Continuum Theories Combined with Atomistic Information for Electrolyte Transport in Nanometer Channels

摘要提案标题：结合原子信息的连续介质理论在纳米通道中的电解质传输，提案编号：CTS-0625421，首席研究员：N.R.阿卢鲁，机构：伊利诺伊大学香槟分校摘要：水和离子在纳米通道和孔中的传输，称为纳米流体或电解质传输，在决定许多生物和工程设备的功能特性中起着重要作用。在这项研究中，PI建议研究基本问题，包括发展先进的连续介质理论，用于液体和电解质在受限纳米通道中的电中介传输。从智力的角度来看，PI关于流体(水)和离子在纳米通道中传输的初步研究表明，离子和水的分子性质是影响离子浓度、速度分布和其他流体特性的重要因素。具体地说，离子-离子、离子-流体、离子-表面和流体-表面相互作用对于限制在纳米通道中的流体/电解液是重要的。由于基于Poisson-Boltzmann方程和Navier-Stokes方程的连续介质理论以平均场的方式考虑了各种分子间的相互作用，因此它们不能准确地预测流体/离子特性，特别是在通道-流体界面附近。此外，限制在纳米通道中的流体会表现出反常行为，这是经典理论无法解释的。在这项研究中，PI提出了两种新的方法，即具有原子势的连续介质(CAP)和具有原子粘度的连续介质(CAV)，以克服经典理论的困难。CAP方法的基本思想是通过考虑原子盒来获得每个点的原子势，用来求解Poisson-Boltzmann方程来计算离子浓度。CAV方法的基本思想是通过在每个点上考虑一个原子盒来获得点向粘性，用来求解Navier-Stokes方程来计算体流。PI建议在几个例子上测试CAP和CAV方法，其中包括四个复杂的问题，其中观察到了异常流动行为和离子的选择性分离，而经典理论无法解释这些问题。该项目的更广泛影响包括开发先进的纳米通道中流体传输的连续介质理论，可以加速一些应用的设计和开发，包括燃料电池设备、用于化学/生物分析的混合微/纳米流体设备、通过纳米孔的核酸和蛋白质传输以及用于单分子传输和分析的仿生设备。该项目的主要努力将导致在计算纳米流体学的高度跨学科领域培养一名新的研究生。该项目的研究成果将在世界各地的档案期刊和会议上发表。作为该项目的一部分开发的基本原理和技术将构成计算纳米流体学新的跨学科课程的基础。其他计划开展的活动还包括招收妇女和少数族裔研究生、招收REU项目的本科生、将该项目的成果纳入UIUC提供的暑期学校。

Abstract Proposal Title: Continuum theories combined with atomistic information for electrolyte transportin nanometer channels, Proposal Number: CTS-0625421, Principal Investigator: N.R. Aluru, Institution: University of Illinois at Champaign-UrbanaAbstract:Water and ion transport in nanometer scale channels and pores referred to as nanofluidic orelectrolyte transport plays an important role in determining the functional characteristics of many biological and engineering devices. In this research, the PIs propose to investigate fundamental issues including the development of advanced continuum theories for electrically-mediated transport of liquids and electrolytes through confined nanochannels.From an intellectual merit perspective, the PI's preliminary studies on fluid (water) and ion transport through nanometer channels indicate that the molecular nature of the ion and water are important factors influencing the ion concentrations, velocity profiles and other fluid characteristics. Specifically, the ion-ion, ion-fluid, ion-surface and fluid-surface interactions are significant for fluids/electrolytes confined in nanochannels. As the continuum theories based on the Poisson-Boltzmann and the Navier-Stokes equations account for the various molecular interactions in a mean-field fashion, they fail to predict the fluid/ion characteristics accurately, especially near the channel-fluid interface. Moreover, fluids confined in nanochannels can exhibit anomalous behavior, which cannot be explained by the classical theory. In this research, the PI proposes to develop two new methods namely, continuum with atomistic potential (CAP) and continuum with atomistic viscosity (CAV) to overcome the difficulties with the classical theory. The CAP method, where the basic idea is to obtain an atomistic potential at each point by considering an atomistic box, is used to solve the Poisson-Boltzmann equation to compute the ion concentrations. The CAV method, where the basic idea is to obtain a point-wise viscosity by considering an atomistic box at each point, is used to solve the Navier-Stokes equations to compute the bulk flow. The PI proposes to test the CAP and CAV methods on several examples including four complicated problems where anomalous flow behavior and selective separation of ions has been observed and cannot be explained by the classical theory. The broader impacts of the project include the development of advanced continuum theories for fluid transport in nanometer channels can accelerate the design and development of a number of applications including fuel cell devices, hybrid micro/nanofluidic devices for chemical/biological analysis, nucleic acid and protein transport through nanopores and biomimetic devices for single molecule transport and analysis. The main efforts of this project will result in the education of one new graduate student in the highly interdisciplinary area of computational nanofluidics. The research results from this project will be presented in archival journals and conferences around the world. The fundamentals and techniques developed as part of this project will form the basis for a new interdisciplinary course on computational nanofluidics. Recruitment of women and minority graduate students, recruitment of undergraduate students for REU projects, incorporation of results from this project into summer schools offered at UIUC are some of the other planned activities.