Janus Particles as Tunable Emulsion Stabilizers

奖励：1067501 PI：Kretzschmar该项目的科学目标是使用具有明确表面组成的Janus颗粒，探索异质表面功能对乳液形成和稳定性的影响。乳液在从化妆品到石油化工的工业过程中无处不在，并且对乳液行为的基本理解一直是超过世纪的研究主题。传统的乳化方法应用分子两亲物来稳定油-水界面。类似地，均质颗粒能够吸附到油-水界面以稳定乳液液滴。然而，在许多工业和自然系统中，吸附颗粒的形状或表面化学性质并不均匀，虽然许多理论研究已经预测了表面各向异性颗粒的行为，但很少有实验来量化界面上的不均匀性的影响。首先，使用均相和非均相颗粒检查乳液的聚结。其次，界面结构和流变性的均匀颗粒稳定的表面进行了探讨，侧重于作为粒径和浓度的函数的界面性质的量化。第三，探讨了Janus粒子稳定的表面的界面结构和流变性，重点讨论了界面有序性在表面力学中的作用。两者合计，这些研究使我们能够了解基本方面的表面不均匀性对乳液稳定性的影响和工程师优化系统稳定多相systems.Intellectual优点：该研究的一个主要目标是推进空间异质表面化学的微米级颗粒对乳液稳定的影响的理解。该项目的结果可能会影响广泛的行业，包括原油勘探和分离过程，水净化和下一代制药/个人护理产品。在非对称粒子表面改性、乳液制备、界面性质表征等方面具有丰富的研究经验。 此外，PI可以使用（i）表面表征仪器，如扫描电子和原子力显微镜，（ii）乳液，流变学和稳定性设备，以及（iii）表面可视化工具。更广泛的影响：乳液和基于乳液的工艺在工业中的重要性怎么强调都不过分。从高中到研究生水平的一系列学生都接受了乳化技术基础和应用方面的培训。此外，国际部分使CCNY学生在当地和国外（哥伦比亚，英国和瑞典）的培训。CCNY的学生通常来自不同的背景，PI在培养具有广泛背景的学生骨干方面有着悠久的历史。CCNY是公认的少数民族服务机构，为西班牙裔（36%），非洲裔美国人（30%），亚洲（23%）和白色（11%）学生的多元化本科生群体提供服务。此外，个别辅导将为女性和少数民族学生在职业生涯早期提供辅导网络。研究结果将通过期刊出版物，会议和网站广泛传播，并将用于为高中和本科生开发实践经验。

Award:1067501PI: Kretzschmar The scientific goal of this project is to explore the effect of heterogeneous surface functionality on emulsion formation and stability using Janus particles with well-defined surface compositions. Emulsions are ubiquitous in industrial processes, ranging from cosmetics to petrochemicals, and the fundamental understanding of emulsion behavior has been the subject of over a century of research. Traditional emulsification processes apply molecular amphiphiles to stabilize the oil-water interface. Similarly, homogenous particles are capable of adsorbing to oil-water interfaces to stabilize emulsion droplets. Yet in many industrial and natural systems, the adsorbing particles are not homogenous in shape or surface chemistry, and, while a number of theoretical studies have predicted the behavior of surface anisotropic particles, few experiments have been conducted to quantify the influence of heterogeneities on the interface.The research is carried out in three parallel steps. First, the coalescence of emulsions is examined, using both homogenous and heterogeneous particles. Second, interfacial structure and rheology of surfaces stabilized by homogeneous particles is probed, focusing on the quantification of interfacial properties as a function of particle size and concentration. And third, interfacial structure and rheology of surfaces stabilized by Janus particles are probed, focusing on the role of interfacial order in the mechanics of the surface. Taken together, these studies allow us to understand fundamental aspects of the effect of surface heterogeneities on emulsion stability and engineer optimized systems for stabilizing multiphase systems.Intellectual Merit: A major goal of the research is to advance the understanding of the effect of spatially heterogenous surface chemistry of micron-sized particles on emulsion stabilization. The results of this project are likely to impact a wide range of industries, including crude oil exploration and separation processes, water purification, and next-generation pharmaceutical/personal care products. The PIs have research experience in asymmetric particle surface modification, emulsion preparation, and characterization of interfacial properties. Further, the PIs have access to (i) surface characterization instruments such as scanning electron and atomic force microscopy, (ii) emulsion, rheology, and stability equipment, and (iii) surface visualization tools. Broader Impacts: The importance of emulsions and emulsion-based processes in industry cannot be overstated. A range of students from the high school to the graduate level are trained in both the fundamental and the applied aspects of emulsion technology. Moreover, an international component enables the training of CCNY students locally and abroad (Colombia, England, and Sweden). CCNY students typically come from a diverse background, and the PIs have a long history of training a cadre of students with wide ranging backgrounds. CCNY is a recognized minority serving institution, which serves a diverse undergraduate student body of Hispanic (36%), African American (30%), Asian (23%), and White (11%) students. Further, individual mentoring will provide female and minority students with a mentoring network early on in their careers. Research findings will be broadly disseminated using journal publications, conferences, and websites and will be used to develop hands-on experiences for high school and undergraduate students.