| Pure BaTiO3 powders were prepared by sol-gel method. The BaTiO3 powders were modified by rare earth elements,such as La,Pr,Nd,Sm,Gd and Er through doping, gaseous penetration and doping- penetration to increase their conductivity. The result showed that all of rare earth can decrease the resistivity of BaTiO3 powders. The effect for decreasing resistivity best was Sm, and then was Pr, La, Er, Nd and Gd. During 3 doping methods, doping- penetration was best. Doping and penetration can decrease the resistivity of BaTiO3 powders. When BaTiO3 powders were both doped and penetrated, the resistivity of BaTiO3 powders were lowest. The resistivity of BaTiO3 powders doped, penetrated and doping- penetrated can decrease from 4.3×109Ω·m to 4.32×105Ω·m, 4.34×104Ω·m and 35.7Ω·m. Through XRD, SEM and FTIR analysis, it can be seen that rare earth elements were on the grain boundary of BaTiO3 after doping. Rare earth elements entered the lattice of the BaTiO3 powders during the penetration process and instead the vacancy of Ti4+. Rare earth elements moved easier than Ti4+ in octahedron. This caused the conductivity decreased.The conductive coatings were prepared using doping-penetrated BaTiO3 powders as conductive additives which were insteaded of traditional additives. The composition and prepared method were founded. The influence of curing agent, dispersant and thinner on resistance and applied quality of the conductive coatings was studied. The conductive coating was composed by epoxy resin 10g, curing agent 13% BaTiO3 powders 5%, dispersant 4%, thinner 4ml/g. The mass of BaTiO3 powders was less than traditional additives. It was cheaper to use. Through FTIR and SEM analysis, BaTiO3 powders were dispersed by dispersant. It made the layer of coating neatly. The parameter of conductive coating was as following: surface conductivity 1.82×1010?, dry time 6h, dry content 94%, rigidity 4.19, viscosity 255s, adhesive force 3, and flexility 2. It can be used to reduce static electricity. |
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