Ionic Polyimides: Design, Synthesis, Characterization and Modeling of a Versatile Material Platform for Membrane Separations

提案号：1605411，PI: Bara, j.e标题：工程先进聚合物材料作为高效气体分离膜气体分离，如空气分离（氧气/氮气），天然气中的二氧化碳/甲烷和合成气（氢气/一氧化碳）是工业化学过程的重要组成部分，这些过程生产了许多对国家经济和福祉至关重要的最重要的经济材料。传统上，这些分离是使用完善的，但能源密集型的操作，如蒸馏或吸收和汽提过程进行的。使用聚合物膜提供了一种替代方法，以节能的方式进行这些分离，并具有较低的投资成本。然而，仍然存在阻碍聚合物膜技术广泛应用的差距。该项目将提供必要的基础研究，以了解聚合物结构和化学对性能属性的作用，如提高吞吐量，提高产品纯度和延长膜寿命。通过使用合成化学、聚合物工程和计算机建模，该项目将把来自不同类别的聚合物材料的最重要的结构元素结合到独特的、前所未有的聚合物结构中，这些结构具有每种材料的理想性能，同时旨在消除或最小化各自的局限性。在这个项目中正在开发的新聚合物的研究将打开一个巨大的新材料库，用于各种工程应用。此外，正在使用的计算机模拟将推进研究人员在分子水平上可视化和理解聚合物材料的方法。该项目将培养研究生和本科生在协同实验和计算环境中工作，这是21世纪研究的一个重要方面。该项目还将涉及以3d打印和智能手机移动应用程序为中心的推广活动，通过使用他们熟悉的工具和游戏，向更广泛的学生介绍工程概念。本研究的关键目标是通过实验和计算了解离子聚酰亚胺聚合物膜的结构-性能-性能关系，用于气体分离。这项工作将评估离子聚酰亚胺在与能源生产和温室气体排放相关的几个关键气体对中的效用。通过结合聚酰亚胺、离子液体、固有微孔聚合物和金属有机框架中使用的配体的元素，离子聚酰亚胺的设计策略是完全未知的，并提供了控制和改善聚合物性能的能力，如基于库仑吸引驱动的非共价超分子组装的分数自由体积（FFV），这也可能有助于减缓/阻止聚合物老化。随着独特的分子水平模拟模型的发展，对离子聚酰亚胺性能的基本理解将得到加强。三种不同级别的模型分辨率将被采用（量子力学，分子动力学和动力学蒙特卡罗），以建立一个具有明确的气体/聚合物/气体界面的综合膜模型。这将使建模领域向实验系统的真实表示迈出重要的一步，允许描述梯度驱动的流动，类似于与实际工业气体分离过程相关的压降环境。该项目的成功将转化为构建纳米结构聚合物膜的能力的重大进步，以实现更低的能量和成本分离。此外，基于众所周知的传统聚酰亚胺作为高性能聚合物的广泛用途，离子聚酰亚胺可能是许多其他应用所需要的。

Proposal Number: 1605411, PI: Bara, J.E.Title: Engineering Advanced Polymer Materials as Membranes for Energy Efficient Gas SeparationsGas separations such as air separation (oxygen/nitrogen), carbon dioxide/methane in natural gas, and syngas (hydrogen/carbon monoxide) are important components of industrial chemical processes that produce many of the most economically important materials vital for the Nation's economy and well being. Traditionally, these separations have been carried out using well-established, but energy intensive operations such as distillation or absorption and stripping processes. Use of polymer membranes offers an alternative approach to perform these separations in an energy efficient manner and with lower investment cost. However, gaps still exist that block the wider use of polymer membranes technologies. This project will provide the fundamental research that is needed to understand the role of polymer structure and chemistry on performance attributes such as enhanced throughput, increased product purity and long membrane lifetimes. Through the use of synthetic chemistry, polymer engineering, and computer modeling, this project will combine the most important structural elements from the separate classes of polymer materials into unique and unprecedented polymer structures that possess the desirable properties of each individual material while aiming to eliminate or minimize the respective limitations. Investigation of the new polymers being developed in this project will open a vast new library of materials for use in a variety of engineering applications. Furthermore, the computer simulations being employed will advance the ways in which researchers visualize and understand polymeric materials at the molecular level. This project will train graduate and undergraduate students to work in a synergistic experimental and computational environment, an important aspect of 21st century research. This project will also involve outreach activities centered around 3-D printing and mobile apps for smartphones to inform a wider range of students on concepts in engineering using tools and games that they are familiar with.The key objectives of this research are to experimentally and computationally understand the structure-property-performance relationships underlying ionic polyimide polymer membranes for gas separations. This work will assess the utility of ionic polyimides across several key gas pairs related to energy production and greenhouse gas emissions. By combining elements of polyimides, ionic liquids, polymers of intrinsic microporosity and ligands used in metal organic frameworks, the ionic polyimide design strategy is completely unexplored and provides the ability to control and improve polymer properties such as fractional free volume (FFV) based on non-covalent supramolecular assembly driven by coulombic attractions, which may also assist in slowing/stopping polymer aging. The fundamental understanding of ionic polyimide performance will be enhanced with the development of unique molecular-level simulation models. Three different levels of model resolution will be employed (quantum mechanics, molecular dynamics, and kinetic Monte Carlo) in order to build a comprehensive membrane model with explicit gas/polymer/gas interfaces. This will move the modeling field a significant step closer towards realistic representations of the experimental systems, allowing the description of gradient-driven flow, similar to the pressure-drop environment associated with actual industrial gas separation processes. The success of this project will translate to major advancements in the ability to build nanostructured polymer membranes, for lower energy and cost separations. Furthermore, ionic polyimides are likely to be desirable for many other applications based on the well-known broad utility of conventional polyimides as high-performance polymers.