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

The University Of Texas Rio Grande Valley, Edinburg TX

Investigators

Abstract

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.