An Ecofriendly, Cost-Effective, Lightweight Microwave Absorber Based on Waste Toner

This work presents the design of an inexpensive environment-friendly and lightweight microwave absorber based on waste toner. MnNiZn ferrite/waste toner microwave absorbing composites were prepared, where waste toner serves both as host matrix and microwave absorber (active matrix). The structural characterization of the composite was investigated using x-ray diffractometry and FTIR spectroscopy. The magnetic characterization and microwave absorption characteristics in the S- and C-bands (2–8 GHz) were measured by a vibrating sample magnometer (VSM) and a vector network analyzer (VNA), respectively. The results showed a beneficial role of using waste toner in enhancing the microwave absorption performance of the composites in comparison with ferrite alone but in a passive matrix, such as paraffin. The optimized absorbers were obtained using 40 w% waste toner and of 60 w% MnNiZn ferrite. The absorber of the largest bandwidth of 4.55 GHz was obtained at a matching thickness of 6.0 mm and a minimum reflection loss (RL) of − 18 dB at the matching frequency of 5.05 GHz. The absorber of the same composition that shows the lowest minimum RL of − 22.5 dB has a matching thickness of 5.0 mm and a matching frequency of 6.31 GHz with a bandwidth of 3.5 GHz.