Abstract

Powders of magnetite and its composites have been obtained on the basis of macroporous high-silica glass particles containing different amounts of Fe₃O₄. XRD, XPS, and Raman spectroscopy have been employed to confirm the formation of a magnetite phase in all iron-containing samples. The surface morphology and elemental composition of porous composite particles have been studied by SEM and EDX methods. It has been found that the external surface of porous silica particles is modified to different extents. It has been shown that the position of the isoelectric point (IEP) and the values of the zeta-potentials for the composites coincide in indifferent electrolyte solutions. Two isoelectric points are observed in the pH dependences of the zeta-potential for the composite particles in nickel chloride solutions. In dilute solutions containing specifically adsorbed nickel ions and at pH below pH_IEP-2, the electrokinetic properties of the composite particles are primarily affected by magnetite phase content in a composite powder and, at rather high concentrations of Ni²⁺ ions, by their specificity with respect to oxide surfaces.

中文翻译：

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磁铁矿含量和镍(II)离子特异性对多孔二氧化硅颗粒复合材料电动性能的影响

摘要

_{以含不同量Fe 3} O ₄的大孔高硅玻璃颗粒为基础，制得磁铁矿及其复合材料粉体。。XRD、XPS 和拉曼光谱已用于确认所有含铁样品中磁铁矿相的形成。通过SEM和EDX方法研究了多孔复合颗粒的表面形貌和元素组成。已经发现多孔二氧化硅颗粒的外表面被不同程度地改性。研究表明，在不同的电解质溶液中，复合材料的等电点 (IEP) 位置和 zeta 电位值是一致的。在氯化镍溶液中复合颗粒的 zeta 电位的 pH 依赖性中观察到两个等电点。在含有特定吸附镍离子的稀溶液中且 pH 值低于_IEP-2，复合颗粒的动电性能主要受复合粉末中磁铁矿相含量的影响，并且在相当高浓度的 Ni ²⁺离子下，受其相对于氧化物表面的特异性的影响。