GOALI: Multiscale Modeling of Adsorption Equilibrium and Dynamics in Polymer Chromatography

这个项目将研究吸附的临界条件，它允许大分子在化学组成、微观结构和拓扑结构方面进行不依赖分子量的分离。基于测量细胞蒙特卡罗模拟、自一致场理论和随机Fokker-Plank扩散方程的新型建模方法将用于聚合物吸附平衡和动力学的研究。这些方法将应用于杜邦收集的线性均聚物和共聚物的不依赖分子量分离的实验数据，并以典型的色谱二元溶剂在未改性和改性不同孔结构的二氧化硅衬底上分离的苯乙烯-丁二烯体系为例进行验证。链分子在纳米结构表面和纳米孔内的吸附是聚合物色谱分离和表征的关键机制，通常用于化学和石油工业的几乎所有分支，以及生物和医学。目前，新应用的分离方法是通过试错方法开发的。开发新的色谱方法的主要障碍是缺乏一个足够的理论来描述大分子在具有吸附表面的限制性多孔介质中的行为，因此，缺乏对保留机制和孔隙结构效应（如孔隙大小和形状）的基本理解。该计划的目标是设计新的分子模拟工具，能够预测纳米孔底物上链分子的平衡分配和动力学，并推进对聚合物色谱中保留的物理化学机制的基本理解。拟议项目的成功将使开发一种战略方法来指导优化聚合物色谱的条件。这种新的模拟方法可以在聚合物色谱之外的复杂大分子体系的建模中找到各种应用。它们可以通过生物和固态纳米孔，生物聚合物测序和噬菌体中的DNA包装扩展到DNA和蛋白质易位问题。提高对大分子与纳米结构和多孔基底相互作用的物理化学机制的理解是合理设计新型纳米复合材料、表面聚合物修饰、药物片剂和薄膜的关键。这项研究的结果将具有重大的跨学科变革影响，因为它解决了目前未解决的主题问题，这些问题在不同的化学和生物医学技术中很常见，并专注于开发和测试创新的建模工具，这些工具可以适应并用于模拟和优化涉及聚合物和生物聚合物在纳米结构基质和膜上的吸附和扩散的各种过程。比如DNA测序和包装。该研究项目和少数民族学生招募将与目前的NSF纳米药物研究项目和NSF结构化有机微粒系统研究项目（ERC- sops）协调；PI是这些项目的教员研究员。少数民族本科生将通过REU计划招收；PI有监督REU少数民族学生的既定记录。在ERC-SOPS的协助下，将为新泽西州州长工程技术学院和教育培训学院的K-12学生和教师准备一个关于“聚合物和纳米颗粒”的特别研究模块。这项工作的成果将通过同行审查的出版物、在国家和国际会议上的介绍以及建立一个专门的网页来传播，以便为教育目的提供项目报告和介绍。新的模拟方法和案例研究系统将被纳入PI为IGERT课程开发的新研究生课程“纳米尺度热力学和输运”中。学生将受益于杜邦实验站的工业培训和研究设施。在工业Co-PI的指导下，他们将制作实际相关的计算机程序，并获得色谱实验的实践经验。

1064170NeimarkThis project will research critical conditions of adsorption, which allow for molecular weight-independent separation of macromolecules with respect to their chemical composition, microstructure, and topology. Novel modeling methods based on gauge cell Monte Carlo simulation, selfconsistent field theory, and stochastic Fokker-Plank diffusion equation, will be elaborated and tested for studies of polymer adsorption equilibrium and dynamics. These methods will be applied to and verified with experimental data collected at DuPont on molecular weight-independent separation of linear homopolymers and copolymers with the example of styrene-butadiene systems separated on unmodified and modified silica substrates of different pore structure in typical chromatographic binary solvents. Adsorption of chain molecules on nanostructured surfaces and within nanoscale pores is the key mechanism of chromatographic separation and characterization of polymers, which is commonly employed in almost all branches of chemical and petroleum industries, as well as in biology and medicine. Currently, separation methods for new applications are developed by trial-and-error approaches. The main obstacle in developing new chromatographic processes is the absence of an adequate theory describing the behavior of macromolecules within confining porous medium with adsorbing surfaces, and, as the result, the lack of a fundamental understanding of the mechanism of retention and the pore structure effects, such as pore size and shape. The objective of the proposed program is to design novel molecular simulation tools capable of predicting equilibrium partitioning and dynamics of chain molecules on nanoporous substrates and to advance fundamental understanding of the physico-chemical mechanisms of retention in polymer chromatography. The success of the proposed project will enable the development of a strategic approach to guided optimization of the conditions of polymer chromatography. The novel simulation methods may find various applications in modeling of complex macromolecular systems beyond polymer chromatography. They can be extended to the problems of DNA and protein translocation through biological and solid state nanopores, biopolymer sequencing, and DNA packaging in bacretiophages. Improved understanding of the physico-chemical mechanisms of interactions of macromolecules with nanostructured and porous substrates is the key for a rational design of novel nanocomposites, polymer modification of surfaces, pharmaceutical tablets, and films. The results of this research will have a significant transformative interdisciplinary impact since it addresses currently unresolved topical problems that are common across different chemical and biomedical technologies, and focuses on developing and testing innovative modeling tools that can be adapted and employed for simulation and optimization of various processes which involve polymer and biopolymer adsorption and diffusion on nanostructured substrates and membranes, such DNA sequencing and packaging. The research project and minority student recruitment will be coordinated with the current NSF IGERT program on Nano-Pharmaceuticals and NSF ERC project on Structured Organic Particulate Systems (ERC-SOPS); the PI is a faculty researcher in these projects. Minority undergraduate students will be recruited through the REU initiative; the PI has an established record of supervising REU minority students. A special study module on "Polymers and Nanoparticles" will be prepared for students and teachers from K-12 attending the New Jersey Governor's School of Engineering and Technology and the Education and Training Institute facilitated by ERC-SOPS. The results of this work will be disseminated through peer reviewed publications, presentations at national and international meetings, and by creating a dedicated webpage for making project reports and presentations available for educational purposes. The novel simulation methods and case-study systems will be included into the new graduate course on "Nanoscale Thermodynamics and Transport" developed by PI for the IGERT curriculum. The students will benefit from industrial training and research facilities of DuPont Experimental Station. Guided by the industrial Co-PI, they will produce computer programs of practical relevance and get a hands-on experience in chromatographic experimentation.