Date of Award

Fall 2023

Document Type

Open Access Dissertation

Department

Chemical Engineering

First Advisor

Nader Taheri Qazvini

Abstract

Hybrid materials based on transition metal carbide MXene (Ti3C2Tx) nanosheets have great potential for electronic, electromagnetic interference (EMI) shielding, and environmental applications due to the unique combination of considerable electrical conductivity of 4000 to 15000 S.cm-1, abundant surface functional groups (OH, O, F, Cl), and suitable mechanical properties. However, the performance of final products depends not only on the properties of constituent components but also on the morphology of the assembly. The strong repulsive electrical double layer forces among MXene nanosheets make control over their assembly morphology and final properties challenging. To address this challenge, this dissertation focuses on applying polyelectrolytes to optimize the processing and properties/performance of MXene-based products. The results of this research provide a design map that relates the structure/property of components and processing conditions to the property/performance of MXene-based hybrids. In pursuit of the first objective, the diffusion-driven assembly method is employed to design hybrid assemblies of MXene/positively charged poly(allylamine hydrochloride) (PAH), in the forms of free-standing thin films (< 20 μm thick), fibers, and 3D porous structures. The need for the laborious layer-by-layer assembly in MXene/cationic polyelectrolyte systems is eliminated by this novel system. Furthermore, control over the internal pore sizes and shapes is enabled, allowing for the modulation of the material's electrical properties. For the second objective, this assembly method is systematically investigated to establish a correlation between the composition, processing conditions, and vi the resulting morphology and EMI shielding performance of the MXene/PAH hybrids. Through this comprehensive study, valuable insights are gained, serving as a design guide for optimizing the EMI shielding effectiveness of the MXene/polyelectrolyte hybrids. The third objective focuses on the application of polyelectrolytes in the form of microgels to enhance the processing of MXene-based products through 3D printing. This formulation enables the development of a 3D printable MXene ink with minimal solid content and controlled morphology. This advancement significantly improves the feasibility of large-scale production for customized MXene-based EMI shields, offering enhanced possibilities for tailored electromagnetic interference protection.

Rights

© 2024, Farivash Gholamirad

Download

Share

COinS