Abstract-Terahertz absorption in graphite nanoplatelets/polylactic acid composites

Dzmitry Siarheevich Bychanok, Polya Angelova, Alesia Paddubskaya, Darya Meisak, Lizaveta Shashkova, Marina Demidenko, Artyom Plyushch, Evgeni Ivanov, Rumen Krastev, Rumiana Kotsilkova

http://iopscience.iop.org/article/10.1088/1361-6463/aab1a5/pdf

The electromagnetic (EM) properties of composite materials based on poly(lactic) acid (PLA) filled with graphite nanoplatelets (GNP) were investigated in the microwave (26-37 GHz) and terahertz (0.2-1 THz) frequency ranges. The maximum of imaginary part of dielectric permittivity was observed close to 0.6 THz for composites with 1.5 and 3 wt.% of GNP. The experimental data of complex dielectric permittivity of GNP/PLA composites was modelled using Maxwell-Garnett theory. The effects of fine dispersion, agglomeration, and percolation in GNP-based composites on its electromagnetic constitutive parameters, presence, and position of THz absorption peak are discussed on the basis of modeling results and experimental data. The unique combination of conductive and geometrical parameters of GNP embedded into the PLA matrix below the percolation threshold allow obtaining THz-absorptive material, which may be effectively used as 3D-printing filament.