Pure BN Research Articles

Evaluation of Drug Delivery Systems Based on Host–guest Interactions Between Pure/Metal‐doped BN Nanotubes with Oteracil and Potassium Oteracil Anticancer Drugs

AbstractThe aim of this project is to investigate host–guest complexes based on pure and doped‐BN nanotubes for the treatment of gastric and gastrointestinal cancer. Therefore, in this work, the host–guest complexes obtained from the interaction of pure boron nitride nanotubes (BNNTs) as well as Al and Ga‐doped BN nanotubes with the anticancer drugs of Oteracil (OT) and potassium oteracil (OTP) were investigated in the gas phase and water solvent. All calculations were performed at the M06‐2X/6–31G(d) level of theory. Interaction energies, structural parameters, topological properties as well as RDG, ELF, and CCD analyses were used to assess the strength of interactions in the complexes. The results show that the doped‐BN nanotubes have stronger interactions with OT and OTP drugs. Adsorption energies (ΔEads) reveal that the adsorption tendency of drugs on nanotubes is in the order of BN(Ga) > BN(Al) > pure‐BN. The electronic properties of pure and doped‐BN nanotubes were investigated and compared before and after the adsorption process. The quantum molecular descriptors were used to investigate the reactivity of pure and doped‐BN nanotubes to drugs. The energy gap (Eg) was dramatically changed when the dopant atoms were added to the BN nanotube. Therefore, the impurity can improve the reactivity of the pure BN nanotube. The type of adsorption in pure and doped‐BN nanotubes can be physical. Increasing temperature reduces recovery time. Analysis of natural bond orbital (NBO), molecular electrostatic potential surface maps (MESP), and the (RDG) were performed to evaluate the nature of the drug/nanotube intermolecular interactions. Generally, the tendency of Al and Ga‐doped nanotubes to absorb OT and OTP drugs is higher than that of pure nanotubes. This study can provide insights into innovation in the design of drug delivery systems.

Experimental and theoretical insights into enhanced hydrogen uptake by H2-activated BNOC nanomaterials

Advanced hydrogen storage systems are needed to develop the next generation of portable batteries and vehicles. In this work, effect of oxygen and carbon vacancies in oxygen- and carbon-substituted hexagonal boron nitride (h-BN) nanocrystallites on hydrogen adsorption (Had) is investigated for the first time. For this purpose, BNOC nanomaterials containing 8–13 at% O and 3–6 at% C were synthesized from melamine-boric acid precursors in an ammonia-hydrogen atmosphere at moderate temperatures. The hydrogen-binding properties of h-BN-based nanomaterials strongly depend on the type of defects and the dopant present; therefore, hydrogen was used in the synthesis as an activator, creating active centers by removing oxygen and carbon. The resulting BNOC nanomaterials are characterized by low crystallinity, with crystallite sizes less than 2 nm. The best sample with a specific surface area of 1405.1 m2×g−1, a specific pore volume of 0.779 cm3×g−1, and a micropore volume of 0.517 cm3×g−1 showed Had capacity of 5.2 wt% at T = 77.35 K and a pressure of 100 kPa. The pressed BNOC nanomaterials also exhibited decent volumetric H2 uptake in the range of 16.7–18.7 g × L−1 for pellet densities in the range of 0.59–0.74 g × cm−3. Density functional theory (DFT) calculations showed that Had up to 2.3 wt% at T = 77 K is only possible on pure BN, “armchair” carbon defects, and oxygen defects. Had up to 4.0 wt% is achievable on “zigzag” carbon defects at T < 70 K; above this temperature, hydrogen desorption occurs. Had from ∼3 to 5.3 wt% at T = 77 K is thermodynamically favorable only for oxygen defects, above 5.3 wt%, the adsorption energy becomes positive, indicating the limit of hydrogen sorption. X-ray photoelectron spectroscopy (XPS) analysis suggests that the superior H2 uptake of BNOC nanomaterials may be due to the hydrogen treatment-induced formation of active sites, such as oxygen and carbon vacancies. The obtained results not only demonstrate the promise of BNOC nanomaterials for hydrogen storage but also show the possibility of controlling structural defects to increase hydrogen uptake. Creating active sites through restructuring different types of vacancies may be a new strategy to improving hydrogen uptake.

