CB／PBMA复合材料在有机蒸汽中的电阻响应与吸附行为

Electrical Responses and Adsorption of Conductive CB/PBMA Composites Against Organic Solvent Vapors

研究了炭黑/聚甲基丙烯酸丁酯(CB/PBMA)复合材料在有机蒸汽中的电阻响应和吸附行为。结果表明,在较大的有机蒸汽分压范围内(p/p°=0～0.16),CB/PBMA导电复合材料在丙酮和氯仿蒸汽中的电阻响应程度的对数与蒸汽分压之间存在良好的线性关系,而且该复合材料的电阻响应程度随有机蒸汽分压的变化曲线与其吸附等温线吻合,而与炭黑的吸附等温线差别较大。前者的吸附曲线符合Ⅲ型吸附,因为复合材料表面没有微孔只有大孔,而后者的吸附曲线是典型的Ⅱ型吸附,这是由于炭黑表面有丰富的微孔和中孔。

Electrical resistance responses and adsorption of carbon black filled poly（butyl methacrylate） （CB/PBMA） composites synthesized by in-situ polymerization to organic vapors were investigated. The experimental results indicate that the logarithmic electrical responsivity, lg（△Rmax/R0）, of the composites in acetone or chloroform vapor varies linearly with vapor pressure in a relatively wide range （p/pn=0-0.16）. The curve of the composites＇ electrical responsivity versus vapor pressure is coincident with their equilibrium adsorption curve in organic vapor, but different from that of carbon black. The equilibrium adsorption curve of the composites in organic vapor accords with the third type adsorption model because there are no pores hut large holes in the composites＇ surface, while the equilibrium adsorption curve of carbon black accords with the second type adsorption model due to sufficient micropore and mesopore in the CB particle surface. These findings would help to understand electrical response mechanism of the composites as promising gas-sensing materials.