NIRT: Environmentally Benign Deagglomeration and Mixing of Nanoparticles

该奖项是对NSF 04-043 NIRT类纳米科学与工程倡议的响应。纳米颗粒和纳米复合材料因其尺寸小、比表面积大以及界面相之间的相互作用而具有独特的性质，并因其在改善药物、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受到人们的关注。然而，利用纳米粒子的一个主要问题是，由于颗粒生长或无法获得重要的高表面积，它们经常失去其高表面积。创建两个或两个以上纳米组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，但为了获得均匀的混合，单个纳米粒子组分的解聚是必要的。超临界流体(SCF)，如超临界二氧化碳，具有类似液体的密度和溶解度，但具有类似气体的扩散性和粘度，并且对环境友好，是用于纳米团聚的理想介质，因为它可以穿透纳米团聚体内的孔隙，并且在快速降压时，会导致纳米团聚从内部破碎和分离。使用超临界流体制备混合良好的纳米复合材料具有许多优点：不需要有机溶剂，甚至不需要水，加工过程在接近室温的情况下进行，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，并保持了物质的纯度。在三个不同的长度尺度上进行实验和多尺度模拟的结合，对于获得对解聚和随后的混合过程的基本科学理解是必要的。该奖项旨在发展这些将推动纳米材料领域发展的核心知识。由于一个包括从K-12到研究生水平的全面教育和培训计划，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，有助于优化和扩大规模，以及随后向行业合作伙伴转让技术。因此，这项工作有可能演变为大量生产纳米复合材料的主要使能技术，并有助于建立美国在纳米混合领域的领先地位。为了实现这一多学科研究和教育目标，来自四所大学(NJIT、罗格斯大学、普林斯顿大学和奥本大学)的一支才华横溢的研究团队已经组建起来。这个团队致力于在过去研究成功的基础上，通过多管齐下的努力，在招聘、辅导和留住代表不足的少数族裔和女性学生方面整合多样性。

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.