乳液聚合中聚苯胺膜形成的动力学研究

以(NH4)2S2O8(APS)为氧化剂,十二烷基苯磺酸(DBSA)同时为乳化剂和掺杂剂,采用乳液聚合方法制备聚苯胺膜(PANIfilm),用石英晶体微天平(QCM)实时监测聚苯胺膜的形成过程,并对其动力学过程进行研究.结果表明,聚苯胺成膜反应对APS是0.5级,对苯胺是1级,聚苯胺膜增长速率随温度的升高而增加,而聚苯胺膜的最终沉积量却减小,表观活化能Ea=41.15kJ/mol,与均相溶液聚合成膜法的结果相近;随着DBSA浓度的增加,聚苯胺膜增长速率减小,而最终的沉积量增大.

KINETICS OF POLYANILINE FILM FORMATION BY EMULSION POLYMERIZATION

Ammonium persulfate (APS) was used as oxidant,and dodecylbenzoyl sulfonic acid (DBSA) was used as both emulsifier and dopant to prepare polyaniline (PANI) in emulsion polymerization of anitine.The formation of PANI films on the gold electrode was monitored by quartz crystal microbalance (QCM).Kinetic process of this reaction was investigated by exploring the effect concentrations of aniline,APS and DBSA as well as temperature on the polymerization.The results indicate that the reaction exhibited half-order characteristics with respect to APS and first-order characteristics to aniline.The growth rate of PANI film and the maximum value of the deposited PANI film on gold electrode increased with the rise of APS and aniline concentrations.At the concentration of DBSA among 0.01～0.027 mol/L,the growth rate of PANI film decreased with the rise of DBSA,and the ultimate value of the deposited PANI film on gold electrode increased with the rise of DBSA.In addition,the growth rate of PANI film increased with the rise of temperature from 15℃ to 35℃,but the ultimate deposition amount decreased with the rise of temperature.The activation energy of this reaction is 41.15 kJ/mol calculated according to the Arrhenius equation,which is similar to that of PANI films prepared by homogeneous solution method.