Issue 32, 2023

Modification of Ti3C2Tx MXene with hyperbranched polyethylene ionomers: stable dispersions in nonpolar/low-polarity organic solvents, oxidation protection, and potential application in supercapacitors

Abstract

MXenes have attracted enormous research interest due to their 2D structure and advantageous properties. However, they show low/poor dispersibility in a wide variety of organic solvents, particularly nonpolar or low-polarity solvents, and tend to get oxidized in the presence of oxygen and water during storage, handling, delamination, and applications under ambient conditions. In the present study, we report a simple yet convenient noncovalent modification strategy with the use of hyperbranched polyethylene ionomers containing quaternary ammonium ions to prepare stable, highly concentrated Ti3C2Tx MXene dispersions in various nonpolar and low-polarity organic solvents. Constructed with nonpolar hydrophobic hyperbranched polyethylene backbones, the ionomers contain covalently tethered quaternary ammonium cations, which can bind tightly onto the negatively charged Ti3C2Tx MXene surface by ionic interactions. Simple mixing provides the ionomer-modified MXenes (I-MXenes) with the hyperbranched polyethylene ionomers efficiently intercalated within the MXene sheets. Accordingly, the interlayer spacing of Ti3C2Tx MXene can be expanded to more than 5 nm with an increase of at least 400% compared to the original spacing of 1 nm. The surface modification effectively adjusts the surface properties of MXene sheets and facilitates their compatibility with various nonpolar or low-polarity organic media. The resulting modified MXenes are readily stably dispersible in a broad range of nonpolar or low-polarity organic solvents, including tetrahydrofuran (THF), chloroform, xylene, and toluene, at high concentrations (as high as 30 mg mL−1 in THF) after simple sonication. Meanwhile, the modification also markedly improves the oxidation stability of MXene sheets due to the presence of the tightly surface-bound hydrophobic hyperbranched polyethylene protecting layer. In contrast to the easy oxidation of unmodified MXenes, the ionomer-modified MXenes are stable in air-saturated water even for weeks with no/minimum oxidation. Subsequently, a symmetrical two-electrode supercapacitor made from an I-MXene suspension in THF exhibits a capacitance of 220 F g−1 at a scan rate of 2 mV s−1. This strategy thus facilitates the processing of MXenes in the form of organic dispersions and greatly expands their opportunities for different applications in various areas, particularly in electrochemical energy storage devices.

Graphical abstract: Modification of Ti3C2Tx MXene with hyperbranched polyethylene ionomers: stable dispersions in nonpolar/low-polarity organic solvents, oxidation protection, and potential application in supercapacitors

Supplementary files

Article information

Article type
Paper
Submitted
17 May 2023
Accepted
07 Jul 2023
First published
07 Jul 2023

J. Mater. Chem. A, 2023,11, 17167-17187

Modification of Ti3C2Tx MXene with hyperbranched polyethylene ionomers: stable dispersions in nonpolar/low-polarity organic solvents, oxidation protection, and potential application in supercapacitors

B. Raisi, L. Huang and Z. Ye, J. Mater. Chem. A, 2023, 11, 17167 DOI: 10.1039/D3TA02936K

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements