Theory and computation for self-assembly in soft matter

西北大学的George Schatz在化学系化学理论、模型和计算方法计划的支持下，开发了将大分子组装成功能纳米结构的模型的理论和计算方法。这项拟议的工作建立在PI在该领域保持的一项积极计划的基础上，该计划涉及与机械、电气和光学设备以及生物医学应用相关的软材料。这些方法的范围从强力分子动力学方法，到加速和粗粒度方法，到简单的统计力学模型，以及将分子和连续方法结合在一起的多尺度方法。这些方法与组装的模板、播种和机械控制方法相结合，以开发出比其他方法更有效的方法，或者提供对驱动组装的特征的更好的洞察。合作者正在进行的实验模拟将包括：(1)种子方法，以加速多肽两亲性分子组装成胶束和更复杂的结构，用于伤口愈合应用；(2)多尺度方法，应用于涂有交联聚合物(经分子动力学处理)的脂质体(经分子动力学处理)，以研究药物输送应用中的涂层形成和破裂；(3)模板化方法，用于研究在Au(111)表面的纳米漂流自组装单分子膜的加速组装机制，以及在金纳米粒子表面的加速DNA杂交；以及(4)机械引导的DNA自组装，将纳米颗粒或分子连接成聚集结构，研究机理信息，并能够研究盐、多电荷阳离子、非水溶剂以及可能的先驱者？促进氢键形成的分子这个项目关注的是将数千个分子有组织地组装成更大的结构(纤维、表面涂层、凝胶状材料)的计算模型，这些结构具有有用的生物和材料功能，包括应用于伤口愈合、药物输送、治疗和诊断。这项工作涉及开发新的计算方法，可以预测将形成什么结构，这些结构如何随着制备条件的变化而变化，以及这些结构的生物功能。拟议的研究项目将由本科生、研究生和博士后进行，他们将接受正在使用的理论和方法以及正在开发的材料的制作和应用方面的培训。外联活动包括：(1)软件传播，特别是利用www.nanhub.org网站，在该网站上可免费获取代码的功能版本，包括文件和实例；(2)编写与自组装有关的教材，用于普通化学课程、讲座和实验室；(3)通过一个化学组织(Phi Lambda Upsilon)在以少数族裔为主的地方学校推广使用自组装研究材料；(4)与出版伦理有关的课程和外联活动；(5)夏季REU项目，包括少数民族学生；(6)与《物理化学杂志》有关的与自组装研究有关的活动；(7)在重大科学会议和访问大学和实验室时向包括普通公众在内的受众介绍情况；(8)向研究生和博士后提供咨询和指导，包括少数民族和女性。

George Schatz of Northwestern University is supported by the Chemical Theory, Models and Computational Method program in the Division of Chemistry to develop theory and computational methods for modeling the self-assembly of large assemblies of molecules into functional nanostructures. The proposed work builds on an active program that the PI maintains in this field concerning soft materials that are relevant to mechanical, electrical and optical devices, and for biomedical applications. The methods span the range from brute force molecular dynamics methods, to accelerated and coarse-grained methods, to simple statistical mechanical models, and to multiscale methods that couple molecular and continuum approaches. These are combined with methods for templating, seeding and mechanical control of assembly to develop approaches that are either significantly more efficient than can otherwise be obtained or which provide better insights into the features that drive assembly. Modeling of on-going experiments by collaborators will include (1) seeded methods to accelerate assembly of peptide amphiphiles into micelles and more complex structures that are of use in wound healing applications; (2) a multiscale method applied to a liposome (treated by continuum mechanics) coated with a cross-linked polymer (treated by molecular dynamics) to study coating formation and bursting in drug delivery applications; (3) templated approaches for investigating the mechanism for accelerated assembly in nanografting self-assembled monolayers on Au(111) surfaces as well as accelerated DNA hybridization on gold nanoparticles surfaces; and (4) mechanically guided self-assembly for DNA linking of nanoparticles or molecules into aggregated structures, investigating mechanistic information and enabling studies of the effects on the assembly process of salts, multiply charged cations, nonaqueous solvents, and possibly ?pioneer? molecules that facilitate hydrogen bond formation.This project is concerned with computational modeling of the organized assembly of thousands of molecules into larger structures (fibers, surface coatings, gel-like materials) that have useful biological and materials functions, including applications to wound healing, to drug delivery, to therapeutics and diagnostics. The work involves the development of new computational methods which can predict what structures will form, how these structures vary with variations in the preparation conditions, and the biological functions of these structures. The proposed research projects will be pursued by undergraduate, graduate and postdoctoral students, and they will receive training in the theory and methods being used, and in the fabrication and applications of the materials being developed. Outreach activities include: (1) Software dissemination, particularly using the www.nanohub.org site where access to functioning versions of the codes is available for free, and includes documentation and examples; (2) The development of teaching materials related to self-assembly that are used in General Chemistry courses, both lectures and laboratories; (3) Use of self-assembly research materials in outreach at predominantly minority local schools through a chemistry organization (Phi Lambda Upsilon); (4) Courses and outreach activities related to publication ethics; (5) Summer REU projects, including minority students, (6) Activities associated with the Journal of Physical Chemistry which relate to self-assembly research; (7) Presentations to audiences, including the general public, at major scientific meetings and in visits to universities and laboratories; (8) Advising and mentoring graduate students and postdocs, including minorities and females.