ERI: Bonding and Filler Dispersion in One-Step, in-situ Shear Exfoliated Two-Dimensional Material-Polymer Nanocomposites and Their Application as Desalination Membranes

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公共法律117-2)。这项工程研究启动(ERI)拨款将支持制造二维(2D)材料注入聚合物纳米复合材料的研究。聚合物纳米复合材料是一类应用广泛的材料，包括航空航天结构材料、传感、能量收集、印刷电子、海水淡化和半导体工业的耗材。理想的纳米复合材料应该具有均匀的分散性和较强的填料-基质粘结性。单独制备纳米材料，然后添加到聚合物基质中，可能会受到聚合物粘附性差、杂质、团聚的影响，依赖于危险化学品的使用，并导致高生产成本。该项目研究了一种新兴的方法，即通过剪切剥离和随后的微/纳米级图案化，通过基于反馈控制的直接墨水写入(DIW)的制造技术来制备纳米材料并将其整合到聚合物本身中。通过对这些纳米复合材料中的粘合和纳米填料分散的基本了解，可以以更环保的方式制造多功能器件。这项研究的结果可以导致创新的聚合物纳米复合设备应用于海水淡化等领域，从而促进国家繁荣和福利。该项目的教育和推广部分将通过参与这一多学科研究、相关课程开发和向K-12学生演示研究概念，使未被充分代表的少数族裔学生参与STEM领域。热固性或弹性体纳米复合器件的添加制造可能会受到工具堵塞和尺寸控制不足的影响，这是由于纳米填料与聚合物的粘合和分散不良造成的。聚合物基质中层状材料的原位剪切剥离(ISE)通过在剥离的纳米材料上产生均匀分散的丰富的反应边，在无污染的环境中与单体或聚合物形成强大的键，从而显示出缓解这一挑战的前景。剥离利用大块层状材料平面之间的弱van der Waals相互作用，允许通过施加剪切力剥离到2D纳米材料(例如，从石墨到石墨烯)。该项目将利用未固化的ISE纳米复合材料，具有优化的粘度和固化动力学，用于基于热成像控制的DIW制造过程，以生成纳米涂层材料，如海水淡化膜。制作的纳米复合材料将通过流变学、显微镜、光谱分析和热成像进行分析，以阐明2D纳米膜的粘合、分散、取向和工艺参数之间的关系。纳米填料和聚合物基质之间的纳米级相互作用可以显著影响材料的性能，该项目将有助于为聚合物纳米复合材料的制造建立新的设计规则。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).This Engineering Research Initiation (ERI) grant will support research on the manufacture of two-dimensional (2D) material-infused polymer nanocomposites. Polymer nanocomposite is a class of material with applications in a wide range of areas, including structural materials for aerospace and aeronautical applications, sensing, energy harvesting, printed electronics, water desalination, and consumables for the semiconductor industry. An ideal nanocomposite should have uniform dispersion and strong filler-matrix bonding. Nanomaterials prepared separately and then added to a polymer matrix can suffer from poor polymer adhesion, impurities, agglomeration, rely on the use of hazardous chemicals, and lead to high production costs. This project investigates an emerging method of preparing and incorporating the nanomaterials within the polymer itself by shear exfoliation and subsequent micro/nanoscale patterning by feedback-controlled direct ink writing (DIW)-based manufacturing technique. Through a fundamental understanding of bonding and nanofiller dispersion within these nanocomposites, multifunctional devices can be manufactured in a more environmentally friendly manner. The outcome of this research can lead to innovative polymer nanocomposite devices utilized in fields like water desalination, and therefore advancing national prosperity and welfare. The educational and outreach component of the project will enable underrepresented minority student engagement in the STEM field through participation in this multidisciplinary research, relevant curriculum development, and demonstration of research concepts to K-12 students. Additive manufacturing of thermoset or elastomeric nanocomposite devices can suffer from tool clogging and the lack of dimensional control due to poor filler-to-polymer bonding and dispersion of nanofillers. In-situ shear exfoliation (ISE) of layered materials within the polymer matrix itself has shown promise in alleviating this challenge through the creation of uniformly dispersed abundant reactive edges on the exfoliated nanomaterial that form strong bonds with monomer or polymer in a contaminant-free atmosphere. Exfoliation utilizes the weak van der Waals interaction between planes of bulk layered materials that allow exfoliation to 2D nanomaterials (e.g., from graphite to graphene) by applying shear force. This project will utilize uncured ISE nanocomposite with optimized viscosity and curing kinetics for thermography-controlled DIW-based manufacturing process to generate nanopatterned materials such as desalination membrane. Fabricated nanocomposites will be analyzed by rheometry, microscopy, spectroscopy, and thermography to shed light on the relationship between bonding, dispersion, alignment of 2D nanofillers, and process parameters. Material properties can be significantly affected by nanoscale interaction between nanofiller and polymer matrix and this project will help establish a new design rules for the manufacture of polymer nanocomposites.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.