Mechanical properties of C3N-BN hybrid nanosheets: Insights from molecular dynamics simulations

Molecular dynamics simulations have been utilized to explore the mechanical properties of the C3N-BN hybrid nanosheet across varying temperatures and strain rates, as well as in the presence of two different types of defects: circular holes and single vacancy atoms introduced into the hybrid structure. The findings revealed that the hybrid material shows intermediate mechanical properties compared to pure C3N and BN. The mechanical characterization of the hybrid suggests that variations in mechanical parameters remain relatively stable across different strain rates. However, temperature changes significantly affect the mechanical properties of the hybrid, with the highest failure stress recorded as 123.70 (GPa), failure strain of 21.57 %, and Young's Modulus of 747.25 (GPa) at 100 Kelvin. Expanding the hole radius decreases failure stress by approximately 76 %, 56 %, and 82 % when holes are exerted in the interface, BN, and CN sides of the hybrid, respectively, and reduces Young's modulus by about 65 %, 67 %, and 66 %. Introducing circular holes within the BN domain enhanced the hybrid structure's strength and resilience, demonstrating BN's superiority over C3N. Therefore, placing holes in the BN region is recommended for achieving superior mechanical properties in such structures. The introduction of single-atom vacancies revealed that carbon vacancies induced a far more significant mechanical strength reduction than vacancies of other atoms.

Structures of Ni-doped Bn (n = 1–13) clusters: A computational study

The structural and stability properties of Ni-doped boron clusters (NiBn with n = 1–13) are investigated by the SCG (systematic growth algorithm) method in combination with density functional theory (DFT) calculations. The results show that the Ni dopant adopt peripheral and top positions in the lowest-energy structures of NiBn clusters. Planar and quasi-planar structures are found for n = 3–6, 10 and 11 while three-dimensional for n = 7–8, 12 and 13. The NiBn clusters show slightly less binding energy compared to the pure Bn clusters. The relative stability of the clusters is rationalized through energetic parameters such as ionization potential, electron affinity, second order energy difference and HOMO–LUMO gap. The results show that NiB12 possess magic characteristics, supported by the energetic parameters and AdNDP bonding analyses.

Synergistically enhanced discharged energy density and efficiency achieved in designed polyetherimide-based composites via asymmetrical interlayer structure induced optimized interface effectiveness.

The continuous advancement in energy storage technologies necessitates the iteration of energy storage dielectrics urgently. However, the current state-of-the-art composite films fail to meet the application requirements of energy storage devices, which demand a combination of high discharged energy density (Ue), high energy storage efficiency (η), and excellent high-temperature performance. To address this challenge, we present an innovative interlayer composed of pure BN nanosheets in polyetherimide (PEI)-based asymmetrical multilayered composites doped with Na0.5Bi0.5TiO3 ceramic fibers. This innovative structure confers the PEI-based composites upon synergistic optimization of polarization intensity, breakdown strength and energy loss by designed interface effectiveness adopting tailored filler and interface configuration as modulation means, which can be further confirmed by finite element simulations and comparative experiments. The resultant composite film achieves an excellent Ue of 22.95 J cm-3 and an ultra-high η of 96.81% at ambient temperature, along with high-temperature performances of 12.88 J cm-3 and 79.26% at 150 °C, surpassing all previously reported polymer films in terms of both metrics. This study provides new insights for developing high-performance energy storage dielectrics suitable for practical applications.

