Rheology of Nanosize Powder Suspensions

纳米粉末悬浮液的流变学

• 批准号: 0931038
• 负责人: Mufit Akinc
• 金额: $ 30万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0931038&HistoricalAwards=false
• 关键词: Rheology; Nanosize; Powder; Suspensions

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5) 0931038AkincIntellectual MeritThe rheological behavior of highly loaded, nanosize powder suspensions presents scientific and technological challenges. As the particle size approaches nanoscale, the viscosity of the suspension increases sharply. When the solids content approaches 30 vol, the viscosity becomes intractable. However, we recently discovered that mono and disaccharides (i.e. fructose and sucrose) dramatically decrease the viscosity of nano alumina suspensions. The primary objective of the proposed research is to understand the rheological behavior of highly loaded nanosize powder suspensions where particle potential fields overlap, thus flocculation becomes a serious concern. An additional objective is to understand the dramatic role low molecular weight (MW) saccharides play in reducing the viscosity. We will investigate the molecular level interactions between particle surface, water, and saccharide molecules to establish a relationship between characteristics of saccharide molecule and the viscosity of the suspension. The intellectual merit of this project lies in the fact that, upon completion, we will be able to describe the flow behavior of nanosize powder suspensions in aqueous sachharide solution where surface chemistry plays a significant role. Specifically, experiments with strain rate programmed rheometry; sub zero temperature differential scanning calorimetry (SZT-DSC); colloidal probe atomic force microscopy (CP-AFM); and variable temperature 1H, 1H-27Al, and 13C nuclear magnetic resonance (NMR) spectroscopy experiments will be carried out as functions of solids composition and content, saccharide type and concentration. Integrating interparticle potential to the viscosity expression and modifying the particle packing due to clustering and/or bound water will allow us to quantitatively describe flow behavior of nano powder suspensions and control of viscosity with saccharide or similar additives.Broader ImpactNano owder suspensions find applications in ultra thin dielectrics, solid oxide fuel cells, membranes, coatings, abrasive polishing, adhesives, and sunscreens, among others. A practical consequence of this research will be the elucidation of how the viscosity varies with the solids content and its surface chemistry, and how low MW saccharides reduce the viscosity. The results from this research will enable us to control the flow behavior of many nanoparticle suspensions, and formulate high solids content, low viscosity suspensions that are consolidated to components with features in the nanoscale. Therefore, this project has significant broader impacts on diverse industries that have multi billion dollar revenues. This project will allow education of a graduate student in the nanosize powder processing science. For this, a domestic female student will be recruited. Approximately 40% of PIs grad students in the last decade were female. In addition, undergraduate students preferably from underrepresented groups will be recruited through Freshman Mentor Program and the Program for Women in Science and Engineering. Over the years, the PI has employed, on the average, two undergraduate students per year in his research group. The PI has produced an educational video Materials Matter to be distributed ASM International across the country to recruit students to engineering, in particular MSE. PI has also developed a short video clip based on the current research topic: Viscosity of Suspensions: Magic or Science. We intend to make short video clip again to be distributed broadly across the country via internet. Also an undergraduate laboratory experiment demonstrating the variation of viscosity with saccharide concentration will be developed and implemented in Ceramic Processing course that the PI teaches every year. Use of sub zero temperature DSC, variable temperature NMR, and sophisticated colloidal probe AFM experiments for measuring interparticle forces directly will allow scientists in other fields to implement these techniques in broad range of fields,

该奖项是根据2009年美国复苏和再投资法案（公法111-5）0931038 AkincIntellectual MeritThe流变行为的高负荷，纳米级粉末悬浮液提出了科学和技术的挑战。随着颗粒尺寸接近纳米级，悬浮液的粘度急剧增加。当固体含量接近30体积%时，粘度变得难以控制。然而，我们最近发现，单糖和二糖（即果糖和蔗糖）显着降低纳米氧化铝悬浮液的粘度。 所提出的研究的主要目标是了解高负载纳米级粉末悬浮液的颗粒势场重叠的流变行为，从而絮凝成为一个严重的问题。另一个目的是了解低分子量（MW）聚合物在降低粘度方面的重要作用。我们将研究颗粒表面、水和糖分子之间的分子水平相互作用，以建立糖分子特性与悬浮液粘度之间的关系。该项目的智力价值在于，完成后，我们将能够描述纳米粉末悬浮液在表面化学起着重要作用的sachharide水溶液中的流动行为。具体而言，将根据固体组成和含量、糖类型和浓度进行应变速率程序化流变测定实验;零度以下差示扫描量热法（SZT-DSC）;胶体探针原子力显微镜（CP-AFM）;以及变温1H、1H-27 Al和13 C核磁共振（NMR）光谱实验。整合粒子间的潜力的粘度表达式和修改的颗粒包装，由于集群和/或结合水将使我们能够定量描述纳米粉末悬浮液的流动行为和控制粘度与糖或类似additives.Broader ImpactNano owder悬浮液中发现的应用在超薄电介质，固体氧化物燃料电池，膜，涂料，研磨抛光，粘合剂，防晒霜，等等。这项研究的一个实际结果将是阐明粘度如何随固体含量和表面化学变化，以及低分子量聚合物如何降低粘度。这项研究的结果将使我们能够控制许多纳米颗粒悬浮液的流动行为，并配制高固体含量，低粘度的悬浮液，这些悬浮液被合并为具有纳米级特征的组件。因此，该项目对拥有数十亿美元收入的不同行业产生了广泛的影响。 该项目将允许在纳米级粉末加工科学的研究生教育。为此，将招募一名国内女学生。在过去的十年中，大约40%的PI格拉德生是女性。此外，将通过新生导师方案和科学和工程领域妇女方案，招收最好来自代表性不足群体的本科生。多年来，PI平均每年在他的研究小组中雇用两名本科生。 PI制作了一个教育视频Materials Matter，将在全国范围内分发ASM International，以招收工程学学生，特别是MSE学生。PI还根据当前的研究主题开发了一个简短的视频剪辑：悬浮液的粘度：魔术还是科学。我们打算再次制作短片，通过互联网在全国范围内广泛传播。此外，一个本科生实验室实验表明粘度与糖浓度的变化将开发和实施陶瓷加工课程，PI教每年。 使用零度以下的DSC、变温NMR和精密的胶体探针AFM实验直接测量颗粒间的力，将使其他领域的科学家能够在广泛的领域实施这些技术，