Nanoparticles superficial density of charge in electric double-layered magnetic fluid: A conductimetric and potentiometric approach
Nanoparticles superficial density of charge in electric double-layered magnetic fluid: A conductimetric and potentiometric approach
复制标题
DOI：
10.1007/s101890170025
复制
发表时间：
2001-09-01
影响因子：
1.8
通讯作者：
Depeyrot, J
中科院分区：
文献类型：
--
作者：
Campos, AFC;Tourinho, FA;Depeyrot, J
我们分析电位和电导测量同时进行的双电层磁流体的基础上钴铁氧体纳米粒子，以获得颗粒表面电荷密度的pH依赖性。我们提出了一种机制的粒子表面的充电。该模型将铁磁流体溶液视为强二元酸和弱二元酸的混合物。我们展示了如何一个精确的分析处理，涉及粒子表面和散装溶液之间的质子转移允许建设的带电表面站点的形态图。电荷表观密度的饱和值等于0.326 +/-0.065Cm（-2）。
We analyze potentiometric and conductimetric measurements simultaneously performed on Electric Double-Layer Magnetic Fluid based on cobalt ferrite nanoparticles, in order to obtain the pH-dependence of the particle surface charge density. We propose a mechanism for the charging of the particle surface. This model considers the ferrofluid solution as a mixture of strong and weak diprotic acids. We show how an exact analytical treatment involving proton transfer between the particle surface and the bulk solution allows the construction of a speciation diagram of the charged superficial sites. The saturation value of the superficial density of charge is found to be equal to 0.326 +/- 0.065 C m(-2).