Covalent Functionlization Hybrids Of Graphene And Azobenzene And Its Influence On The Electromagnetism Of Fe₃O₄ Nano-particles

Azobenzene derivatives (collectively referred to as "azo" in the following) is a kind of photosensitive molecule.Under the irradiation of UV light,AZO transitions from trans to cis to store energy.Some research shows that the close-packed and highly ordered array of adsorbed AZO molecules imposed by the CNT substrate can improve the energy storage density and stability of the materials.We present a new synthetic method of synthesizing AZO/GO hybrids,which realizes AZO molecules directly attach to GO substrates by-N=N-groups,making carbon six rings of GO to be a part of AZO molecules.The method is simple and convenient and fit for large scale production.In order to achieve a goal of controlling the hybrids’energy storage density,GO substrates are reduced to control the amount of the covalent linkage AZO molecules. It turns out that the reduced GO substrates can also obtain a set of hybrid nanostructures composed of AZO molecules covalently attach to RGO substrates by -N=N-groups. The more GO substrates are reduced, the more covalent linkage AZO molecules and the higher energy storage density are obtained, providing a feasible method of controlling the hybrids’energy storage density. The photoisomerization of the hybrids shows that it can keep stable for 100 days when settled in darkness after the irradiation, which confirms the hybrids has a higher thermal barrier Ea and the stability is satisfied. In addition, the electromagnetic property of the hybrids is tested under microwave frequency range. It turns out The photoisomerization of AZO molecules has a significant influence on the electromagnetic property of the hybrids. Fe3O4GO and Fe3O4/GO-AZO composites are synthesized by a solvothermal reaction, which is to make clear that if AZO covalently bound to GO substrates takes a role in the magnetism of GO-AZO/Fe3O4 composites. It turns out that AZO molecules on GO substrates have no obviously influence on the grain sizes and magnetism of Fe3O4 particles. But AZO molecules on GO substrates can effectively reduce the plural conductivity of the hybrids, making Fe3O4GO-AZO composites keep stable dielectric loss in a wide scope, meanwhile increasing the impedance matching degree of electromagnetic parameters of the hybrids, which makes Fe3O4/GO-AZO composites a kind of potential broadband adsorbing agent.The results provide an important theoretical and experimental basis about the demonstration, the structure and the controllable energy storage density of the AZO/GO hybrids, and also predict the potential application of this hybrid in electromagnetic wave absorption.