超声辐射对PVA/CB导电复合材料气敏性能的影响

以聚乙烯醇(PVA)为基体,填充各种类型炭黑导电粒子,制备了导电复合薄膜。研究了超声作用下导电复合薄膜在不同溶剂蒸气中的气敏性能。考察了PVA与炭黑的比例、炭黑种类、超声时间、超声功率等条件对导电薄膜响应性能与响应稳定性的影响,并对这种导电复合薄膜产生气敏响应性的机理作了分析。结果表明,以PVA/乙炔炭黑组成的导电复合薄膜具有较强气敏响应性。当将其置于丙酮、正丁醇、乙醇、水极性溶剂中,电阻急剧提高102~103倍,表现为正蒸气系数效应(PVC);随炭黑含量提高,复合材料薄膜室温电阻下降,对溶剂蒸气的响应强度提高;超声时间、功率对导电粒子分散行为及复合材料的气敏性有影响,随超声时间延长及功率增大,接枝改性效果明显,导电薄膜的响应性及重复稳定性提高。

Influence of Ultrasonic Radiation on Vapor Sensitivity of Conductive PVA/CB Composite Films

A conductive poly(vinyl alcohol)/carbon black(PVA/CB) composite film was prepared by resolution mixing process with the help of ultrasonic technology using PVA as matrix,doped with various conductive carbon black particles.The responsiveness of the PVA grafted carbon black(PVA-g-CB)/PVA composite film to various solvent vapors was studied by sonicating the PVA/CB composite solution,compared with ungrafted carbon black/PVA composite film.The effects of CB content and kinds,ultrasonic time and power on responsive performances and stability of the composite film were investigated,and the responsive mechanism of the composite film to different vapors was also analyzed.The results showed that the PVA/acetylene black conductive composite film presented higher vapor sensitivity,whose resistance rose 10~2~10~3 times rapidly when it was under polar solvents,such as acetone,n-butyl alcohol,ethanol,water etc,and the responsive intensity of the composite film after sonicated was remarkably higher than the composite film filled with ungrafted carbon black.The electric resistance at room temperature decreased and the responsive intensity to different solvent vapors enhanced with CB content increase.The ultra-sonic time and power affected the dispersion behavior of carbon black particles and vapor sensitivity of the composite film.The grafting effect was remarkable and the responsiveness of the sensitive materials was improved with longer sonicating time and power.