NIRT: Environmentally Benign Deagglomeration and Mixing of Nanoparticles

该奖项是为了响应纳米科学与工程倡议，NSF 04-043，类别NIRT。纳米颗粒和纳米复合材料提供了独特的性能，这些性能来自于它们的小尺寸，大表面积以及它们界面处的相的相互作用，并且由于它们在改善药物，生物材料，催化剂和其他高附加值材料的性能方面的潜力而具有吸引力。然而，利用纳米颗粒的一个主要问题是，由于晶粒生长或重要的高表面积不可用，它们经常失去高表面积。产生其中两种或更多种纳米级成分紧密混合的纳米结构复合材料可以防止表面积的这种损失，但是为了获得均匀的混合，各个纳米颗粒成分的解团聚是必要的。超临界流体（SCF），例如超临界二氧化碳，具有液体状的密度和溶解度，但具有气体状的扩散性和粘度，并且是环境友好的，是用于解聚纳米颗粒的目的的理想介质，因为它可以渗透纳米团聚体内的孔，并且在快速减压时，可以引起纳米团聚体从内部破碎和分离。使用超临界流体生产混合良好的纳米复合材料具有许多优点：不需要有机溶剂甚至水，在接近室温下进行加工，避免了高水平的压缩应力或摩擦力，并且由于不使用液体，因此消除了干燥和溶剂去除的成本，并且保持了物质纯度。结合实验和多尺度模拟，在三个不同的长度尺度，是必要的，以获得一个基本的科学理解的解聚和随后的混合过程。 该奖项旨在发展这些核心知识，将推进纳米材料领域。由于一个全面的教育和培训计划，包括从K-12到研究生水平的学生，该项目将在劳动力发展和公众对纳米技术的认识方面产生更广泛的影响。实验和理论研究将提供预测能力，这将有助于优化和扩大规模，以及随后的技术转让给工业合作伙伴。因此，这项工作有可能演变成大量生产纳米复合材料的主要技术，并有助于建立美国在纳米混合领域的领导地位。为了实现这一多学科的研究和教育目标，来自四所大学（NJIT，罗格斯大学，普林斯顿大学和奥本）的一个非常有才华的研究人员团队已经组装。该团队致力于建立在他们过去的成功研究，并通过招聘，辅导和保留代表性不足的少数民族和女学生多管齐下的努力，在整合多样性。

This award was received in response to Nanoscale Science and Engineering initiative, NSF 04-043, category NIRT. Nanoparticles and nanocomposites offer unique properties that arise from their small size, large surface area, and the interactions of phases at their interfaces, and are attractive for their potential to improve performance of drugs, biomaterials, catalysts and other high-value-added materials. However, a major problem in utilizing nanoparticles is that they often lose their high surface area due to grain growth or unavailability of the high surface area where it matters. Creating nanostrauctured composites where two or more nanosized constituents are intimately mixed can prevent this loss in surface area, but in order to obtain homogeneous mixing, de-agglomeration of the individual nanoparticle constituents is necessary. A supercritical fluid (SCF), such as supercritical carbon dioxide, which has liquid-like density and solubility, yet gas-like diffusivity and viscosity, and is environmentally friendly, is an ideal medium for the purpose of deagglomerating nanoparticles because it can penetrate the pores within the nano-agglomerates, and upon rapid depressurization, can cause fragmentation and separation of the nanoagglomerates from within. The use of a SCF for producing well-mixed nanocomposites has a number of advantages: no organic solvents or even water is required, the processing is done at near room temperature, high levels of compressive stresses or friction forces are avoided, and since liquids are not used the cost of drying and solvent removal is eliminated, and substance purity is preserved. A combination of experiments and multiscale simulations, at three different length scales, is necessary to obtain a fundamental scientific understanding of the deagglomeration and subsequent mixing processes. This award is aimed at developing such core knowledge that will advance the field of nano-materials.Due to a comprehensive education and training program that includes students from K-12 through postgraduate levels, the project will have broader impacts in terms of workforce development and public awareness of nanotechnology. The experimental and theoretical research will provide predictive capabilities that will help in optimization and scale-up, and subsequent technology transfer to industrial partners. Thus this work has the potential to evolve into major enabling technologies for producing nanocomposites in large quantities, and contribute to establishing a leadership position for the US in the nanomixing area. To carry out this multidisciplinary research and educational objectives, a highly talented team of researchers from four universities (NJIT, Rutgers, Princeton and Auburn) has been assembled. This team is committed to building upon their past successes in research and in integrating diversity through a multi-pronged effort on recruitment, mentoring, and retention of underrepresented minority and women students.