吸附模式识别方法及其应用

电活性物质在电极上吸附是十分复杂的,无法用一简单模型描述。不同的吸附模型决定不同的吸附电流方程,因此判别电活性物质的吸附行为服从那种模式具有理论和实际意义,目前,吸附等温模式使用较多的主要有Langmuir等温式、Frumkin等温式和Temkin等温式,通常的识别方法是将实验测定得到的覆盖度θ和电活性物质在溶液中的浓度C代入上述模型方程,并逐一插值计算或拟合回归分析求出最接近的那个模式,以确定该物质的吸附方式。但计算与实验结果有一定差异,且工作量很大。最近张正奇等提出的单纯形-偏差图半定量识别法,具有一定使用价值。本文将介绍一种通用的定量、快速的识别吸附模式法。

Adsorption Pattern Recognition and Its Application in Adsorptive Polarographic Wave

In this paper, a adsorption equation, βC=[0/(1-0) ]"exp(g'0), is proposed as a general adsorption pattern recongnition, on which we are able to recognize isotherm of the electroactive species adsorbed on electrode, and to estimate adsorption parameters.It was applied to the inverstigation of the adsorptions of T(4-TMAP)Pand CNAon DME, The results show that the former obeys Langmuir isotherm, the adsorption equation is [θ/(l-θ) ]^0.96=7.76×10⁶×e^-0.240×C, and the latter obeys Frumkin isotherm, the adsorption equation [θ/(l--θ)]^1.03=1.18×10⁵×10^2.220×C, These are consistent with those of literatures.