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。这项工程研究启动（ERI）资助将支持二维（2D）材料注入聚合物纳米复合材料的制造研究。聚合物纳米复合材料是一类具有广泛应用领域的材料，包括用于航空航天应用的结构材料、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具有均匀的分散和强的填料-基体结合。单独制备的纳米材料，然后添加到聚合物基体中，可能存在聚合物附着力差、杂质、团聚、依赖危险化学品的使用以及导致生产成本高的问题。该项目研究了一种新兴的方法，通过剪切剥离和随后的微/纳米尺度图案，通过反馈控制的直接墨水书写（DIW）为基础的制造技术，将纳米材料制备和整合到聚合物内部。通过对这些纳米复合材料中的键合和纳米填料分散的基本理解，多功能器件可以以更环保的方式制造。这项研究的结果可以导致创新的聚合物纳米复合器件应用于海水淡化等领域，从而促进国家的繁荣和福祉。该项目的教育和推广部分将通过参与这项多学科研究、相关课程开发以及向K-12学生展示研究概念，使未被充分代表的少数民族学生参与STEM领域。热固性或弹性体纳米复合材料器件的增材制造可能会受到工具堵塞和缺乏尺寸控制的影响，这是由于填料与聚合物的粘合不良和纳米填料的分散。聚合物基体内部层状材料的原位剪切剥落（ISE）有望缓解这一挑战，通过在剥落的纳米材料上创造均匀分散的丰富的反应性边缘，在无污染的大气中与单体或聚合物形成牢固的键合。剥落利用体层状材料平面之间的弱范德华相互作用，通过施加剪切力使二维纳米材料（例如，从石墨到石墨烯）剥落。该项目将利用未固化的ISE纳米复合材料，优化粘度和固化动力学，用于热成像控制的基于diw的制造过程，以生产纳米图案材料，如脱盐膜。制备的纳米复合材料将通过流变学、显微镜、光谱学和热成像来分析，以阐明2D纳米填料的键合、分散、排列和工艺参数之间的关系。纳米填料与聚合物基体之间的相互作用会显著影响材料的性能，本研究将为聚合物纳米复合材料的制造建立新的设计规则。该奖项反映了美国国家科学基金会的法定使命，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.