Ion Adsorption on Modified Electrodes as Determined by Direct Force Measurements under Potentiostatic Control
Ion Adsorption on Modified Electrodes as Determined by Direct Force Measurements under Potentiostatic Control
复制标题
通过恒电位控制下的直接力测量确定改性电极上的离子吸附
DOI：
10.1021/jp500425g
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发表时间：
2014
影响因子：
3.7
通讯作者：
Papastavrou
中科院分区：
文献类型：
--
作者：
Kuznetsov;Papastavrou
离子吸附是一个充电过程，对于许多疏水表面（如气泡、油滴和细胞膜）至关重要。这个过程已经研究了各种技术和不同的吸附机制已经提出了到目前为止。然而，不同的分析方法似乎表明不同类型的离子，特别是羟基或水合氢离子，在疏水表面的吸附。本文采用胶体探针技术，通过直接力测量研究了离子在修饰电极上的吸附。用自组装单分子层（SAM）修饰电极，并通过恒电位仪从外部控制其电位。离子吸附到OH-或CH 3-终止的自组装膜被确定为pH值和背景电解质浓度的函数。在界面处的电荷被发现主要是由于从羟基和水合氢离子的吸附，而背景电解质（KCl）的影响可以忽略不计。对于水合氢离子和氢氧根离子，我们通过一个简单的半定量模型测定的吸附常数，发现氢氧根离子的吸附常数是数量级大于水合氢离子。此外，离子吸附被发现是更明显的疏水表面比亲水性的。
Ion adsorption is a charging process that is of central importance for many hydrophobic surfaces, such as gas bubbles, oil drops, and cell membranes. This process has been studied by various techniques and different adsorption mechanisms have been proposed so far. However, different analytical methods seem to indicate the adsorptions of different types of ions, particularly hydroxyl or hydronium ions, at hydrophobic surfaces. In this work, we studied ion adsorption on modified electrodes by direct force measurements with the colloidal probe technique. The electrodes were modified with a self-assembled monolayer (SAM), and their potential was controlled externally by means of a potentiostat. Ion adsorption onto OH- or CH3-terminated SAMs was determined as a function of pH and background electrolyte concentration. Charge at the interface was found to result primarily from the adsorption of hydroxyl and hydronium ions, whereas the influence of the background electrolyte (KCl) can be neglected. For the hydronium and hydroxyl ions, we determined the adsorption constants by means of a simple semiquantitative model and found that the adsorption constant of hydroxyl ions is orders of magnitude larger than that of hydronium ions. Furthermore, ion adsorption was found to be much more pronounced for hydrophobic surfaces than for hydrophilic ones.
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DOI：
--
发表时间：
2008
期刊：
影响因子：
--
作者：
S. Rentsch
通讯作者：
S. Rentsch
影响因子：
9.9
作者：
Pericet-Camara, R;Papastavrou, G;Borkovec, M
通讯作者：
Borkovec, M
影响因子：
3.9
作者：
Fréchette, J;Vanderlick, TK
通讯作者：
Vanderlick, TK
DOI：
10.1021/la800801v
发表时间：
2008-09-16
期刊：
Langmuir : the ACS journal of surfaces and colloids
影响因子：
--
作者：
White RJ;Phares N;Lubin AA;Xiao Y;Plaxco KW
通讯作者：
Plaxco KW
注意：用于原子力显微镜的二氧化硅颗粒的机械和化学稳定的胶体探针。
DOI：
10.1063/1.4765299
发表时间：
2012
期刊：
The Review of scientific instruments
影响因子：
--
作者：
V. Kuznetsov;G. Papastavrou
通讯作者：
G. Papastavrou