High Efficiency Nanoparticulate Emulsifiers

高效纳米颗粒乳化剂

• 批准号: 0729967
• 负责人: Robert Tilton
• 金额: $ 24万
• 依托单位: Carnegie-Mellon University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0729967&HistoricalAwards=false
• 关键词: Efficiency; Nanoparticulate; Emulsifiers

National Science Foundation - Division of Chemical &Transport Systems ? Particulate & Multiphase Processes Program (1415)Proposal Number: 0729967Principal Investigators: Tilton, RobertAffiliation: Carnegie Mellon University Proposal Title: High Efficiency Nanoparticulate EmulsifiersIntellectual Merit. Emulsions stabilized by colloidal particles adsorbed at the oil/water interface, commonly called Pickering emulsions, are distinguished by their superior stability against coalescence and sedimentation and by their ability to disperse high discontinuous phase volume fractions. We propose to develop novel nanoparticulate emulsifiers with extremely high emulsification efficiency. Atom transfer radical polymerization (ATRP) will be used to create nanoparticle-grafted, amphiphilic copolymer brushes with well-controlled architectures designed to drive particles to adsorb with high affinity and stabilize the oil/water interface. We will prepare two categories of nanoparticulate emulsifiers. The first type has a silica core with copolymer amphiphiles grafted from or to its surface. The second type are multi-arm miktoarm star polymers with dense polymer cores surrounded by two or more types of extended arms. These grafted brush particles have more degrees of freedom than conventional particulate emulsifiers that may allow for finer tuning of interfacial thermodynamic and mechanical properties. The conformation of the amphiphilic brushes will adapt to the local solvent environment as particles adsorb to the oil/water interface. In developing the most effective emulsifiers, the underlying mechanistic relationships between brush architecture and emulsification will be determined. The main technological goal is for the proposed nanoparticle-grafted brushes to stabilize emulsions at concentrations at least ten times smaller than are required for current particulate emulsifiers. Some of the proposed structures may be thermally responsive to de-emulsify in response to temperature cues. Broader Impact. The proposed work will form the interdisciplinary training of a Chemical Engineering Ph.D. student and for part of a Chemistry Ph.D. student's training. Both will be trained in the design and physical characterization of functional materials as well as state-of-the-art controlled radical polymerization techniques. A secondary school outreach program will be developed on themes of interfacial engineering, whereby public school science teachers spend one or two summer months in the PI's lab to develop student lab modules and lesson plans on the role of interfaces in nature and materials. There will be an everyday materials theme involving vegetable oil/water Pickering emulsions and a ?novelties? theme that builds on the science of particle-stabilized interfaces to understand how so-called ?liquid marbles? (Aussillous, P.; Quearea, D., Nature 2001, 411, 924-927) work. The PI will provide the essentials of interfacial thermodynamics and help the teacher prepare lesson plans on capillary forces and their occurrence in nature. The PI will subsequently join the teacher as a guest in the classroom. This research will deliver copolymer-grafted particulate emulsifiers that set the mark for emulsification efficiency, together with the brush design principles needed to meet new applications in any industry that relies on emulsions (agriculture, foods, personal care?). New applications may be made possible by significant improvements in particulate emulsifiers. For example, diesel emulsions combust more cleanly than conventional diesel fuel, and emulsifier formulation is a major challenge.

美国国家科学基金会化学与运输系统分部？颗粒和多相过程计划（1415）提案编号：0729967主要研究人员：Tilton， robert隶属关系：卡内基梅隆大学提案标题：高效纳米颗粒乳化剂智力价值。由吸附在油/水界面的胶体颗粒稳定的乳状液，通常称为皮克林乳状液，其特点是具有优异的抗聚结和沉积稳定性，并具有分散高不连续相体积分数的能力。我们建议开发具有极高乳化效率的新型纳米颗粒乳化剂。原子转移自由基聚合（ATRP）将用于制造纳米颗粒接枝的两亲性共聚物刷，其结构控制良好，旨在驱动颗粒以高亲和力吸附并稳定油/水界面。我们将制备两类纳米颗粒乳化剂。第一种类型具有从其表面接枝或接枝共聚物两亲体的二氧化硅核。第二种类型是多臂密臂星形聚合物，密集的聚合物芯被两种或两种以上的延伸臂包围。这些接枝的刷状颗粒比传统的颗粒乳化剂具有更多的自由度，可以更精细地调整界面热力学和机械性能。当颗粒吸附在油/水界面时，两亲性刷的构象将适应当地的溶剂环境。在开发最有效的乳化剂时，将确定电刷结构与乳化之间的潜在机制关系。主要的技术目标是提出纳米颗粒接枝刷，以稳定乳液的浓度至少比目前的颗粒乳化剂所需的浓度小十倍。一些提出的结构可能对温度线索的脱乳有热响应。更广泛的影响。建议的工作将构成化学工程博士生的跨学科培训和化学博士生培训的一部分。两者都将在功能材料的设计和物理特性以及最先进的控制自由基聚合技术方面进行培训。一项以界面工程为主题的中学拓展计划将被开发，公立学校的科学教师将在PI的实验室中花一到两个月的时间来开发学生实验模块和课程计划，以了解界面在自然和材料中的作用。将会有一个日常材料的主题，包括植物油/水皮克林乳液和一些新奇的东西。那建立在粒子稳定界面科学基础上的主题如何理解呢？液体弹珠吗?（Aussillous， P.; Quearea， D., Nature 2001, 411, 924-927）PI将提供界面热力学的基本知识，并帮助教师准备有关毛细力及其在自然界中的存在的教案。PI随后将作为嘉宾加入老师的课堂。这项研究将提供共聚物接枝颗粒乳化剂，为乳化效率树立标杆，同时提供所需的刷设计原则，以满足任何依赖乳剂的行业（农业、食品、个人护理？）的新应用。微粒乳化剂的重大改进可能使新的应用成为可能。例如，柴油乳化液燃烧起来比传统柴油燃料更清洁，乳化剂的配方是一个主要挑战。