Radical Addition of Xanthates on Carbon Nanotubes as an Efficient Covalent Functionalization Method

Covalent functionalization of 1D and 2D sp2-carbon nanoallotropes - twelve years of progress (2011-2023)

Carbon nanoallotropes have attracted significant attention in the field of materials science due to their unique combination of physicochemical and biological properties, with numerous applications. One-dimensional (1D) and two-dimensional (2D) sp2-carbon nanoallotropes, such as carbon nanohorns (CNHs), carbon nanotubes (CNTs), and graphene, have emerged as prominent candidates for a variety of technological advancements. To fully exploit their exceptional characteristics, the covalent functionalization of these nanostructures may alleviate the problems with the processing and final performance. This route of the carbon nanoallotrope functionalization is based on a covalent attachment of functional groups or molecules (via linkers of various strengths) to their surfaces, enabling precise control over physical, chemical, biological, and electronic properties. Such an approach opens up new avenues for tailoring the nanoallotrope characteristics, such as solubility/dispersibility, reactivity, and interactions with other materials. Over more than the last decade, significant progress has been made in the covalent functionalization of both 1D and 2D sp2-carbon nanoallotropes, paving the way for diverse applications in the nanoelectronics, energy storage, sensing, and biomedical fields. In this comprehensive review, we provide state-of-the-art advancements and achievements in the covalent functionalization of 1D and 2D sp2-carbon nanoallotropes during the past dozen years. We aim to highlight the key strategies, methodologies, and breakthroughs that have significantly contributed to this field. Eventually, we discuss the implications of those advancements and explore the opportunities for future research and applications.

Covalent Grafting of BPin functions on Carbon Nanotubes and Chan-Lam-Evans Post-Functionalization

The chemical functionalization of carbon nanotubes is often a prerequisite prior to their use in various applications. The covalent grafting of 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (BPin) functional groups directly on the surface of multi- and single-walled carbon nanotubes, activated by nucleophilic addition of nBuLi, was carried out. Thermogravimetric analysis (TGA) coupled with mass spectrometry, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ions mass spectrometry (ToF-SIMS) confirmed the efficiency of this methodology and proved the integrity and covalent grafting of the BPin functional groups. These groups were further reacted with various nucleophiles in the presence of a copper(II) source in the conditions of the aerobic Chan-Lam-Evans coupling. The resulting materials were characterized by TGA, XPS and ToF-SIMS. This route is efficient, reliable and among the scarce reactions that enable the direct grafting of heteroatoms at carbonaceous material surfaces.

Carbon nanotubes: a novel material for multifaceted applications in human healthcare

Remarkable advances achieved in modern material technology, especially in device fabrication, have facilitated diverse materials to expand the list of their application fields.

Designing multimodal carbon nanotubes by covalent multi-functionalization

Carbon nanotubes (CNTs) are a unique tool in nanotechnology owing to their exceptional properties that offer a variety of opportunities for applications in different fields. Nevertheless, their low dispersibility in organic solvents and in aqueous media hampers their development. The functionalization of their surface allows overcoming this issue, while exploiting and tuning their properties. Thanks to their high specific surface area, multi-functionalization strategies give the possibility to conjugate several copies of different molecules to endow the nanotubes with multiple functionalities. In this context, this review wishes to focus on the preparation of multimodal CNTs designed by covalent multi-functionalization. More specifically, we describe the different approaches that have been developed to prepare multi-functionalized CNTs through double and triple covalent functionalization of the nanotube framework. We also emphasize the strategies used to control the derivatization of multi-functionalized CNTs with molecules of interest mainly via sequential or simultaneous methodologies.

Brominated single walled carbon nanotubes as versatile precursors for covalent sidewall functionalization

Brominated SWCNTs serve as versatile building blocks for the facile generation of sidewall functionalized SWCNT derivatives.