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Quantification of hexagonal boron nitride impurities in boron nitride nanotubes <i>via</i> FTIR spectroscopy
摘要： Preparation of high-quality boron nitride nanotubes (BNNTs) from commercially available stock is critical for eventual industry adoption and to perform comprehensive experimental studies of BNNTs. Separation of h-BN and BNNTs is a significant challenge, and equally so, quantification of h-BN content in mixed samples is a major challenge due to their nearly identical properties. This work introduces a simple method of quantifying h-BN content in BNNTs based on FTIR analysis. Quantification is achieved by 'spiking' a BNNT sample with pure nanoscale h-BN as an internal standard. To demonstrate the efficacy of the quantification technique two BNNT enrichment methods, surfactant wrapping and centrifugation, and a novel sonication-assisted isovolumetric filtration are introduced. FTIR spectra of enriched samples show clear trends throughout the processes. We propose and demonstrate that FTIR peak ratios of the Transverse and Buckling modes of mixed h-BN/BNNT samples can be used to calibrate and quantify h-BN content in any BNNT sample. Hopefully, this method enables as-received BNNTs to be quantifiably enriched from low purity commercial feedstocks, enabling future development and study of BNNTs and related technology.
关键词： FTIR spectroscopy,Boron nitride nanotubes,hexagonal boron nitride,enrichment methods,quantification
更新于2025-11-14 15:13:28
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Single-Walled boron nitride nanotubes interaction with nickel, titanium, palladium, and gold metal atoms- A first-principles study
摘要： Ab initio calculations based on density functional theory was carried out to study the electronic properties of (3,3), (4,2), (5,2) and (6,0) boron nitride nanotubes when interacting with nickel, titanium, palladium and gold metal atoms. These interactions occurred via adsorption, intercalation, nitrogen substitutional doping and boron substitutional doping. The wide band gaps intrinsic to the pristine boron nitride nanotubes were successfully tuned upon interaction with the metal atoms irrespective of the type of interactions. However, for most of the interactions that occurred via intercalation and nitrogen substitutional doping, the boron nitride nanotube was found to possess semi-metallic properties. More states were added in the density of states upon interaction in which the d orbital of the transition metal atoms was found to be the major contributor to the increase in density of states.
关键词： Transition metals,Fermi energy,Density functional theory,Band gap,Boron nitride nanotubes
更新于2025-09-19 17:13:59
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Dual growth mode of boron nitride nanotubes in high temperature pressure laser ablation
摘要： The morphological analysis of the end of boron nitride nanotubes (BNNTs) using high-resolution transmission electron microscopy (HR-TEM) can provide valuable insight into the growth mechanism in high temperature pressure (HTP) laser ablation where the best quality of BNNT materials can be obtained so far. Two growth modes of BNNT coexisting during the synthesis process have been proposed based on HR-TEM observation and length analysis. One is the root growth mode, in which boron nitride (BN) species formed via the surface interaction between surrounding N2 molecules and boron nanodroplets incorporate into the tubular structure. Another mode called open-end growth mode means the prolongation of tube growth from the exposed BN edge surrounding the surface of boron nanodroplets which is constructed by the heterogeneous nucleation of absorbed BN radicals from the gas plume. The statistical data, the proportions of end structures and the length of BNNTs, could be fitted to two growth modes, and the open-end growth mode is found to be especially effective in producing longer nanotubes with a higher growth rate. The scientific understanding of the growth mechanism is believed to provide the control for optimized production of BNNTs.
关键词： growth mechanism,high temperature pressure laser ablation,open-end growth mode,root growth mode,boron nitride nanotubes,HR-TEM
更新于2025-09-12 10:27:22
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pH-Controlled fluorescence switching in water-dispersed polymer brushes grafted to modified boron nitride nanotubes for cellular imaging
摘要： pH-Switchable, fluorescent, hybrid, water-dispersible nanomaterials based on boron nitride nanotubes (BNNTs) and grafted copolymer brushes (poly(acrylic acid-co-fluorescein acrylate) – P(AA-co-FA)) were successfully fabricated in a two-step process. The functionalization of BNNTs was confirmed by spectroscopic, gravimetric and imaging techniques. In contrast to “pure” BNNTs, P(AA-co-FA)-functionalized BNNTs demonstrate intense green fluorescence emission at 520 nm. Under neutral or alkaline pH values, P(AA-co-FA)-functionalized BNNTs are highly emissive in contrast to acidic pH conditions where the fluorescent intensity is absent or low. No increase in the absorption was observed when the suspension pH was increased from 7 to 10. The functionalized BNNTs are easily taken up by human normal prostate epithelium (PNT1A) and human prostate cancer cell lines (DU145) and are suitable for further evaluation in cellular imaging applications.
