Preparation And Study Of Reduced Graphene Oxide/ferric Oxide/polyaniline Absorbing Wave Anticorrosive Nanocomposites

The functional anti-corrosion coating is the key research direction in the field of coatings,and with the development of radar detection technology,the stealth anticorrosive coating has become the focus of research in many countries.The key technology of stealth anticorrosive coating is to prepare a kind of material which has both wave absorption and anti-corrosion resistance.Polyaniline,grapheme and Fe₃O₄ are the dominant materials in the field of absorbing and anti-corrosion.However,it is difficult for a single material to meet all requirements,such as absorption,anti-corrosion,light weight and stability.Therefore,it is an important method to solve the difficult problem that designing unique structure by composition material.In the work,using graphene oxide as basic raw materials,it studies nanocomposite multilayer assembly principle that polyaniline?PANI?coats with reduced graphene oxide?rGO?which loaded ferroferric oxide?Fe₃O₄?synthesis,the microwave absorbing property and anti-corrosion performance.Then we focus on the corrosion resistance and anticorrosion mechanism of rGO/Fe₃O₄/PANI aqueous coatings.Specific research contents are as follows:1.Using graphene oxide as basic raw materials,the rGO/Fe₃O₄ composites was prepared by coordination assembly principle using aniline as reducing agent fristly.Then,the rGO/Fe₃O₄/PANI three element nanocomposite was prepared by oxidation polymerization of aniline on the surface of the suspension dispersed nanoparticles.Its structure and morphology of composition were tested by X ray diffraction?XRD?,thermal gravimetric analysis?TG?,infrared spectroscopy?FT-IR?,scanning electron microscopy?SEM?and transmission electron microscopy?TEM?,etc.The results show that the rGO/Fe₃O₄/PANI composite has multi layer interface morphology,which can be controlled by component proportion.And UV spectrum analysis?UV-vis?and X-ray photoelectron spectroscopy?XPS?measurements are testedd and they reveal that the interfacial interactions among the components in rGO/Fe₃O₄/PANI composites are coordination interaction and ?-? stacking interaction.The performance tests of rGO/Fe₃O₄/and PANI show that the composite has ferromagnetism and redox activity.2.It studies the ratio of rGO and Fe₃O₄ in the composite effect of absorbing performance,and the results show that when the weight ratio of rGO/Fe₃O₄ is 3:7,the impedance matching of the best,the minimum reflection loss value of RL reached-35dB with the thickness of 2mm and the absorption bandwidth is close to 4GHz.Comparing to pure Fe₃O₄,the electromagnetic loss display significantly.Fixing weight ratio of rGO/Fe₃O₄ to 3:7,it studies the effect of PANI content on the shell for absorbing performance,which show that when the weight ratio of rGO/Fe₃O₄/PANI to 3:7:6,the impedance matching is best.The minimum reflection loss value of RL reached-50dB with the thickness of 2.5mm and the absorption bandwidth of nearly 4.1GHz.Comparing with the rGO/Fe₃O₄ composites,the rGO/Fe₃O₄/PANI composites has better wave absorbing property.Because the impedance matching of rGO/Fe₃O₄/PANI composite is better,and the formation of the multilayer interface structure prolongs the dielectric relaxation process to improve the absorbing property.3.In order to study the anticorrosion mechanism of rGO/Fe₃O₄/PANI?3:7:6?composites,the waterborne nano acrylic resin coatings were prepared with rGO/Fe₃O₄/PANI composites with filling amount of 3wt%,using rGO/Fe₃O₄?3:7?as reference.The results show that,comparing to the unfilled coating,nano composites system filled with salt fog,acid and alkali resistance is obviously improved,and the mechanical properties and chemical resistant of rGO/Fe₃O₄/PANI filling coating was better than rGO/Fe₃O₄ filling coating.To further explore its mechanism,Tafel polarization curves?Tafel Plot?and electrochemical impedance spectroscopy?EIS?were used to characterize.The results show that compared to the unfilled coating,the rGO/Fe₃O₄ filling coating have good barrier properties,while rGO/Fe₃O₄/PANI filling coating not only has the barrier properties,after electrochemical corrosion occurring,the polyaniline also rGO/Fe₃O₄/PANI composites uses its redox activity to form a dense passivating film effectively on the metal surface?by X-ray photoelectron spectroscopy?XPS?characterization?and the thickness of the passive film is affected by the pH value of the corrosion medium.Therefore,this paper reveals that the anticorrosion mechanisms of rGO/Fe₃O₄/PANI nanocomposite are the high performance barrier of graphene and the electrochemical smart passivation effect of PANI.