The Study On The Preparation Of Ag/RGO/Polyaniline Composite And Its Electromagnetic Shielding Properties

Dendritic nanostructure silver has excellent electrical conductivity.Besides the trucks and lateral branches are rod-shape with high aspect ratio,which is easy to form conductive pathway.However,the silver is heavy and expensive,so it is introduced into carbon or conductive ploymer matrixes as filler to prepare electromagnetic shielding materials.Graphene has many advantages such as good conductivity,large specific surface area excellent mechanical properties,and the performance of microwave absorption.Polyaniline?PANI?has electrical conductivity after doping with protonic acid,besides which has many advantages such as lightweight,corrosion resistance,easy processing,so often is used as electromagnetic shielding material.In this paper,the composites of dendritic silver,reduced graphene oxide?RGO?and polyaniline were prepared,and their conductive properties and electromagnetic shielding propties were studied,the relevant results as follows:First of all,the effects of the dosage of clove oil,concentration of silver nitrate and ultrasonic time on the formation of dendritic silver nanostructure were investigated.The results show that the formation of dendritic silver nanostructure is mainly affected by the amount of clove oil and the concentration of AgNO₃,and the tightness of dendritic silver side branches is closely related to ultrasonic time.When the dosage of clove oil is2 mL,and the ultrasonic time was 3 h,the lateral branches of dendritic silver nanostructure were arranged symmetrically and tightly with high aspect ratio,and its electrical conductivity was 1.1×106S/cm.Secondly,the oxidized graphite was prepared by Hummers method,which was treated with ultrasonication,then mixed with silver nitrate solution to obtain dendritic Ag/RGO composite with different mass fraction of silver under ultrasonic condition.The results exhibit that the conductivity and shielding effectiveness of Ag/RGO composite increased with the increase of dendritic silver content,and the reflection loss account for a large proportion in the shielding effectiveness.When the silver content was 80 wt%,the shielding effectiveness of Ag/RGO composite at 0.2-3 GHz was 60 dB,and the reflection loss at 1 GHz was 45 dB.Finally,the Ag/RGO composites with different mass fraction of silver were filled in doped polyaniline with hydrochloric acid to prepare Ag/RGO/PANI composites.The conductivity and shielding properties of Ag/RGO/PANI composites filled with different mass fraction of Ag/RGO were discussed.The results reveal that the conductivity and shielding properties of Ag/RGO/PANI composites were increasing with the increase of the mass fraction of dendritic Ag/RGO,and the absorption loss account for a large proportion in the shielding effectiveness.When the polyaniline was filled with Ag/RGO at the mass fraction of 50 wt%,the Ag/RGO with 80 wt% silver,the total shielding effectiveness of Ag/RGO/PANI composite was 50 dB at 0.2-3 GHz and the absorption loss was 30 dB at 1 GHz.