Nonpolar Organic Dispersion of 2D Ti₃C₂T_<i>x</i> MXene Flakes <i>via</i> Simultaneous Interfacial Chemical Grafting and Phase Transfer Method

Abstract

Herein, we demonstrate a simple and versatile way for preparing stable Ti₃C₂T_<i>x</i> MXene dispersions in nonpolar organic solvents through a simultaneous interfacial chemical grafting reaction and phase transfer method. Alkylphosphonic acid ligands were chemically grafted on the hydroxyl terminal groups of Ti₃C₂T_<i>x</i> flakes at the liquid-liquid interface between water and water-immiscible organic medium to form a covalent Ti-O-P bond <i>via</i> interfacial nucleophilic addition and sequential condensation reaction at room temperature; the surface-functionalized Ti₃C₂T_<i>x</i> flakes concurrently migrated from the aqueous phase to the organic phase. Unlike conventional surface chemical modification methods that require many complex and tedious steps, this is a simple and easy process for fabricating a Ti₃C₂T_<i>x</i> organic dispersion in various organic solvents, from highly polar to nonpolar. The nonpolar Ti₃C₂T_<i>x</i> dispersion in chloroform also exhibits strong oxidation resistance and stable long-term storage. This approach provides an opportunity for preparing MXene nanocomposites with nonpolar polymeric matrices that are soluble in organic media for future applications such as stretchable electrode.