Synthesis of ultra-high-temperature nitride amorphous bulk by reaction of halide precursors with sodium in liquid ammonia

Amorphous Si-B-N nanoparticles of uniform composition tunable over the entire range spanning pure Si3N4 to pure BN was synthesized through a simple homogeneous chemical reaction of the mixture of SiCl4 and BBr3 with Na in liquid ammonia. With these amorphous nanopowders, dense amorphous bulk material was obtained with SPS sintering at the temperature before the crystallization. The dense amorphous bulk of Si3B3N7 exhibited the highest value of hardness (8.8 GPa), flexural strength s (545 MPa), and fracture toughness KIC (10.6 MPa m1/2). These are significantly higher than those reported for other crystalline ceramics of the same composition and surpass those of the completely dense crystalline ceramics. The fully-dense amorphous bulk material exhibited excellent resistance to oxidation up to 1550 °C.

Probing the effect of magnesium doping on the structural and electronic properties of boron clusters

In this paper, a global search for the lowest energy structure of Mg2Bn0/- (n = 1–12) clusters is performed based on Density functional theory combined with the particle swarm optimization algorithm program CALYPSO. The geometry, stability, charge transfer, and bonding properties of the clusters were analyzed at the B3LYP/def2-tzvp level. Then Mg2B8 with high symmetry D4h was found to be the magic numbers cluster among them. The doped clusters Mg2Bn0/− were compared with the pure boron clusters Bn+20/− (n = 1–12) at the same level. The following results are obtained: as the number of boron atoms increases, the boron clusters doped with Mg atoms change from a two-dimensional planar or quasi-plane structure to a three-dimensional structure. The doped magnesium atoms are always positively charged in the convex capped position. And the doping of Mg atoms drives the overall stabilization of the boron clusters and makes the clusters more compact. There is a large amount of charge transfer between the Mg atom and the B atom, and the main orbitals involved are the S and p orbitals. There are strong interactions between the two atoms of boron and magnesium. Through the analysis of the bonding properties, it was found that the s-p hybridization mode between MgB is the main reason for the enhanced cluster stability.

Triethylamine borane thermal decomposition for BN low pressure chemical vapour deposition

Triethylamine borane (TEAB) complex was studied as a potential precursor for the thermal low pressure chemical vapour deposition (LPCVD) of pure crystalline sp2-hybridised BN. In particular, its thermal decomposition with or without ammonia was characterised from thermodynamic and experimental points of view in the temperature ranges 400–2000 °C and 300–1300 °C, respectively. NH3 plays a role in the gas phase equilibrium by providing a nitriding source that promotes HCN formation at high temperatures. NH3 is also a source of hydrogen for light hydrocarbons formation as it decomposes. It is thus possible to promote gaseous carbon species formation at high temperatures and limit carbon introduction into coatings by adding ammonia. A turbostratic BN coating could be obtained by CVD from a TEAB/NH3/N2 mixture and conditions chosen thanks to the gas phase decomposition study.

Thermal transfer improvement in polyvinyl alcohol films by mixing with boron nitride nanotubes synthesized using a radio-frequency inductively coupled thermal plasma

Boron nitride nanotubes (BNNTs)/polyvinyl alcohol (PVA) composite films were fabricated to enhance heat transfer capabilities. The incorporation of just 1 wt% of BNNTs into PVA resulted in a remarkable six-fold improvement in heat transfer properties. The BNNTs used in the composite films were synthesized using a thermal plasma method, exhibiting high aspect ratio with diameters ranging from 3 nm to 6 nm. The BNNTs improved the formation of heat transfer networks throughout the PVA films, resulting in enhanced heat transfer properties as compared to both pure PVA and BN nano-powder/PVA composite films. In addition, the addition of BNNTs did not adversely affect the mechanical properties of the BNNTs/PVA composite film such as durability and mechanical strength.

