温度/剪切场对SWCNTs/EP分散体系导电性能的影响

Influnce of temperature and shearing field on conductive property of SWCNTs/EP disperse system

以单壁碳纳米管(SWCNTs)为填充剂制备了环氧树脂(EP)液态复合导电体系。对不同温度和剪切场下SWCNTs/EP分散体系的导电性能进行了测试。结果发现:SWCNTs含量增加,分散体系黏度和电导率提高,当SWCNTs含量为0.5%时(vol,下同),体系导电性能的变化趋于平缓。温度升高,体系的导电性能提高,在40℃至95℃之间,体系的电导逾渗值从0.31%降低到0.15%,电导率由2.4×10-7S/m升高至7.0×10-2S/m,上升5个数量级。50℃下剪切速率从60r/min增大到300r/min,SWCNTs含量为0.025%的体系电导率略有增加(由2.0×10-5 S/m升高到3.0×10-5S/m),超过0.05%后,体系电导率随剪切时间的延长先减小后增大。此外,剪切场导致体系逾渗值增大,电导率降低。

The composite conductive colloid was prepared via ultrasonic mixing used by single-walled carbon nano- tubes（SWCNTs） and epoxy resin（EP）. The influence of SWCNTs/EP disperse systems on conductive property was investi- gated under the action of temperature and shearing field. The results showed that the viscosity and conductivity of SWC- NTs/EP disperse systems were increased with increasing the content of SWCNTs. whereas when the content exceeded 0. 5 vol%, the conductivity of the systems did not increase any more. The percolation value of the systems reduced from 0. 31 vol% to 0. 15 vol%. The conductivity increased five orders of magnitude from 2. 4× 10^-7 S/m to 7. 0× 10^-2S/m with tem- peratures rising from 40℃ to 95℃. The conductivity of the 0. 025 vol % content of SWCNTs system was increased just from 2.0×10^-5 S/m to 3.0× 10 ^-5S/m under shearing rates from 60r/min to 300r/min at 50℃. When the content of SWC- NTs in the dispersion system was more than 0. 05 vol%, the conductivity of system would be increased at first and then de- scend with shearing time at 60r/min, 150r/min, 250r/min and 300r/min.In addition, the shear field leaded to the percolation value increased and the conductivity reduced.