Connecting Interfacial Properties to Emulsion Stability for Complex Particle-Laden Interfaces

将复杂颗粒界面的界面特性与乳液稳定性联系起来

• 批准号: 1437864
• 负责人: Lynn Walker
• 金额: $ 35万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1437864&HistoricalAwards=false
• 关键词: Connecting; Interfacial; Properties; Emulsion; Stability

CBET 1437864Emulsions and foams occur in many processes of industrial and biological importance. The food, cosmetic, pharmaceutical, medicinal, polymer, and oil and gas industries routinely process emulsions and foams. One of the key requirements in making useful, long-lived products from emulsions and foams is to guarantee that they are stable by preventing the drops or bubbles from coalescing with each other, which can degrade product quality. This project will use a microtensiometer developed by the investigators to examine the physical and chemical properties of drop and bubble interfaces and determine how those properties influence the coalescence of two drops under carefully controlled conditions. Using the microtensiometer, the investigators will examine the coalescence process while simultaneously acquiring information about the interfacial characteristics of the drops. The influence of emulsifiers that can stabilize emulsions by adsorbing onto drop interfaces and preventing coalescence will be examined. Then, the team will explore the effectiveness of a novel stabilizer consisting of nanoparticles coated with surfactants. The results will provide new tools to scientists and engineers who formulate emulsions and foams and design systems to process them.A microtensiometer will be used to study the interfacial rheology of small drops and bubbles with radii between 50 and 150 micrometers. By monitoring the pressure inside the bubble and the interfacial area, the dynamic surface tension and interfacial elasticity of the interface can be determined. To access conditions where the adsorption of surfactants onto the interface is kinetically limited, the device will be modified by adding a convective flow past the interface. The microtensiometer will then be used to observe the coalescence of two drops or bubbles with identical curvature, composition and history, which will help eliminate ambiguities that occur in other coalescence measurements. The results will be used to ascertain the relationship between interfacial rheology and coalescence. The effects of particle-laden interfaces on coalescence will be characterized using a model system of surfactant-coated nanoparticles that readily adsorb onto interfaces.

CBET 1437864乳液和泡沫出现在许多工业和生物重要性的过程中。 食品、化妆品、制药、医药、聚合物以及石油和天然气工业通常加工乳液和泡沫。 从乳液和泡沫中制造有用的长寿命产品的关键要求之一是通过防止液滴或气泡彼此聚结来确保它们的稳定性，这会降低产品质量。 该项目将使用研究人员开发的微张力计来检查液滴和气泡界面的物理和化学性质，并确定这些性质如何影响两滴在仔细控制条件下的聚结。 使用显微张力计，研究人员将检查聚结过程，同时获得有关液滴界面特性的信息。 乳化剂的影响，可以通过吸附到液滴界面和防止聚结稳定乳液将被检查。 然后，该团队将探索由表面活性剂包覆的纳米颗粒组成的新型稳定剂的有效性。 研究结果将为科学家和工程师提供新的工具，他们可以配制乳液和泡沫，并设计系统来处理它们。微张力计将用于研究半径在50到150微米之间的小滴和气泡的界面流变学。 通过监测气泡内的压力和界面面积，可以确定界面的动态表面张力和界面弹性。 为了获得表面活性剂在界面上的吸附受到动力学限制的条件，将通过添加经过界面的对流来修改装置。 然后，显微张力计将用于观察具有相同曲率、组成和历史的两个液滴或气泡的聚结，这将有助于消除在其他聚结测量中出现的模糊性。 研究结果将用于确定界面流变性和聚结之间的关系。 粒子负载的界面上的聚结的影响，其特征在于使用一个模型系统的表面活性剂涂层的纳米粒子，很容易吸附到界面上。