In a study published in Advanced Materials Interfaces, a research group led by Professor WANG Hui and Associate Professor. SHENG zigao from the Hefei Institutes of Physical Sciences (HFIPS) of the Chinese Academy of Sciences reported the synthesis of polyvinylpyrrolidone (PNNW) guided nickel nanowires (Nickel nanowires improve microwave absorption) through a high magnetic-assisted solvothermal method, and applied to increase the absorption of microwaves.
Among the many microwaves that have been studied, single-dimensional magnetic nanowires have attracted much attention due to their excellent mechanical properties, large dimensions and good electron transfer performance. However, the flat surface and insufficient magnetism of nickel nanowires produced by conventional methods prevent the process of electromagnetic waves (EW) passing through the heated material and spreading as heat energy. Therefore, it is necessary to urgently find a new method to increase the height and magnetic properties of nickel nanowires and to improve the microwave transmission efficiency.
In this study, the researchers used the solvothermal method of the magnetic field to produce PNNW, and the morphology and properties of PNNW showed a relationship based on the strength of the magnetic field.
9T-PNNW synthesized with 9 T (tesla) magnet has high aspect ratio, high surface area and better magnetic properties, giving it good microwave reception performance. When the thickness is 4.5 mm, the minimum reflection (29.82 dB) is obtained at 4.08 GHz. When the thickness is 1.5mm, the effective absorption bandwidth from 14.4GHz to 18.0GHz can exceed 3.6GHz.
This makes the electromagnetic interference system different to reduce the electromagnetic waves, among which the dielectric loss is controlled, while the magnetic loss, current loss and resonance effect play an auxiliary role, according to the researchers said.
This work opens a new way for the rational design and preparation of nickel nanowires, and more importantly, the magnetic field has important reference for the design of attractive performance.
