Optimizing the Thermodynamics and Kinetics of Nanoparticle Crystal Assembly

优化纳米粒子晶体组装的热力学和动力学

• 批准号: 1907369
• 负责人: Fernando Escobedo
• 金额: $ 30万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2023-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1907369&HistoricalAwards=false
• 关键词: Optimizing; Thermodynamics; Kinetics; Nanoparticle; Crystal

Nanoparticles are materials that have dimensions on the nanometer scale, and they can be assembled into larger materials. The shapes and surface chemistries of nanoparticles can be tailored in ways that atoms or molecules cannot. While spherical nanoparticles with one type of surface coverage or patchy coverage have been studied extensively, other particle shapes that can be prepared, like polyhedra and frames, have been much less explored. This research project aims to devise and validate general computational methods to guide investigators in selecting the key characteristics of arbitrarily-shaped components that lead to their efficient self-assembly into target materials. The outcomes of this research could impact the advanced materials and semiconductor industries by providing principles to design and prepare materials for photonics, photovoltaics, and catalysis applications. The results of this research will be disseminated through presentations at professional meetings, an industrial outreach program organized by Cornell, and a podcast created by graduate students of the Chemical and Biomolecular Engineering (CBE) Department. The research project serves as a training ground for graduate students to perform cutting edge research. An undergraduate student will be recruited to create a multimedia module about engineering self-assembly at the nanoscale to be disseminated through the CBE Women's group outreach initiatives that target rural High School girls. Results from this investigation will also be used in the curriculum of two graduate statistical mechanics courses at Cornell.This research project involves formulating and validating variational principles for enhancing thermodynamic and kinetic assembly behavior. The researchers will implement efficient simulation methods to test and improve the variational principles by applying them to systems containing: (i) hard-core components, (ii) nanoparticles grafted with complementary DNA strands that favor inter-species bonding, (iii) nonconvex shapes where non-additive mixing can occur, and (iv) building blocks that form open lattices. The particle shapes to be investigated include spheres, polyhedra, and frames. The research is based on the hypothesis that the minimization of a free-energy figure of merit can identify how particle-particle interactions should be tuned to enhance their productive assembly into target superlattices. In terms of thermodynamic behavior, it is hypothesized that the free-energy at the order-disorder phase transition should be minimized for optimal stability of pure-component crystals and substitutionally ordered compounds. In terms of kinetic behavior, it is hypothesized that inter-particle interactions that lead to a reduced free-energy barrier height for the disorder-to-order transition, at a fixed degree of supersaturation, correlate with optimal kinetic ability to self-assemble. Advanced methods to map such free-energies as a function of parameters of the system's Hamiltonian will be used to identify optimal values of such parameters. In testing these variational principles, the phase and kinetic behavior of many systems of scientific interest will be mapped out, potentially unveiling new phases and nucleation mechanisms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

纳米颗粒是在纳米尺度上具有尺寸的材料，并且可以组装成较大的材料。 纳米颗粒的形状和表面化学成分可以以原子或分子不能的方式定制。 虽然已经对具有一种表面覆盖或斑块覆盖的球形纳米颗粒进行了广泛的研究，但可以制备的其他粒子形状，例如Polyhedra和Frames，探索较少。 该研究项目旨在设计和验证一般计算方法，以指导研究人员选择任意形状的组件的关键特征，从而将其有效地自组装成目标材料。 这项研究的结果可能会通过提供针对光子学，光伏和催化应用的原理来影响高级材料和半导体行业。 这项研究的结果将通过在专业会议上的演讲，康奈尔（Cornell）组织的工业外展计划以及由化学和生物分子工程（CBE）系的研究生创建的播客中传播。 该研究项目是研究生进行尖端研究的培训理由。 将招募一名本科生，以创建一个多媒体模块，以通过CBE妇女团体宣传计划以针对农村高中女生的CBE妇女团体外展计划进行传播。这项研究的结果还将用于康奈尔大学的两种研究生统计力学课程的课程中。本研究项目涉及制定和验证变异原理，以增强热力学和动力学组装行为。 研究人员将通过将其应用于包含的系统来实施有效的仿真方法来测试和改善变异原理：（i）用互补的DNA链接的纳米颗粒，（ii）有利于物种间键合的纳米颗粒，（iii）非凸形形状在可能发生非加性混合的地方，以及（iv）形成开放格子的构建块。要研究的粒子形状包括球体，多面体和框架。该研究基于以下假设：自由能的功绩数字最小化可以确定应如何调整粒子粒子相互作用以增强其生产力组装到目标超晶格中。在热力学行为方面，假设应将订购级相变的自由化自由能最小化，以使纯组分晶体的最佳稳定性和替代有序的化合物的最佳稳定性。在动力学行为方面，假设粒子间相互作用会导致降低的自由能屏障高度以固定的过饱和度降低，以降低疾病的过渡，这与最佳的自我组成能力相关。将这些自由能作为系统哈密顿量参数的函数映射的高级方法将用于识别此类参数的最佳值。在测试这些变异原理时，将绘制许多科学意义系统的阶段和动力学行为，可能揭示新的阶段和成核机制。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点通过评估来支持的。和更广泛的影响审查标准。

项目成果

Effect of particle anisotropy on the thermodynamics and kinetics of ordering transitions in hard faceted particles

颗粒各向异性对硬面颗粒有序转变热力学和动力学的影响

• DOI: 10.1063/5.0135461
• 发表时间: 2023
• 期刊: The Journal of Chemical Physics
• 作者: Sharma, Abhishek K.;Escobedo, Fernando A.
• 通讯作者: Escobedo, Fernando A.

Influence of Nonadditive Mixing on Colloidal Diamond Phase Formation from Patchy Particles

非加成混合对片状颗粒形成胶体金刚石相的影响

• DOI: 10.1021/acs.jpcb.3c00708
• 发表时间: 2023
• 期刊: The Journal of Physical Chemistry B
• 作者: Matos, Isabela Quintela;Escobedo, Fernando A.
• 通讯作者: Escobedo, Fernando A.

On the calculation of free energies over Hamiltonian and order parameters via perturbation and thermodynamic integration

通过微扰和热力学积分计算哈密顿量和有序参数的自由能

• DOI: 10.1063/5.0061541
• 发表时间: 2021
• 期刊: The Journal of Chemical Physics
• 作者: Escobedo, Fernando A.

Bridging hexatic and tetratic phases in binary mixtures through near critical point fluctuations

通过近临界点波动桥接二元混合物中的六方相和四方相

• DOI: 10.1103/physrevmaterials.5.024003
• 发表时间: 2021
• 期刊: Physical Review Materials
• 影响因子: 3.4
• 作者: Prajwal, B. P.;Escobedo, Fernando A.
• 通讯作者: Escobedo, Fernando A.