Department of Chemical Engineering, University of Washington, Seattle, WA, USA.
Department of Chemical Engineering, University of Washington, Seattle, WA, USA; Department of Bioengineering, University of Washington, Seattle, WA, USA.
J Colloid Interface Sci. 2019 Feb 15;536:281-290. doi: 10.1016/j.jcis.2018.10.047. Epub 2018 Oct 19.
Sonication is one of the most commonly used methods to synthesize Pickering emulsions. Yet, the process of emulsion sonication is rarely characterized in detail and acoustic conditions are largely determined by experimenter's personal experience. In this study, the role of sonication in the formation of Pickering emulsions from amphiphilic gold nanoparticles was investigated using a new sample environment combining ultrasound delivery with ultra-small-angle X-ray scattering (USAXS) measurements. The detection of acoustic cavitation and the simultaneous analysis of structural data via USAXS demonstrated direct correlation between Pickering emulsion formation and cavitation events. There was no evidence of spontaneous adsorption of particles onto the oil-water interface without ultrasound, which suggests the presence of a stabilizing force. Acoustically detected cavitation events could originate in the bulk solvent and/or inside the emulsion droplets. These events helped overcome energy barriers to induce particle adsorption.
超声处理是合成 Pickering 乳液最常用的方法之一。然而，乳液超声处理的过程很少被详细描述，并且声学条件在很大程度上取决于实验者的个人经验。在这项研究中，使用一种新的样品环境，将超声传递与超小角 X 射线散射（USAXS）测量相结合，研究了超声处理在由两亲性金纳米粒子形成 Pickering 乳液中的作用。通过 USAXS 检测声空化和同时分析结构数据，证明了 Pickering 乳液形成与空化事件之间存在直接相关性。在没有超声的情况下，没有观察到粒子自发吸附到油水界面上的现象，这表明存在稳定力。通过声学检测到的空化事件可能起源于溶剂本体和/或乳液液滴内部。这些事件有助于克服能量障碍，诱导粒子吸附。
