Structure, Properties, and Dispersibility of OH-Functionalized Carbon Nanothreads: Implications for Nanocomposite Processing

Carbon nanothreads (NTHs) are one-dimensional materials formed from controlled compression of aromatic molecules, composed of carbon, hydrogen, and other heteroatoms present in the molecular precursors. Their postsynthesis chemical functionalization can modify and enhance some of their properties, enabling different functionalities and making them particularly suited for use in composites. In this work, we use a comprehensive set of density functional theory calculations and classical molecular dynamics simulations to analyze the structure and properties of NTHs functionalized with hydroxyl (−OH) groups, obtained through hydrolysis of remaining unsaturation along the chain of partially saturated NTHs. We explored a series of possible isomers of OH-NTHs with varied degrees of functionalization and evaluated their relative stability, intrinsic mechanical properties, potential use as fillers in reinforced polymer nanocomposites, and their dispersibility in water. While the intrinsic mechanical strength of the NTHs is not significantly altered by the presence of −OH groups, their enhanced compatibility with other polar materials and phases improves the mechanical properties of NTH-based nanocomposites and promotes proper dispersion in aqueous media. These results contribute toward the development of routes for NTH modification, aiming to improve their performance in varied technological applications.