关键词： pH switching,surface modification,cellular imaging,fluorescence,boron nitride nanotubes,polymer brushes
更新于2025-09-12 10:27:22
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Boron Nitride Nanotubes in Nanomedicine || Optical properties of boron nitride nanotubes: potential exploitation in nanomedicine
摘要： Nanotechnology is the ability and the art of exploiting nanometer-scale control on the size and the shape of a system, in order to obtain novel physicochemical properties. Chemical reactivity, optical response, and interactions with cells and tissues of nanotailored materials can be remarkably different from those of the bulk counterpart. The application of this flexibility and of the enormous potential that it brings along to the treatment, prevention, or diagnosis of diseases—that is, nanomedicine—is a novel opportunity that in spite of its young age is already representing a market valued at almost 80 billion USD in 2012 [1], with hundreds of nanomedicines and nanoformulations which are either approved or under clinical evaluation [2]. In the class of nanomaterials, boron nitride nanotubes (BNNTs) possess unique characteristics that make them particularly appealing. BNNTs are structural equivalents of carbon nanotubes (CNTs) with boron and nitrogen atoms replacing the carbon atoms of CNTs, and can be thought as a rolled sheet of hexagonal BN (h-BN) as depicted in Fig. 9.1a, b, and d. Despite their structural similarity with CNTs, they are comparable or superior to the latter in terms of several technologically relevant properties such as a thermal conductivity (at least in isotopically pure tubes) [3], thermal [4] and chemical [5] stability, piezoelectricity [6], and mechanical strength [7]. These peculiar advantages stem from the significant ionic component of the covalent bonds between B and N atoms.
关键词： Boron Nitride Nanotubes,Optical Properties,Nanotechnology,Nanomedicine
更新于2025-09-11 14:15:04
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Boron Nitride Nanotubes in Nanomedicine || Boron nitride nanotube films: preparation, properties, and implications for biology?applications
摘要： Boron nitride nanotubes (BNNTs) share the same structure as carbon nanotubes (CNTs), but have boron and nitrogen atoms sitting close to each other. Some properties of BNNTs are similar to their carbon counterparts, such as mechanical strength, thermal conductivity, and wettability. However, there are also many differences between them. BNNTs are insulators with a wide bandgap of about 6 eV, which is not sensitive to their diameter and chirality. Compared to CNTs, BNNTs are more thermally stable in air and, therefore, better candidates as fillers in metal/ceramic composites, field emitters, and thermal management materials at high temperatures. BNNTs show strong light emission at ～227 nm in the deep ultraviolet (DUV) region and are useful in optoelectronic, medical, data storage, and lithography applications. Isotopic 10BNNTs not only exhibit greatly improved thermal conductivity superior to that of CNTs, but also provide radiation shielding. Due to the electric polarization, BNNTs are piezoelectric and suitable for electromechanical devices on the nanoscale.
关键词： biology applications,Boron nitride nanotubes,properties,BNNT films,preparation
更新于2025-09-11 14:15:04
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Influence of Defects in Boron Nitride Nanotubes in the Adsorption of Molecules. Insights from B3LYP-D2* Periodic Simulations
摘要： The adsorption of H2O, NH3 and HCOOH as polar molecules and C6H6 and CH4 as non-polar ones on a series of zig-zag (6,0) single-walled boron nitride nanotubes (BNNTs) both being defect-free (P_BNNT) and containing defects at the nanotube walls has been studied by means of B3LYP-D2* periodic calculations. We focused on defects derived from monovacancies of B (N-rich_BNNT) and N (B-rich_BNNT) atoms and also on Stone-Wales defects (SW_BNNT). The adsorption of polar molecules with defective BNNTs is generally based on dative interactions and H-bonding, and their adsorption energies strongly depend on the type of BNNT. N-rich_BNNT is the most reactive nanotube towards adsorption of polar molecules, as in all cases deprotonation of the polar molecules is spontaneously given upon adsorption. The strength in the adsorption energies is followed by B-rich_BNNT, SW_BNNT and P_BNNT. Adsorption of non-polar molecules is mainly dictated by dispersion interactions, and, accordingly, the adsorption energies are almost constant for a given molecule irrespective of the type of nanotube.
关键词： adsorption,vacancies,periodic simulations,boron nitride nanotubes,DFT,Stone-Wales defect
更新于2025-09-09 09:28:46
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[IEEE 2018 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD) - Austin, TX, USA (2018.9.24-2018.9.26)] 2018 International Conference on Simulation of Semiconductor Processes and Devices (SISPAD) - A Compact Model of Drift and Diffusion Memristor Applied in Neuron Circuits Design
摘要： A compact model of memristor for unifying two switch characteristics, drift and diffusion has been proposed, based on the ion dynamic transport theory at the oxide interface layer. The model is verified by measured data in different oxide-material-based drift/diffusion memristors, and well fits DC/AC characteristics of both devices, under parameter variations and temperature evolution. Moreover, the applications of this model in neuron circuits design are shown.
关键词： adsorption effect,boron nitride nanotubes,first-principles calculations,small molecule
更新于2025-09-09 09:28:46