Anand Sushant, Galavan Vincent, Mulik Mahesh Uttamrao
Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 West Taylor St., Chicago, IL, 60607, USA.
Department of Nuclear Science & Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA.
Adv Sci (Weinh). 2024 Apr;11(15):e2307443. doi: 10.1002/advs.202307443. Epub 2024 Feb 14.
Emulsions are widely used in many industrial applications, and the development of efficient techniques for synthesizing them is a subject of ongoing research. Vapor condensation is a promising method for energy-efficient, high-throughput production of monodisperse nanoscale emulsions. However, previous studies using this technique are limited to producing small volumes of water-in-oil dispersions. In this work, a new method for the continuous synthesis of nanoscale emulsions (water-in-oil and oil-in-water) is presented by condensing vapor on free-flowing surfactant solutions. The viability of oil vaporization and condensation is demonstrated under mild heating/cooling using diverse esters, terpenes, aromatic hydrocarbons, and alkanes. By systematically investigating water vapor and oil vapor condensation dynamics on bulk liquid-surfactant solutions, a rich diversity of outcomes, including floating films, nanoscale drops, and hexagonally packed microdrops is uncovered. It is demonstrated that surfactant concentration impacts oil spreading, self-emulsification, and such behavior can aid in the emulsification of condensed oil drops. This work represents a critical step toward advancing the vapor condensation method's applications for emulsions and colloidal systems, with broad implications for various fields and the development of new emulsion-based products and industrial processes.
乳液在许多工业应用中被广泛使用，开发高效的乳液合成技术是当前研究的一个课题。蒸汽冷凝是一种有前景的方法，可用于高效、高通量地生产单分散纳米级乳液。然而，以前使用该技术的研究仅限于生产少量的油包水型分散体。在这项工作中，通过在自由流动的表面活性剂溶液上冷凝蒸汽，提出了一种连续合成纳米级乳液（油包水型和水包油型）的新方法。在温和的加热/冷却条件下，使用多种酯类、萜类、芳烃和烷烃证明了油汽化和冷凝的可行性。通过系统地研究大量液体-表面活性剂溶液上的水蒸气和油蒸气冷凝动力学，发现了丰富多样的结果，包括漂浮膜、纳米级液滴和六边形排列的微滴。结果表明，表面活性剂浓度会影响油的铺展、自乳化，这种行为有助于冷凝油滴的乳化。这项工作是推进蒸汽冷凝法在乳液和胶体系统中的应用的关键一步，对各个领域以及新型乳液基产品和工业工艺的开发具有广泛的意义。
