CAREER: Understanding the Interfacial Rheology of Carbon Nanotubes at the Fluid-Fluid Interfaces for Creating Ultra-stable Emulsions and Microcapsules

职业：了解碳纳米管在流体-流体界面处的界面流变学，以创建超稳定的乳液和微胶囊

• 批准号: 1253613
• 负责人: Anson Ma
• 金额: $ 40万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-15 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1253613&HistoricalAwards=false
• 关键词: CAREER; Understanding; Interfacial; Rheology; Carbon

1253613MaIt has been known for more than a century that particles can stabilize emulsions by adsorbing at the fluid-fluid interface and lowering the interfacial energy. Thermodynamics and earlier experimental studies indicate that controlling the particle size and wetability are two key factors to stabilize emulsions. However, the effect of particle shape has remained largely unexplored and unexploited. The hypothesis of this proposal is that particle shape matters and that rod-like and high-aspect-ratio particles will increase the number of particle-particle contacts, leading to the formation of a stronger layer at the interface and consequently more stable emulsions relative to spheres. To examine this hypothesis, carbon nanotubes (CNTs) with high aspect ratio (1000) will be investigated as a model system. The objective is to establish a fundamental understanding of the physics of an interface decorated with CNTs. The microstructure and the interfacial rheology will be carefully examined and further linked to the mechanical integrity and stability of a CNT-laden interface. The intellectual merit of this proposal involves: (1) exploring the complex physics of CNTs at the fluid-fluid interface, and (2) connecting the rheology with interfacial phenomena. Broader Impact: Exploiting the particle shape could be the missing key to unlocking the full potential of nanoparticle-stabilized emulsions. The proposed research may offer a general and yet relatively simple strategy to improve the stability of emulsions and prolong the shelf life of widely used pharmaceutical, agricultural, and personal care products. Secondly, the findings may revolutionize the use of nanoparticles for enhanced oil recovery, essential to ensuring national energy independence and addressing the world's energy challenge. Thirdly, understanding the interfacial behavior of nanoparticles will help comprehend the fate of both naturally occurring and engineered nanoparticles in the environment and wastewater treatment processes, such as flotation, which could have an impact on the sustainable use of nanoparticles. Finally, the proposed research may also impact the creation of technologically important materials such as: (1) novel microcapsules with controllable permeability for drug encapsulation and delivery, (2) scrims and polymer blends for composite and membrane applications, and (3) metamaterials that can be further used in cloaking devices and light-based circuits that may ultimately outperform electron-based computers in terms of speed, power consumption, and costs.Education and Outreach: The proposed research will be integrated with educational and outreach activities at all levels to maximize its impact. The graduate and undergraduate students involved in this project will receive cross-discipline training across the fields of rheology, interfacial phenomena, and carbon nanotubes. To engage the younger generation and the local community, culinary foams and emulsions will be used as the theme for the outreach plan. With the support of the CAREER award, the PI and his team will continue their outreach efforts through several programs (e.g., UConn's Mentor Connection Program and da Vinci project) and will attempt a new initiative on introducing basic scientific concepts through debunking cooking myths at high schools in inner-city Hartford and Willimantic with high minority populations.

一个多世纪以来，人们就知道颗粒可以通过吸附在流体-流体界面并降低界面能来稳定乳状液。热力学和早期的实验研究表明，控制颗粒大小和润湿性是稳定乳液的两个关键因素。然而，颗粒形状的影响在很大程度上仍未被探索和利用。这一设想的假设是，颗粒形状很重要，棒状和高长径比的颗粒将增加颗粒-颗粒接触的数量，导致在界面形成更强的层，从而相对于球体形成更稳定的乳状液。为了验证这一假设，我们将研究具有大长径比(1000)的碳纳米管(CNT)作为模型体系。其目的是建立对碳纳米管装饰界面的物理基础的理解。将仔细检查微结构和界面流变性，并进一步将其与碳纳米管负载界面的机械完整性和稳定性联系在一起。这一建议的智能优点包括：(1)探索流体-流体界面上碳纳米管的复杂物理，以及(2)将流变学与界面现象联系起来。更广泛的影响：利用颗粒形状可能是释放纳米颗粒稳定乳液全部潜力的缺失关键。建议的研究可能为提高乳剂的稳定性和延长广泛使用的医药、农业和个人护理产品的货架期提供一种普遍而又相对简单的策略。其次，这些发现可能会彻底改变纳米颗粒用于提高石油采收率的使用，这对于确保国家能源独立和应对世界能源挑战至关重要。第三，了解纳米粒子的界面行为将有助于理解自然产生的和工程制造的纳米粒子在环境和废水处理过程中的命运，如浮选，这可能会对纳米粒子的可持续使用产生影响。最后，拟议的研究还可能影响重要技术材料的创造，例如：(1)用于药物封装和输送的具有可控渗透性的新型微胶囊，(2)用于复合材料和薄膜应用的纱布和聚合物混合物，以及(3)可进一步用于隐形装置和基于光的电路的超材料，这些超材料最终可能在速度、功耗和成本方面优于基于电子的计算机。教育和推广：拟议的研究将与各级教育和推广活动相结合，以最大限度地发挥其影响。参与该项目的研究生和本科生将接受流变学、界面现象和碳纳米管领域的跨学科培训。为了吸引年轻一代和当地社区的参与，将使用烹饪泡沫和乳剂作为外展计划的主题。在职业奖的支持下，PI和他的团队将通过几个项目(例如，康涅狄格州的导师联系计划和达芬奇项目)继续他们的外展努力，并将尝试一项新的倡议，通过在少数族裔人口较多的市中心哈特福德和威利马蒂的高中揭穿烹饪神话来引入基本的科学概念。