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

Rolling two-dimensional (2D) materials into 1D nanotubes allows for greater functionality. Boron-nitride nanotubes (BNNTs) can serve as insulating 1D templates for the coaxial growth of guest nanotubes, without interfering with property characterization. However, their application as 1D templates has been greatly hindered by their poor dispersibility, inevitably resulting in the formation of thick bundles. Here we present the facile preparation of well-dispersed BNNT templates via surfactant dispersions and synthesis of 1D van der Waals heterostructures based on the BNNTs. Comprehensive microscopic analyses show the isolation of clean, high-quality BNNTs. Statistical analyses revealed that small-diameter double-walled BNNTs are highly enriched by chemical peeling of BN sidewalls through the sonication process. We further demonstrate that the isolated BNNTs can template the coaxial growth of carbon and MoS₂ nanotubes by using chemical vapor deposition. The present strategy can be applied to the synthesis of a variety of nanotubes, thereby allowing for their characterization.

Carbon and boron nanotubes as a template material for adsorption of 6-Thioguanine chemotherapeutic: a molecular dynamics and density functional approach

The interaction of 6-Thioguanine molecule, an antitumor drug with carbon nanotube and boron nitride nanotube (BNNT) is investigated using molecular dynamics simulations. Based on the obtained results, the strongest negative van der Waals interaction is found between 6-TG and BNNT among the studied nanotubes, which indicated BNNT is a better nanocarrier of the 6-TG drug than CNT within biological systems. Moreover, the adsorption and electronic properties of the 6-Thioguanine interacted with boron-nitride nanotube has been studied within the framework of density functional theory calculations. The negative binding energy values denote that there is the favorable interaction between 6-TG drug and BNNT at the studied 6-TG/BNNT complexes. Also, the amounts of the binding energies indicated that the 6-Thioguanine molecule physically interacts with the surface of BNNT. The values of electron densities and their Laplacian have been analyzed using the Bader's theory of atoms in molecules to characterize the nature of the intermolecular interactions through the topological parameters. We hope that the results of this work may provide useful information about the nature of the nanotube-drug molecule interactions and highlight the ability of these materials to be used as an adsorbent enhancing delivery of drug to cancer cells. Communicated by Ramaswamy H. Sarma.