Physico-Chemical nanomaterials science

Effect of the bromination method of PAN carbon fibers on their interaction with ultrahigh-frequency electromagnetic radiation
Dovgan О.M.1, Moiseienko V.A.1, Trachevskyi V.V.2, Mischanchuk O.V.3, Diyuk V.E.1, Lisnyak V.V.1, Grishchenko L.M.1
1 Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska St., Kyiv-01601, Ukraine. liudmyla.grishchenko@gmail.com
2 Institute of Macromolecular Chemistry of NAS of Ukraine, Kharkivsʹke avenue, 48, Kyiv-02160, Ukraine.
3 O.O. Chuiko Institute of Surface Chemistry, NAS of Ukraine, Henerala Naumova St., 17, Kyiv-03164, Ukraine.

Carbon materials are widely used to obtain composite materials for personal protective equipment [1].  This work aimed to compare the effect of two bromination methods on the radio absorption properties of the resulting PAN-carbon fibers. We studied how the bromine modifier concentration impacts the magnitude of the attenuation of the power of electromagnetic radiation S21 and the voltage standing wave ratio (VSWR) in a wide frequency range for the samples of the brominated PAN-carbon fibers with a thickness of a single layer.  We suggested that for the brominated PAN-carbon fibers obtained by the plasma chemical and the liquid phase methods, there is an "optimal" value of bromine concentration. Clearly, after reaching a certain amount of bromine in the composition of the brominated PAN-carbon fibers, all subsequent bromine addition has no prominent effect on the absorbing properties. They even harm the sample leading to wasteful use of the bromine modifier. In addition, the law of saturation of PAN-carbon fibers with bromine is the same for both modification methods. There is a general similarity in the behavior of modified PAN-carbon fibers with an increase in the frequency of electromagnetic radiation: the magnitude of the power attenuation S21 increases while VSWR decreases.

1.	Hu, P., Dong, S., Li, X., Chen, J., Zhang, X., Hu, P., & Zhang, S. A. low−cost strategy to synthesis MnO nanorods anchored on 3D biomass−derived carbon with superior microwave absorption properties // J Mater Chem C. -2019. -7, N 30. -P. 9219-9228.