Recent Advances in the Theory of Non-carbon Nanotubes

Abstract

Our classical understanding of hollow inorganic nanostructures, established by Linus Pauling in 1930 and recommenced by Reshef Tenne 25 years ago, has undergone a revolution in recent years, owing to the rapid growth of computational facilities and to the new experimental and theoretical techniques looking into the origin of properties at an atomistic level. This overview gathers both the basic concepts and the most recent results from the diverse and broad field of computational materials science devoted to non-carbon nanotubes. A special emphasis is given to the stability, electronic, mechanical and capillary properties obtained at an interface between fundamental theoretical research and engineering of new advanced materials like commercially available nanotubes of layered sulfides, aluminosilicates and boron nitride.

Imogolite: Curvature‐Induced Hospitality for Trivalent Dopants

“…[48] Therefore, the same classification for labeling these tubes was used as for nanotubes rolled up from hexagonal compounds (graphite, h-BN, metal dichalcogenides, etc.). [7] Depending on the rolling direction B in the 2D lattice B ¼ na 1 þ ma 2 (a 1 , a 2 are lattice vectors of the hexagonal lattice, Figure 1), three classes of nanotubes can be constructed: zigzag (n,0), armchair (n,n), and "chiral" (n,m) nanotubes with n 6 ¼ m. The main attention was focused on the chirality (12,0) as the chirality of natural and synthetic imogolites in the majority of earlier reports, which unit cell consists of 336 atoms. To perceive the permanence of registered phenomena, the models of (8,0) and (14,0) imogolite nanotubes were studied, containing 224 and 392 atoms in the unit cells, respectively.…”

“…Two kinds of hydroxyl groups offer the interesting applications of imogolite as proton conductor, ion retention medium, and a backbone of channel devices. As a consequence, theoretical investigations of imogolite nanotubes have been devoted to a more profound study of interplay between their structure and formation mechanism, thermodynamic stability, adhesive and mechanical properties, using all levels of theory-phenomenological, molecular mechanics, and quantum-chemical descriptions (see reviews [7,[16][17][18]). Departed from consideration of perfect imogolite nanotubes, the modern theoretical research focuses on their intrinsic and extrinsic defects as progenitors of peculiar properties and as elements required for targeted functionalization of imogolite.…”

“…The functional description of the stability for such nanotubes implies inclusion of the difference in surface tensions between the external and internal surfaces of the tube wall apart of the strain energy. [7,8] As a spontaneous rolling up is possible, the true morphology of natural nanotubes is often represented as a scroll and their walls are always composed of dozens layers with the only single exception as imogolite.…”

Surfactant-Assisted Isolation of Small-Diameter Boron-Nitride Nanotubes for Molding One-Dimensional van der Waals Heterostructures

“…This has been especially observed in carbon nanotubes (CNTs), which exhibit a wealth of intriguing properties depending upon their structural chirality . Many candidate nanotubes have been extensively screened for this transformation in theoretical studies. − Despite this growing interest, however, the structural and electronic properties of these candidates are not well-understood as compared with CNTs, due to the poor controllability over their constitution. Critically, isolation of their single walls is needed to measure electronic properties related to their chirality.…”