Structure and stability of Cu-doped Bn (n = 1–12) clusters: DFT calculations

The structural and stability properties of Cu-doped boron clusters (BnCu with n = 1–12) are investigated by the SCG (systematic growth algorithm) method in combination with density functional theory (DFT) calculations. The lowest-energy structures of BnCu clusters show similar arrangements with peripheral Cu-doping on preceding pure Bn clusters. Planar and quasi-planar structures are found for n = 3–6 and n = 10–12 while three-dimensional for n = 7–9. The relative stability of the clusters is further analyzed through the average binding energy, the first and second-order energy differences. The results show that B3Cu, B5Cu, B8Cu and B11Cu, are the most stable clusters. The electronic properties such as the ionization potential and electron affinity are calculated and compared with available experimental data. BnCu clusters with even number of boron atoms show higher electron affinities. The bonding character of the clusters is discussed.

A computational investigation on the cyclohexylamine recognition using the pure and Cu-doped BN nanotube

ABSTRACT We scrutinise the adsorption of cyclohexylamine (CHA) on pure and Cu-doped BN-nanotube (Cu@BN-NT) through density functional theory calculations. CHA had a weak interaction with the pristine BN-NT, making BN-NT not suitable to be used as a sensor. However, there was a substantial rise in the reactivity and sensitivity of the BN-NT after replacing the B with metal Cu, based on the standard Gibbs free energy of formation. There is a reduction in the energy gap of the HOMO–LUMO of Cu@BN-NT from 2.28 to 1.42 eV (∼ −37.7%) when CHA was adsorbed, which substantially increased the electrical conductivity. Hence, converting the substantial change in the electrical conductivity into an electronic signal was possible, which demonstrated that the Cu@BN-NT was an encouraging sensor to detect CHA. The computed recovery time for the Cu@BN-NT was 26.8 s, which is short.

Detection of nitrotyrosine (Alzheimer's agent) by B24N24 nano cluster: A comparative DFT and QTAIM insight

A nano-sensor for nitrotyrosine (NT) molecule was found by studying the interactions of NT molecule with new B24N24 nanocages. It was calculated using density functionals in this case. The predicted adsorption mechanisms included physical and chemical adsorption with the adsorption energy of −2.76 to −4.60 and −11.28 to −15.65 kcal mol−1, respectively. The findings show that an NT molecule greatly increases the electrical conductivity of a nanocage by creating electronic noise. Moreover, NT adsorption in the most stable complexes significantly affects the Fermi level and the work function. This means the B24N24 nanocage can detect NT as a Φ–type sensor. The recovery time was determined to be 0.3 s. The sensitivity of pure BN nanocages could be improved without additional expensive structural manipulations. After the NT had been absorbed into the nanocage, UV–Vis spectrum analysis revealed that the transmission wavelength shifted significantly toward 390.07 nm. Hence, a redshift occurs when the NT molecule gets near the B24N24 nanocage. According to the present study model, B24N24 nanocages are possibly promising devices for NT sensors based on their electronic and structural properties.

A DFT study of H2 adsorption on Li-decorated C-doped BN nanochains

By density functional theory (DFT), a new C-doped boron nitrogen nanochain with lithium decoration was designed for hydrogen storage. The lithium adsorption behavior of BN chains with different doping ratio and methods of carbon atoms was systematically studied. The results proved that the metal binding energy could be effectively improved after replacing the N atom in the pure BN chain with C. When a lithium atom was adsorbed, the metal binding energy of the B8N7C nanochain was the highest, reaching 3.79 eV, much higher than the cohesive energy of Li, which avoided lithium cohesion. When two lithium atoms were adsorbed, the metal binding energy of the B6N5C nanochain was the highest, reaching 2.67 eV. For carbon doping ratios of 6.11 %, 6.99 %, 8.18 %, 9.84 %, 12.35 % and 16.58 %, each lithium atom could adsorb almost four H2 molecules, and the average binding energy was about 0.14 eV. When the carbon doping ratio was 16.58 %, the maximum H2 mass ratio of 18.68 wt% was reached. These results all indicate that the Li-BCN series nanochains are a very promising hydrogen storage material.

