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

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。该工程研究启动（ERI）拨款将支持二维（2D）材料注入聚合物纳米复合材料制造的研究。聚合物纳米复合材料是一类应用广泛的材料，包括用于航空航天和航空应用的结构材料、传感、能量收集、印刷电子、水脱盐和半导体工业的消耗品。理想的纳米复合材料应具有均匀的分散性和强的填料-基体结合。单独制备然后添加到聚合物基质中的纳米材料可能会遭受聚合物粘附性差、杂质、团聚、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，通过剪切剥离和随后的微/纳米级图案化，通过反馈控制的直接墨水写入（DIW）为基础的制造技术，制备和纳入聚合物本身的纳米材料。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理解，可以以更环保的方式制造多功能设备。这项研究的结果可以导致创新的聚合物纳米复合材料设备用于水淡化等领域，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多学科研究，相关课程开发以及向K-12学生展示研究概念，使代表性不足的少数民族学生能够参与STEM领域。热固性或弹性体纳米复合材料装置的增材制造可能由于填料与聚合物的粘合和纳米填料的分散差而遭受工具堵塞和缺乏尺寸控制。聚合物基质本身内的层状材料的原位剪切剥离（伊势）已经显示出通过在剥离的纳米材料上产生均匀分散的丰富的反应性边缘来缓解这一挑战的希望，所述反应性边缘在无污染的气氛中与单体或聚合物形成强键。剥离利用块状层状材料的平面之间的弱货车范德华相互作用，其允许剥离成2D纳米材料（例如，从石墨到石墨烯）。该项目将利用具有优化粘度和固化动力学的未固化伊势纳米复合材料，用于基于热成像控制的DIW制造工艺，以生成纳米图案化材料，如脱盐膜。制造的纳米复合材料将通过流变仪，显微镜，光谱学和热成像进行分析，以揭示2D纳米填料的粘合，分散，对齐和工艺参数之间的关系。纳米填料和聚合物基体之间的纳米级相互作用可以显著影响材料性能，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知识价值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.