(410i) Fabrication of Ti3C2-Based Nanocomposites By Surface-Initiated Atom Transfer Radical Polymerization

MXenes are a class of 2-dimensional (2D) nanomaterials that possess a layered structure with an inter-gallery distance of approximately 10.04 Å in the dried state [1]. They have surface functional groups, including hydroxyl, oxygen, chlorine, and fluorine. MXenes have high hydrophilicity, high electrical conductivity, and superior antibacterial properties, surpassing those of other 2D materials such as graphene oxide [2, 3]. Polyelectrolytes and ionomers are a group of polymers that possess charged groups within their structure [4]. Due to their unique properties, these polymers have been utilized in a variety of applications, including proton-conducting membranes for fuel cells, drug delivery systems, self-healing coatings, actuators, and polymer gels. Polyelectrolytes are classified into two main groups, cationic and anionic, based on the charge of their functional groups. These charged polymers have enabled the development of multilayer films through the layer-by-layer assembly technique. Polyelectrolyte multilayers (PEMs) are a nanostructured system that is prepared by sequentially immersing a substrate into aqueous solutions of polyanions and polycations, providing precise control over the thickness of the multilayered films.

In this work, we study the fabrication of PEMs on the surface of Ti₃C₂ MXene via the use of surface-initiated atom transfer radical polymerization (SI-ATRP) and free-radical polymerization. As it is known, SI-ATRP enables us to precisely control the length of the brushes grafted onto the Ti₃C₂ surface and thus the surface properties of the modified MXenes. We compare the impacts of the polymerization methods, free-radical polymerization and SI-ATRP, by studying the effect of the length of polymer brushes on the conductivity and thermal stability of the functionalized Ti₃C₂. The successful fabrication of the nanocomposites as well as the formation of covalent bonds between the MXene functional groups and the polymers are shown using scanning electron microscopy, X-ray photoelectron spectroscopy, and X-ray diffraction.

Keywords: Ti₃C₂, surface-initiated atom transfer radical polymerization, polyelectrolyte multilayers.

References

1. Come, J., et al., Controlling the actuation properties of MXene paper electrodes upon cation intercalation. Nano Energy, 2015. 17: p. 27-35.
2. Anasori, B. and Y. Gogotsi, MXenes: Trends, growth, and future directions. Graphene and 2D Materials, 2022: p. 1-5.
3. Anasori, B., M.R. Lukatskaya, and Y. Gogotsi, 2D metal carbides and nitrides (MXenes) for energy storage. Nature Reviews Materials, 2017. 2(2): p. 1-17.
4. Eisenberg, A. and M. Rinaudo, Polyelectrolytes and ionomers. Polymer Bulletin, 1990. 24: p. 671-671.