NER: Nanoparticle Stability by Quantum Design of Van der Waals Forces

NER：通过范德华力的量子设计实现纳米粒子稳定性

• 批准号: 0403646
• 负责人: Darrell Velegol
• 金额: $ 13万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2006-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0403646&HistoricalAwards=false
• 关键词: NER; Nanoparticle; Stability; Quantum; Design

AbstractCTS-0403646D. Velegol, Pennsylvania State UniversityNanotechnology promises huge advances in materials, optical, electronics, and biomedicalapplications. Current top-down techniques (e.g., atomic force microscopy, e-beam lithography) for creating nanoscale products are slow and expensive, making them difficult to use for bulk production of quantum dots, nanostructured catalysts, nanoparticle lubricants, advanced nanoparticle drug vectors, and other nano products. A more viable approach to consumer-scale production is "bottom up assembly", in which smart particles self-assemble into structures. A critical bottleneck to nanoparticle use is the dispersion and self-assembly of functional particles. The challenge is that van der Waals (VDW) forces cause non-specific and undesired aggregation of the particles.Current techniques for stabilizing particles - especially the use of dispersants - limit the ability tofunctionalize the particles. To achieve nanoparticle dispersion, new methods must be identified for reducing VDW attractive forces. These forces always exist between atoms and molecules, and they have been studied in various contexts for 75 years. But the issues involved with calculating VDW forces for nanoparticles open a new field of study, since nanoparticle VDW forces are different from those for micron size particles or atoms.Intellectual merit: The vision of this NSF NER is to explore the design of nanoparticle systems that are inherently stable, using quantum principles. Our preliminary calculations suggest new opportunities for tuning VDW forces, perhaps even making them repulsive. Precise techniques for tuning VDW forces are highly unlikely to emerge from experiments alone, due to the huge parameter space involved. Quantum calculations are essential to the success of this project. In this NER we will ... 1. develop the tool chest needed to model accurately the VDW forces for nanoparticles, andprogram this into "BottomUp" software to make it easily available to nanotechnologists;2. calculate VDW forces for technologically-relevant systems, including core-shell nanoparticlesand nanoparticles in various co-solvent systems;3. assess the accuracy of the calculations using turbidity stability experiments.This novel modeling will enable us to explore the huge parameter space - particle material, size,morphology, core-shell structure, co-solvent media, etc. - that is not only unmeasurable currently, but also which requires design techniques to navigate. Going beyond current paradigms for atomic or micron-size systems, we will consider effects of crystal structures and discrete atoms, altered polarizabilities of nanoparticles, and core-shell and co-solvent systems. Our approach will use techniques well-known in the atomic VDW force literature, and transform them for use on nanoparticle systems. In this NER we seek support for early-stage calculations that will demonstrate the feasibility of the "design" approach for nanoparticle system dispersion. The proposal addresses the modeling and simulation at the nanoscale theme, as well as the manufacturing processes at the nanoscale theme, since our goal is to enable the bulk production and processing of nanoparticle systems. Broader impact: This research will have two broader impacts. The first is "BottomUp", the software tool that will embody our calculations. The vision for this novel piece of freeware infrastructure is that a nanotechnologist can enter systems parameters (e.g., materials, particle sizes and volume fraction) and receive specific suggestions for dispersing the nanoparticles based on the most powerful calculations available for nanoparticle VDW forces and stability. In the longer term, BottomUp will be a user-friendly tool that will be extended to other types of forces, including electrostatic, depletion, and hydrophobic forces. The second broader impact comes from leveraging existing strengths with "Action Potential", a Penn State program that exposes 10 to 14 year olds to a stimulating science experience. Collaborations with this organization will aim to inspire students to learn and use modern physics for applied problems.

摘要CTS-0403646 D。Velegol，宾夕法尼亚州立大学纳米技术承诺在材料，光学，电子和生物医学应用的巨大进步。当前自上而下的技术（例如，原子力显微镜、电子束光刻）用于产生纳米级产品是缓慢且昂贵的，使得它们难以用于量子点、纳米结构催化剂、纳米颗粒润滑剂、高级纳米颗粒药物载体和其它纳米产品的批量生产。一种更可行的消费级生产方法是“自下而上的组装”，即智能粒子自组装成结构。纳米粒子应用的一个关键瓶颈是功能粒子的分散和自组装。挑战在于货车德瓦尔斯（VDW）力导致非特异性和不希望的颗粒聚集。目前稳定颗粒的技术--特别是分散剂的使用--限制了颗粒功能化的能力。为了实现纳米颗粒分散，必须确定新的方法来减少VDW吸引力。这些力总是存在于原子和分子之间，75年来人们一直在各种背景下研究它们。但是计算纳米粒子的VDW力所涉及的问题开辟了一个新的研究领域，因为纳米粒子的VDW力与微米尺寸的粒子或原子的VDW力不同。智力价值：NSF NER的愿景是利用量子原理探索内在稳定的纳米粒子系统的设计。我们的初步计算表明，新的机会，调整VDW部队，甚至使他们排斥。精确的技术调整VDW力是极不可能出现的实验本身，由于涉及的巨大的参数空间。量子计算对这个项目的成功至关重要。在这场比赛中，我们将…1.开发准确建模纳米颗粒VDW力所需的工具箱，并将其编程到“BottomUp”软件中，使纳米技术专家可以轻松使用它;2.计算技术相关系统的VDW力，包括核-壳纳米颗粒和各种共溶剂系统中的纳米颗粒;3.通过浊度稳定性实验评估计算的准确性。这种新颖的建模将使我们能够探索巨大的参数空间-颗粒材料，尺寸，形态，核壳结构，共溶剂介质等-这不仅是目前无法测量的，而且需要设计技术来导航。超越目前的原子或微米尺寸系统的范例，我们将考虑晶体结构和离散原子的影响，改变纳米粒子的极化率，核壳和共溶剂系统。我们的方法将使用原子VDW力文献中众所周知的技术，并将其转换为用于纳米颗粒系统。在这个NER中，我们寻求支持的早期阶段的计算，这将证明纳米粒子系统分散的“设计”方法的可行性。该提案涉及纳米级主题的建模和模拟，以及纳米级主题的制造工艺，因为我们的目标是实现纳米颗粒系统的批量生产和加工。更广泛的影响：这项研究将产生两个更广泛的影响。第一个是“自下而上”，这是一个将体现我们计算的软件工具。这种新的免费软件基础设施的愿景是，纳米技术专家可以输入系统参数（例如，我们的团队可以提供最新的数据（包括材料、粒度和体积分数），并根据最强大的纳米颗粒VDW力和稳定性计算，获得分散纳米颗粒的具体建议。从长远来看，自下而上将是一个用户友好的工具，将扩展到其他类型的力量，包括静电，消耗和疏水力。第二个更广泛的影响来自于利用现有的优势与“行动潜力”，宾夕法尼亚州立大学的一个项目，使10至14奥尔兹接触到一个刺激的科学经验。与该组织的合作旨在激励学生学习和使用现代物理学解决应用问题。