SiO₂ nanoparticles and surfactant sodium bis-(2-ethylhexyl) sulfosuccinate (AOT) are widely used in modern nanochemistry to obtain novel materials in various processes. However, only a few publications are devoted to investigation of the stabilization mechanisms of SiO₂ dispersions in aqueous AOT solutions. In this work, the surface electrical properties of SiO₂ nanoparticles and the nature of free charges in aqueous solutions were studied over a wide range of AOT concentrations (2.5∙10^–6 ÷ 2.5∙10^–2 M). The absolute value of ζ-potential of the particles increased from –42 to –58 mV, while the hydrodynamic radius remained constant and equal to ca. 40 nm. Calculations within the Derjaguin–Landau–Verwey–Overbeek (DLVO) theory revealed that stability of hydrosols is caused by the electrostatic component of disjoining pressure. Due to the repulsion of similarly charged nanoparticles and glass substrate, the hydrosols formed coffee rings during evaporation of sessile droplets. The results obtained make it possible to control surface properties of the particles, thus opening the possibility to use SiO₂-AOT hydrosols for the formation of various 2D materials and substrates in photonics, catalysis and biosensorics.

SiO ₂纳米颗粒和表面活性剂双-（2-乙基己基）磺基琥珀酸钠（AOT）广泛用于现代纳米化学，以通过各种工艺获得新材料。然而，只有少数出版物致力于研究 SiO ₂分散体在 AOT 水溶液中的稳定机制。在这项工作中，SiO ₂纳米粒子的表面电学性质和水溶液中自由电荷的性质在很宽的 AOT 浓度范围内进行了研究 (2.5∙10 ^–6  ÷ 2.5∙10 ^–2米）。粒子的 ζ 电位绝对值从 –42 mV 增加到 –58 mV，而流体动力学半径保持恒定并等于约。40 纳米。Derjaguin-Landau-Verwey-Overbeek (DLVO) 理论中的计算表明，水溶胶的稳定性是由分离压力的静电分量引起的。由于类似带电的纳米颗粒和玻璃基材的排斥，水溶胶在固着液滴的蒸发过程中形成了咖啡环。所获得的结果可以控制颗粒的表面性质，从而开启了使用 SiO ₂ -AOT 水溶胶形成光子学、催化和生物传感器中各种二维材料和基材的可能性。