Stable Ti3+ in B-TiO2/BN based hybrids for efficient photocatalytic reduction

Herein, we explored a new 2D heterostructure by hybridizing BN and TiB2, especially the photocatalytic activity of composite materials. Based on the key strategy of developing BN hybrid photocatalysts to change the band structure, we studied the influences of TiB2 addition on the structures and photocatalytic performances of Ti3+-B codoped TiO2/BN. The Ti3+ existed in TiBO3 enables excellent photocatalytic performances in hydrogen production and nitrogen fixation compared with pure BN. We also carried out first-principle calculations using the VASP program to explain the excellent photocatalytic hydrogen production performances. Finally, the photocatalytic mechanism of such TiO2/BN hybrid photocatalysts was proposed.

Electronic, optical and thermoelectric properties of BN-Be(8,0) nanotube: DFT study

Based on density functional theory calculations, the electronic, optical and thermoelectric properties of pure BN(8,0) nanotube and under Be impurity are discussed. The BN(8,0) nanotube is a pure non-magnetic semiconductor with an energy gap of 3.66 eV along the Γ direction. Still, in the presence of the Be impurity, in BN(8,0) nanotube, we see magnetic asymmetry at its Fermi level, resulting in the BN-Be(8,0) nanotube compound having a half-metallic behavior. The real and imaginary parts of dielectric functions confirm the electronic properties so that in the imaginary part of the dielectric function in both optical directions x, z, in the pure phase, we see a gap of 4 eV, and in the impure form, the gap is about is zero. At energies above 5eV, the real part of the dielectric function is less than one, which represents the super luminescence behavior. Thermoelectric properties show that the effect of Seebeck at room temperature is significant in spin-up and increases with increasing temperature with a positive slope. Also, the merit and power factor coefficients increase at higher temperatures, which indicates the behavior of the power generator.

Enhancing the performance of BN nanosheets as promising anode material for Li-ion batteries with carbon-doping

Li-ion batteries (LIB) are an integral part of portable electronic gadgets. Enhancing the performance of LIB is an active area of research. Here, we investigated the lithiation properties of pure and C-doped BN (BCN) nanosheets using density functional theory. Our calculations show that adsorption energy (Ead) significantly improves via C-doping and it is reciprocal to Li concentration. Depending on Ead, BCN exhibits a wider range of theoretical specific capacity and open circuit voltage (OCV). We obtained a remarkable specific capacity of 778.50 mAhg−1 with an OCV of 0.72 V. A significant charge transfer (0.3e) is also witnessed from Li to nanosheet at local level. A semiconductor to metallic transition is also predicted for higher Li coverage, which pledges for enhanced rate capability. Molecular dynamic analysis indicates that BCN recovers the structural deformations during charging and discharging process. Present calculations show that BCN could be a promising anode material in LIB.

The Synthesis of h-BN-Modified Z-Scheme WO3/g-C3N4 Heterojunctions for Enhancing Visible Light Photocatalytic Degradation of Tetracycline Pollutants.

The photocatalytic performance of common photocatalysts is limited by their low surface area, insufficient absorption of light energy, and fast photogenerated electron–hole recombination rate. The introduction of Z-scheme photocatalysts decorated with hexagonal boron nitride (h-BN) has already been confirmed to be an effective way to extend the surface area and increase the charge separation, thereby enhancing the photocatalytic performance. In this study, a hexagonal boron nitride (h-BN)-decorated WO3/g-C3N4 heterojunction photocatalyst was successfully synthesized via an in situ method using tungstic acid, melamine, and hexagonal boron nitride as the precursors. The physical and chemical properties of the resulting samples were thoroughly characterized. The surface, morphological, and optical properties of the resulting materials were thoroughly characterized by XRD, XPS, SEM, TEM, UV–vis DRS, BET surface areas, PL, and ESR analysis. The WO3/g-C3N4/BN composite exhibited a much higher photocatalytic activity for tetracycline degradation under visible light irradiation than pure g-C3N4, WO3, and BN. The favorable photocatalytic activity of WO3/g-C3N4/BN composites can be ascribed to the increased surface area and enhanced separation efficiency of photogenerated electron–hole pairs by adding h-BN nanosheets and forming the WO3/g-C3N4 heterojunction. This work indicates that the WO3/g-C3N4/BN photocatalyst is a promising material in wastewater treatment.

