甲苯胺蓝在SDS胶束中的电化学行为研究  

Electrochemistry behaviors of Toluidine Blue in the presence of SDS micelles

作　　者：马艳蓉[1] 高作宁[1] 

机构地区：[1]宁夏大学能源化工重点实验室化学化工学院,宁夏银川750021

出　　处：《化学研究与应用》2006年第8期912-916,共5页Chemical Research and Application

基　　金：宁夏自然科学基金(E1001)项目资助;宁夏高等学校科学研究基金(210)项目资助

摘　　要：在玻碳电极上研究了甲苯胺蓝(TB)及其在SDS胶束中的电化学行为,并与其直接电化学行为进行了比较。研究结果表明,TB在玻碳电极上的电极反应为2电子可逆氧化还原反应过程。通过介质pH对TB电极反应过程影响的研究,确定在pH<4.2,4.2<pH<5.9及pH>5.9时,参与电极过程的质子数分别为3,2和1,同时给出了TB解离常数K1与K2分别为1.68×10-5和1.93×10-6。在浓度分别为0.05mol.dm-3和0.1mol.dm-3PBS缓冲溶液中,TB在SDS浓度接近其临界胶束浓度(CMC)附近时,其还原峰电流(Ipc)和还原峰电位(Epc)随SDS浓度的增加而降低和负移。在大于CMC浓度时,其还原峰电流(Ipc)和还原峰电位(Epc)随SDS浓度的增加而上升和正移,之后出现了一个平台段。同时还测定了TB及其在胶束体系中的扩散系数D及电极反应速率常数Kf,并对SDS胶束对TB电化学行为的影响因素给出了合理的理论解释。The electrochemical behaviors and the kinetics parameters of Toluidine Blue （TB） were studied at glassy carbon electrode in the absence and in the presence of SDS micelles aqueous solutions. The experimental results showed that two electrons took part in the reversible redox of TB at glass carbon electrode. The effect of pH on the electrode reaction process was investigated and the proton number in the electrode reaction process is 3,2 and 1 in the pH ranges of 1 -4. 2,4. 2 -5.9 and 5.9 - 12,respectively. The dissociation constants of TB were determined as K1 = 1.68 × 10 ^-5 and K2 = 1.93 × 10^-6. The reductive peak current （Ipc） and peak potential （Epc） of TB decreased and shifted negatively at two different concentrations of PBS,0. 05 and 0. 1mol·dm^-3 ,while the concentration of sodium decylsulfate （SDS） approachs the critical micelle concentration （CMC）. Ipc and Epc increased and shifted positively when the concentration of SDS above the CMC, subsequently they reached a plateau. The kinetics parameters, diffusion coefficient D and electrode reaction rate constant kf of TB were obtained and the influencing factors of SDS micelle on the electrochemical behaviors of TB were elucidated in details as well.

关 键 词：玻碳电极 甲苯胺蓝 SDS胶束 电化学行为 

分 类 号：O647[理学—物理化学]