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 Ti 3 C 2 T z 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.

Effect of Base/Nucleophile Treatment on Interlayer Ion Intercalation, Surface Terminations, and Osmotic Swelling of Ti3C2Tz MXene Multilayers

“…In 2011, Naguib and co-workers discovered the first two-dimensional (2D) titanium carbide MXene, Ti 3 C 2 T z , and since then, nearly 30 new MXenes have been reported. − A unique combination of properties like hydrophilicity, 2D structure, chemical diversity, and metallic conductivity render MXenes an excellent candidate for a variety of applications like electromagnetic interference (EMI) shielding, − energy storage, − catalysts, − fillers in a polymer composite, − and sensors ,− among many others.…”

Dialkyl Dithiophosphate-Functionalized Ti3C2Tx MXene Nanosheets as Effective Lubricant Additives for Antiwear and Friction Reduction

“…However, Ti 3 C 2 T x MXene has obvious shortcomings such as low yield in production, delamination, and hydrophilicity, especially poor dispersibility in nonpolar organic solvents. All these hinder its practical application for tribological purposes . Therefore, various means of functionalization are employed to tailor the surface properties of Ti 3 C 2 T x MXene, including its dispersive properties.…”

A Review on MXene Synthesis, Stability, and Photocatalytic Applications

“…Postsynthesis treatments, shielding the MXene nanosheets with a protecting layer, and introducing organic functional groups on the MXene surface are proven to be effective in enabling the MXene dispersion in a wide range of organic media, averting the defect/edge-driven oxidation, and improving the performance of the MXenes in specific applications (Figure ). ,,,,− For instance, polyanionic salts (polysilicates, polyphosphates, or polyborates) that can adsorb on to positively charged MXene nanosheet edges were employed to slow down the oxidation kinetics of the MXenes for weeks in an aerated water medium (Figure (a)) . Similarly, l -ascorbate anions were also reported to enhance the oxidation stability of the MXenes in both the aqueous dispersion and dried powder/film forms .…”