Marangoni Transport Synergism in Mixed Surfactant Systems

混合表面活性剂体系中的马兰戈尼传输协同作用

• 批准号: 1705432
• 负责人: Robert Tilton
• 金额: $ 35.31万
• 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: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1705432&HistoricalAwards=false
• 关键词: Marangoni; Transport; Synergism; Mixed; Surfactant

Surfactants are compounds that lower the surface tension between two phases (for example, oil and water) and are important for a range of complex fluid products, such as laundry detergents, flooding fluids for enhanced oil recovery, and many food, pharmaceutical and consumer products. Fluid flows driven by gradients in surface tension are called "Marangoni flows" and have been well-studied in systems containing a single surfactant. However, industrially important products typically contain mixtures of surfactants. This research project considers how surfactant mixtures may produce strong cooperative or synergistic effects on these Marangoni flows. Experiments to measure these flows and the effects of the surfactants on the interfaces are being performed and compared to theories modified for these multi-component systems. While building on existing knowledge and methods, this research expands into fundamentally interesting and commercially important areas. Understanding the interactions between surfactants is a potentially powerful aid to product formulation across a host of industries. STEM human resource infrastructure is benefitting from the research training of graduate and undergraduate students. Additionally, middle school students are being mentored through the Carnegie Mellon University Physics Concepts Outreach Program in a project in which student-designed experiments reveal interfacial engineering concepts underlying liquid commercial product formulations.Marangoni synergism is the creation of stronger Marangoni transport in the presence of two surfactants than is obtained from either of the two on their own, at the same interfacial tension. This synergism results from the coupled effects of thermodynamics, diffusion, flow conditions, and kinetic rate constants on Marangoni transport. This research project demonstrates this synergism and identifies the conditions that produce it. Experiments are focusing on two-component surfactants in aqueous solutions flowing past a pure oil layer and single-surfactant aqueous solutions flowing past a surfactant-containing oil film. Transient interfacial velocities are being measured as the bulk composition is changed to drive the system out of equilibrium. These transport experiments are being complemented by equilibrium interfacial tension measurements and theoretical transport modeling to identify the influence of dynamic parameters on surfactant compositions that yield Marangoni synergism. The knowledge generated by this research fills a significant knowledge gap in the literature and enables new interfacial approaches for complex fluid formulation.

表面活性剂是一种降低两相（例如油和水）之间表面张力的化合物，对于一系列复杂的流体产品非常重要，例如洗衣剂、提高采收率的驱油液以及许多食品、制药和消费品。由表面张力梯度驱动的流体流动被称为“马兰戈尼流动”，在含有单一表面活性剂的体系中已经得到了很好的研究。然而，工业上重要的产品通常含有表面活性剂的混合物。该研究项目考虑了表面活性剂混合物如何对这些马兰戈尼流产生强大的协同或协同效应。测量这些流动和表面活性剂对界面的影响的实验正在进行，并与针对这些多组分体系修改的理论进行了比较。在现有知识和方法的基础上，本研究扩展到基本有趣和商业上重要的领域。了解表面活性剂之间的相互作用对许多行业的产品配方有潜在的强大帮助。STEM人力资源基础设施受益于研究生和本科生的研究培训。此外，中学生还通过卡耐基梅隆大学物理概念拓展项目接受指导，在该项目中，学生设计的实验揭示了液体商业产品配方背后的界面工程概念。在相同的界面张力下，两种表面活性剂的协同作用比单独使用两种表面活性剂产生更强的马兰戈尼运输。这种协同效应是热力学、扩散、流动条件和动力学速率常数对马兰戈尼输运的耦合效应。本研究项目证明了这种协同作用，并确定了产生这种协同作用的条件。实验主要集中在流过纯油层的双组分表面活性剂水溶液和流过含表面活性剂的油膜的单组分表面活性剂水溶液。当改变体成分使体系失去平衡时，测量的是瞬态界面速度。这些输运实验正在通过平衡界面张力测量和理论输运模型加以补充，以确定动态参数对产生Marangoni协同作用的表面活性剂组成的影响。本研究产生的知识填补了文献中重要的知识空白，并为复杂流体配方提供了新的界面方法。

项目成果

Interfacial dilatational rheology as a bridge to connect amphiphilic heterografted bottlebrush copolymer architecture to emulsifying efficiency

界面膨胀流变学作为连接两亲异质接枝瓶刷共聚物结构与乳化效率的桥梁

• DOI: 10.1016/j.jcis.2020.07.063
• 发表时间: 2021
• 期刊: Journal of Colloid and Interface Science
• 影响因子: 9.9
• 作者: Hsieh, Tsung-Lin;Martinez, Michael R.;Garoff, Stephen;Matyjaszewski, Krzysztof;Tilton, Robert D.
• 通讯作者: Tilton, Robert D.

pH-Dependent Interfacial Tension and Dilatational Modulus Synergism of Oil-Soluble Fatty Acid and Water-Soluble Cationic Surfactants at the Oil/Water Interface

• DOI: 10.1021/acs.langmuir.1c01889
• 发表时间: 2021-09-23
• 期刊: LANGMUIR
• 影响因子: 3.9
• 作者: Hsieh, Tsung-Lin;Law, Stephen;Tilton, Robert D.
• 通讯作者: Tilton, Robert D.