Electrical surface charge and potential of hematite/yttrium oxide core–shell colloidal particles
Electrical surface charge and potential of hematite/yttrium oxide core–shell colloidal particles
复制标题
赤铁矿/氧化钇核壳胶体颗粒的表面电荷和电位
DOI：
10.1007/s003960100578
复制
发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Ángel V. Delgado
中科院分区：
文献类型：
--
作者：
R. Plaza;F. González‐Caballero;Ángel V. Delgado
合成由具有不同组成的核和壳组成的复合胶体颗粒的兴趣源于这样一个事实，即这种颗粒可用于两个核的性质(例如，尺寸和形状均一、易于大量制备、磁性等)的工艺中。和外壳(界面特性、孔隙率、化学稳定性等)可能会感兴趣。然而，适用性必须基于对这些特性的适当表征。本工作采用赤铁矿胶体球(α-Fe_2O_3)作为混合粒子的核，其壳层为氧化钇。通过电位滴定表面电荷和电位与pH的关系，比较了水溶液界面的电学性质与纯氧化物的电学性质。结果发现，由于混合粒子的表面电学特性与氧化钇的行为非常相似，所以混合粒子有效地模拟了氧化钇。然而，发现差异可以归因于覆盖范围不完整或漏洞百出，但当进行总体比较时，这种差异意义不大。
Interest in the synthesis of composite colloidal particles consisting of a core and shell with different compositions stems from the fact that such particles can be useful in processes where the properties of both core (e.g., size and shape homogeneity, ease of preparation in large amounts, magnetic characteristics, etc.) and shell (interfacial properties, porosity, chemical stability, etc.) might be of interest. However, the applicability must be based on a proper characterization of those properties. In this work, colloidal spheres of hematite (α-Fe2O3) were used as nuclei of mixed particles where the shell is yttrium oxide. The electrical properties of the aqueous interface are compared to those of the pure oxides by means of potentiometric titration of their surface charge and potential against pH, as a function of indifferent electrolyte concentration. It is found that the mixed particles efficiently mimic yttrium oxide, since the behavior of their surface electrical characteristics closely resembles that of the latter compound. Differences are found, however, that can be ascribed to an incomplete or porous coverage, but such divergences are of little significance when an overall comparison is carried out.