Study On Polythiophene/Microcrystal Muscovite Conductive Mineral Compositie Materials

With the development and utilization of mineral resources, higher request and a wider range of applications of mineral material were put forward, prepared mineral materials with functional effects became a research trend gradually. Microcrystal muscovite is a layered silicate mineral with typical type 2M1, this mineral material has a good insulation, thermodynamic, mechanical, acid and alkali corrosion resistance performance, it was widely used in coatings, military and medicine. If combined with the conductive of functive and microcrystal, we will further expand the application of microcrystal muscovite.Polythiophene has a good optical, electrical and stability performance, what is more, its electrical conductivity value can be from insulator to good conductor, which make it has a good prospect in the capacitor, anti-corrosion, energy and other aspects. Thiophene recombined with layer muscovite can take advantage of synergies between of the two, which endow microcrystal muscovite with conductivity properties.In this paper, heat treatment, acid leaching process, lithium nitrate treatment and organically modification were taken to modified the layered microcrystal muscovite. Polythiophene/microcrystal muscovite composite materials were prepared by the method of intercalation polymerization with deionized water as a solvent and FeCl3 as initiator, explored of the anti-corrosio performance on metal for the composite material. The structure of microcrystal muscovite was analyzed by the method of X-ray diffraction(XRD), cation exchange capacity(CEC), infrared spectroscopy(FTIR) and other means. Thermal stability of materials were expolred by thermal gravimetric(TG), the morphology of materials were characterized by the scanning electron microscopy(SEM) and transmission electron microscopy analyzer(TEM), four-probe was used to test electrical conductivity of materials. At the same time, electrochemical analyzer was used to investigated corrosion resistance of the coatings on metal. The results showed that:(1) Thiophen entered into the modified microcrystal muscovite to polymerize in an aqueous solution, intercalation polythiophene/microcrystal muscovite composites were prepared successfully. The layer spacing of microcrystal muscovite increased to 2.28 nm after polymerization, the thermal stability of materials were improved.(2) The activation of microcrystal muscovite could be improved by means of heat-treated and acidification, the dissolution of Al3+ amount reached around 27.87mg/ g. Tation exchange capacity value increased significantly after lithium nitrate treatment, reaching at 42.73mmol/100 g. The layer spacing of muscovite was increased to1.94 nm after modification of cetyltrimethylammonium, the micro-enviro ment of layers were changed from hydrophilic to lipophilic. Modified microcrystal muscovite can improve the value of cation exchange capacity effectively and increase the interlayer spacing, at the same time change the interlayer hydrophily. All of these provided the realization of the material industrialization development.(3) With the increase of monomer ratio, reaction time and amount of the dopant, the conductivity of the composite materials showed a decreasing trend after the first increase, but the conductivity of composite materials decreased with increased reaction temperature. The highest conductivity of composite materials reached up to 7.23×10-3S.cm-1 when the monomer ratio was 1g/ml, the dopant in an amount of 0.7(relative to the Th monomer), the reaction temperature was 5? and the reaction time was 14 h. This process conditions is mild and easy to implement relatively, of which provided possibility to realize industrialization.(4) Polythiophene/microcrystal muscovite coating hade some electrochemical anti-corrosion on metal. The anti-corrosion of composite coating achieved the best when the monomer ratio was 1g/ml, the coating corrosion potential Ecorr was-0.478 v, the coating corrosion current density Icorr decreased 3 orders, the local impedance of electrode also improved 6 times relatively to other composite coating. The resistance value of composite coating increased when the immersion time closely to 7 day, the Ecorr increased and Icorr was 10-8.1. Polythiophene/microcrystal muscovite-epoxy exhibis some anticorrosion effect on metals.