chen Chen ◽  
...  

The SiOC ceramics coating modified carbon fibers improved anti-oxidation and refine microwave absorption properties.


2013 ◽  
Vol 631-632 ◽  
pp. 78-81 ◽  
Author(s):  
Xiao Jing Yang ◽  
Lan Lan Li ◽  
Xin Hua Zhang ◽  
Pan Shi ◽  
Yue Tian ◽  
...  

We reported on a convenient route to synthesize rhombohedra boron nitride (r-BN) micro-rod using urea (CO(NH2)2) and sodium borohydride (NaBH4) through thermal treatment at 1300 °C. The structure, morphology, and chemical composition of the obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). In order to determine the phase composition and abundance of the as-synthsized simples, Rietveld refinement has been performed to analyze the XRD data using the Rietan-2000 program. The results show that the abundance of r-BN is about 90.6 wt % and h-BN is 9.4 wt % deduced from Reitveld refinement.


2015 ◽  
Vol 81 (17) ◽  
pp. 5794-5803 ◽  
Author(s):  
Komlavi Anani Afanou ◽  
Anne Straumfors ◽  
Asbjørn Skogstad ◽  
Ajay P. Nayak ◽  
Ida Skaar ◽  
...  

ABSTRACTSubmicronic fungal fragments have been observed inin vitroaerosolization experiments. The occurrence of these particles has therefore been suggested to contribute to respiratory health problems observed in mold-contaminated indoor environments. However, the role of submicronic fragments in exacerbating adverse health effects has remained unclear due to limitations associated with detection methods. In the present study, we report the development of an indirect immunodetection assay that utilizes chicken polyclonal antibodies developed against spores fromAspergillus versicolorand high-resolution field emission scanning electron microscopy (FESEM). Immunolabeling was performed withA. versicolorfragments immobilized and fixed onto poly-l-lysine-coated polycarbonate filters. Ninety percent of submicronic fragments and 1- to 2-μm fragments, compared to 100% of >2-μm fragments generated from pure freeze-dried mycelial fragments ofA. versicolor, were positively labeled. In proof-of-concept experiments, air samples collected from moldy indoor environments were evaluated using the immunolabeling technique. Our results indicated that 13% of the total collected particles were derived from fungi. This fraction comprises 79% of the fragments that were detected by immunolabeling and 21% of the spore particles that were morphologically identified. The methods reported in this study enable the enumeration of fungal particles, including submicronic fragments, in a complex heterogeneous environmental sample.


2018 ◽  
Vol 6 (36) ◽  
pp. 9615-9623 ◽  
Author(s):  
Dawei Liu ◽  
Yunchen Du ◽  
Zhennan Li ◽  
Yahui Wang ◽  
Ping Xu ◽  
...  

Three-dimensional flower-like Ni microspheres with enhanced microwave absorption performance can be easily synthesized through a simple precursor-directed method.


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