Two-Dimensional Janus MXene Inks for Versatile Functional Coatings on Arbitrary Substrates

Abstract

Solution processing of two-dimensional nanomaterial inks guarantees efficient, straightforward fabrication of functional films, coatings, flexible devices, etc. Despite the excellent solution processibility and viscoelasticity of MXene aqueous inks, formulation of nonaqueous MXene inks with great affinity to both hydrophilic and hydrophobic substrates has proven quite challenging, limiting the practical applications of MXenes in printing/coatings on various substrates. Here, MXene surface chemistry is manipulated by asymmetrically grafting polystyrene and further concentrating the flakes into additive-free Janus MXene organic inks. The modified MXene nanosheets exhibit hydrophilicity on one side and hydrophobicity on the other. As a result, Janus MXene nanosheets ensure broad dispersibility in polar and nonpolar solvents, which in turn greatly extends the ink shelf life by slowing down the oxidation kinetics. Janus MXene sheets dispersed in toluene at room temperature remain at 90% of the initial solids after 1 month of storage. Janus surface engineering on MXene flakes guarantees the straightforward formation of uniform yet firm, large-area coatings on hydrophilic or hydrophobic substrates. These coatings demonstrate improved photothermal properties and chemical stability as well as good electromagnetic interference shielding performance. This strategy provides a simple and cost-effective way to promote the performance of MXene electronics in a variety of applications.

Three-Dimensional MXene-Based Functional Materials for Water Treatment: Preparation, Functional Tailoring, and Applications

“…On the one hand, the surface functional groups of MXenes can be used as the reaction platforms to chemically modify the MXene materials. For example, Chen et al synthesized novel Janus MXene nanosheets through manipulation of the MXene surface chemistry by asymmetrically grafting polystyrene onto the MXene nanosheets . The modified MXene nanosheets achieve hydrophilicity on one side and hydrophobicity on the other.…”

“…For example, Chen et al synthesized novel Janus MXene nanosheets through manipulation of the MXene surface chemistry by asymmetrically grafting polystyrene onto the MXene nanosheets. 85 The modified MXene nanosheets achieve hydrophilicity on one side and hydrophobicity on the other. Hence, this fascinating asymmetric wettability enables stable dispersion of the Janus MXene in various organic solvents ranging from polar to nonpolar, effectively expanding the application area of MXenes, especially in nonaqueous systems.…”

An Ultrasensitive Ti3C2Tx MXene‐based Soft Contact Lens for Continuous and Nondestructive Intraocular Pressure Monitoring

“…Abundant surface functional groups provide MXene with excellent dispersibility in water and organic solvents, allowing the use of Ti 3 C 2 T x in a multitude of sensor applications. [ 28–31 ] 4) Good biocompatibility for biosensors. Unal et al.…”

“…Abundant surface functional groups provide MXene with excellent dispersibility in water and organic solvents, allowing the use of Ti 3 C 2 T x in a multitude of sensor applications. [28][29][30][31] 4) Good biocompatibility for biosensors. Unal et al [32] demonstrated the high biocompatibility of MXenes by studying MXenes with antiviral and immunomodulatory properties against SARS-CoV-2.…”

Tuning Excitonic Properties of Monochalcogenides via Design of Janus Structures

“…Janus structures in two-dimensional (2D) materials are distinguished by their asymmetric vertical stacking with unique surface compositions, disrupting vertical symmetry and giving rise to novel physical–chemical phenomena. , For instance, Janus structures can be created by structural modifications within established classes of 2D materials, which includes transition-metal dichalcogenides (TMDs), − MXenes, monochalcogenides, or any other 2D materials comprised of a few layer thickness. The symmetry breaking in the vertical direction is a key point that gives rise to numerous applications in the scope of semiconductor optoelectronic devices with prospects for applications as sensors, photocatalytic water splitting materials, − functional coatings, and so on.…”