Preparation And Characteristic Of Composite Conductive Powders And Coating With Barite Matrix

Tin oxide (SnO₂) is a insulator and the energy gap is 3.8eV, it is a kind of n-type semiconductor by the addition of adequate doping atoms, such as Sb, F or In. Sb-doped tin oxide(ATO) nanomaterials with electricity and optics properties, have been widely applied in many fields including solar battery, intelligence windowstransparent conductor, antistatic plastic, electrochromism materials, coating, fiber, antistatic layer, gas sensor, electrode materials and so on. F-doped tin oxide (FTO) nanomaterials play an important role in the fields of glass electrode, informational materials and sensitive materials, especially the FTO film can improve the conductivity and transmittance in comparison with the SnO₂ films.In this paper, Sb₂O₃, SnO₂, Sb-SnO₂, F-SnO₂ nanomaterials were synthesized by precipitation method from the starting materials chloride, and Sb-SnO₂ and F-SnO₂ nanoparticles were deposited on barite (BaSO₄) to produce Sb-SnO₂/BaSO₄ (SSB) composite conductive powders and F-SnO₂/BaSO₄ (FSB) via a chemical liquid deposition method. The obtained SSB conductive powders were made as the fillers in the conductive coatings and showed better conductivity, better dispersion, resistance to corrosion and the flat surface.Sb₂O₃ nanoparticles have been successfully synthesized via hydrolysis-precipitation method, and the sample shows rod-like structure and has a preferred directional growth. With increasing the reaction temperature, the partial cubic phase completely changed to be orthorhombic phase at 60℃, and the crystal size of particles and the lattice parameters changed correspondingly. The mechanism of hydrolysis has been discussed and the electrochemical behaviors have been investigated by cyclic voltammetry in lithium hexafluorophosphate (LiPF₆) solution.Sb-SnO₂ nanoparticles have been synthesized by co-precipitation method from the starting materials antimony chloride (SbCl₃) and stannic chloride hydrate (SnCl₄·5H₂O), when the Sb doping SnO₂, there is not the second phase, the crystalline structure tends towards integrity with the increase of treatment temperature. The SSB composite conductive powders were prepared via a chemical liquid deposition method. Effects of different experimental factors on the resistivity of the SSB composite powders were primarily investigated, especially the doping concentration of antimony has great effect on resistivity, there are two states Sb³⁺ and Sb⁵⁺, when the antimony concentration was 8%, the resistivity of SSB conductive powders reached a minimum value 1.5×10³Î©Â·cm.Fluorine-doped tin oxide nanoparticles have been successfully synthesized by precipitation method, the different doped content of fluorine ions kept tin oxide in the phase of tetragonal cassiterite, but the lattice parameters changed obviously. FSB composite powders show potential application in the field of the antistatic coating.The composite coatings have been prepared to use the SSB powders as fillers, the coating can be sprayed or brushed all kinds of surface because of fluidity. When the content of SSB Filler was 20-45%, the resistivity of conductive coating can be adjusted. The surface of coating is smooth, hard wearing and shock resistance. The network structure and dispersity is the key of the good conductivity for conductive coating.