Well-Dispersed Nanocomposites Using Covalently Modified, Multilayer, 2D Titanium Carbide (MXene) and In-Situ "click" Polymerization

Abstract

Despite the excellent mechanical and electrical performance of MXene-polymer nanocomposites, methods for producing these materials on a larger scale are limited by low-yielding, delaminated, MXene suspensions that are typically employed for their synthesis. Moreover, the hydrophilicity of MXenes restricts the production of well-dispersed nanocomposites with many polymer matrices. In this contribution, we address such limitations and report, for the first time, a simple method to covalently modify multilayered Ti3C2Tz MXenes with isocyanates, which enables their successful dispersion within a hydrophobic thiourethane matrix. The efficacy of our covalent modification was determined to yield high levels of surface grafts and suggests quantitative conversion of the oxygen-containing terminations. In situ-polymerized thiourethane "click"matrices were used to demonstrate the utility of this modification for accessing well-dispersed nanocomposites under ambient conditions. The ease of producing modified, multilayered, MXenes at scale and the availability of a wide variety of isocyanates render this method scalable and highly modular. Furthermore, the reported isocyanate treatment was found to be a valuable tool for easily quantifying the concentration of reactive (oxygen-containing) terminations on MXene surfaces.