Polyacrylate-based conductive coatings were prepared from polyacrylate emulsion as matrix and carbon black (CB) whose surface was treated with titanate coupling agent as conducting particles.One kind of organic crysta...Polyacrylate-based conductive coatings were prepared from polyacrylate emulsion as matrix and carbon black (CB) whose surface was treated with titanate coupling agent as conducting particles.One kind of organic crystal was added to study its effects on the electrical conductivity and PTC(positive temperature coefficient)effect of the conductive coatings.Experimental results show that the coatings containing only polyacrylate emulsion and CB exhibit an excellent electrical conductivity but bad PTC effect,and when organic crystal is added,PTC effect is characterized and can increase by 2 orders of magtitude.The critical transformation temperature of polyacrylate emulsion/CB PTC composites is decided by melting point of organic crystals.展开更多
The Daniels’ barium vacancy layer model of semiconducting BaTiO3 ceramics is analyzed.A grain boundary barrier model with both acceptor states of grain boundary and barium vacancy diffusion layers for the transition ...The Daniels’ barium vacancy layer model of semiconducting BaTiO3 ceramics is analyzed.A grain boundary barrier model with both acceptor states of grain boundary and barium vacancy diffusion layers for the transition from PTC effect to grain boundary barrier layer (GBBL) capacitor is proposed.The proposed model solves the problem occurring in Daniels’ model and makes it possible to calculate physical properties of semiconducting BaTiO3 ceramics and relevant devices.展开更多
Polymer positive temperature coefficient(PTC) material comprising conductive particles, e.g. carbon black(CB), dispersed in polymer matrix is suitable for use as electrical devices such as circuit overcurrent protecti...Polymer positive temperature coefficient(PTC) material comprising conductive particles, e.g. carbon black(CB), dispersed in polymer matrix is suitable for use as electrical devices such as circuit overcurrent protection device, self-regulation heaters, sensors, etc.. In this paper, the PTC effect of carbon black filled polyethylene and ethylene-propylene-diene terpolymer blends was studied. Effects of raw material ratio and type of carbon black were investigated. The distribution of CB in polymer matrix and the function of crystallites on PTC effect were discussed.展开更多
文摘Polyacrylate-based conductive coatings were prepared from polyacrylate emulsion as matrix and carbon black (CB) whose surface was treated with titanate coupling agent as conducting particles.One kind of organic crystal was added to study its effects on the electrical conductivity and PTC(positive temperature coefficient)effect of the conductive coatings.Experimental results show that the coatings containing only polyacrylate emulsion and CB exhibit an excellent electrical conductivity but bad PTC effect,and when organic crystal is added,PTC effect is characterized and can increase by 2 orders of magtitude.The critical transformation temperature of polyacrylate emulsion/CB PTC composites is decided by melting point of organic crystals.
文摘The Daniels’ barium vacancy layer model of semiconducting BaTiO3 ceramics is analyzed.A grain boundary barrier model with both acceptor states of grain boundary and barium vacancy diffusion layers for the transition from PTC effect to grain boundary barrier layer (GBBL) capacitor is proposed.The proposed model solves the problem occurring in Daniels’ model and makes it possible to calculate physical properties of semiconducting BaTiO3 ceramics and relevant devices.
文摘Polymer positive temperature coefficient(PTC) material comprising conductive particles, e.g. carbon black(CB), dispersed in polymer matrix is suitable for use as electrical devices such as circuit overcurrent protection device, self-regulation heaters, sensors, etc.. In this paper, the PTC effect of carbon black filled polyethylene and ethylene-propylene-diene terpolymer blends was studied. Effects of raw material ratio and type of carbon black were investigated. The distribution of CB in polymer matrix and the function of crystallites on PTC effect were discussed.
