In situ analysis of electropolymerization of aniline by combined electrochemistry and surface plasmon resonance
In situ analysis of electropolymerization of aniline by combined electrochemistry and surface plasmon resonance
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DOI：
10.1021/la0155303
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发表时间：
2002-03-05
期刊：
影响因子：
3.9
通讯作者：
Dong, SJ
中科院分区：
文献类型：
--
作者：
Kang, XF;Jin, YD;Dong, SJ
用电化学和表面等离子体共振(SPR)相结合的方法研究了聚苯胺(PAN)在金电极表面的电位循环过程。揭示了PAN薄膜的电势调制表面等离子体共振特性。由于PAN薄膜电导率的转变导致介电常数虚部的变化，PAN氧化态和还原态之间的电势转换会导致SPR响应的较大变化。PAN薄膜在电势循环过程中的氧化还原转变对SPR测量是非常有利的。采用SPR角扫描(R-theta)和固定角度反射率随时间变化(R-t)两种SPR测量模式，研究了PAN薄膜的生长过程。在循环电位扫描的每个阴极极限处记录的共振极小值的角度移动允许对薄膜生长的明确测量。在循环电位扫描过程中，由于PAN薄膜的氧化还原开关，R-t曲线被沿电位斜坡的方向反复调制，并且电位调制反射率变化的幅度与循环次数有很好的相关性。R-t曲线的时间差使得连续监测薄膜生长过程成为可能。这些结果表明，该组合技术适用于研究导电聚合物的电聚合过程。
The combination of electrochemistry with surface plasmon resonance (SPR) has been used to characterize the growth of polyaniline (PAn) on a gold electrode surface during potential cycling. Potential-modulated SPR characteristics of the PAn film were also revealed. The potential switch between the oxidized and reduced states of PAn can lead to a large change of SPR response due to the variation in the imaginary part of the dielectric constant of PAn film resulting from the transition of the film in conductivity. The redox transition of the PAn film during potential cycling is very profitable to the SPR measurements. Two modes of SPR measurement, SPR angular scan (R-theta) and the time evolution of the reflectivity change at a fixed angle (R-t), were displayed to study the growth process of the PAn film. The angle shift of the resonance minimum recorded at each cathodic limit of cyclic potential scanning allows for the unambiguous measurement of the film growth. During cyclic potential scanning, the R-t curve was repeatedly modulated with the direction of the potential ramp as a result of the redox switch of the PAn film, and the amplitude of potential-modulated reflectivity change was well correlated with the cyclic number. The time differential of the R-t curve permits continuous monitoring of the film growth process. These results illustrate that the combined technique is suitable for studying the electropolymerization process of a conducting polymer.