A situational awareness Bayesian network approach for accurate and credible personalized adaptive radiotherapy outcomes prediction in lung cancer patients.

A situational awareness Bayesian network (SA-BN) approach is developed to improve physicians' trust in the prediction of radiation outcomes and evaluate its performance for personalized adaptive radiotherapy (pART). 118 non-small-cell lung cancer patients with their biophysical features were employed for discovery (n=68) and validation (n=50) of radiation outcomes prediction modeling. Patients' important characteristics identified by radiation experts to predict individual's tumor local control (LC) or radiation pneumonitis with grade≥2 (RP2) were incorporated as expert knowledge (EK). Besides generating an EK-based naïve BN (EK-NBN), an SA-BN was developed by incorporating the EK features into pure data-driven BN (PD-BN) methods to improve the credibility of LC or / and RP2 prediction. After using area under the free-response receiver operating characteristics curve (AU-FROC) to assess the joint prediction of these outcomes, their prediction performances were compared with a regression approach based on the expert yielded estimates (EYE) penalty and its variants. In addition to improving the credibility of radiation outcomes prediction, the SA-BN approach outperformed the EYE penalty and its variants in terms of the joint prediction of LC and RP2. The value of AU-FROC improves from 0.70 (95% CI: 0.54-0.76) using EK-NBN, to 0.75 (0.65-0.82) using a variant of EYE penalty, to 0.83 (0.75-0.93) using PD-BN and 0.83 (0.77-0.90) using SA-BN; with similar trends in the validation cohort. The SA-BN approach can provide an accurate and credible human-machine interface to gain physicians' trust in clinical decision-making, which has the potential to be an important component of pART.

Dielectric Properties of BN-ZnO-GNP Doped PU-EG Composites

In this study, ZnO and GNP were added separately and together to improve the dielectric constant values of hexagonal boron nitride. Polyurethane and glycerol were used as binders. The productions were carried out by dispersing each additive separately in acetone and then coating it with the doctor blade method on aluminium foil. The characterizations were carried out with FTIR and SEM. Then, the capacitance values of each composite were first measured with the LCR meter and then the dielectric constant were calculated. According to the results, the highest dielectric constant values were obtained at the 100 and 120 Hz frequencies. At the frequency value of 100 kHz, the lowest dielectric constant was obtained in all composites. Compared to pure BN, an increase of 115% was achieved with ZnO contribution, while an increase of up to 145% was achieved with GNP contribution. The highest increase was achieved up to 160% with ZnO + GNP contribution. In addition, with the contribution of ZnO + GNP, the amount of decrease at high frequencies was less than the others. This is thought to be due to the combined effect of both ZnO and GNP, which has a large surface area.

Effect of ammonia gas on electrical properties of boron nitride/nickel oxide (BN80/NiO20) nanocomposite

Hybrid materials exhibit excellent properties than their components. Herein, boron nitride and boron nitride/nickel oxide (BN80/NiO20) nanocomposite films were deposited by the drop-casting method. X-ray diffraction, Raman spectroscopy and field emission scanning electron microscopy techniques have been utilized for determining structural, defect chemistry and morphological properties of deposited films. The structural analysis confirmed the formation of BN and NiO phases. Nelson–Riley Factor analysis and Raman analysis revealed the presence of defect states in BN80/NiO20 film. Electrical properties of films were studied in the presence of various concentrations of ammonia gas molecules at different temperatures. BN80/NiO20 composite film showed higher resistivity in the presence of ammonia gas than pure BN film. Variation of electrical resistivity with ammonia gas concentration has been explained through a proposed model. Also, to obtain the resistivity variation concerning ammonia gas concentrations at different temperatures, the linear regression method was used. This work insight the electrical behavior of composite material at different gas concentrations which opens these materials for exploration towards gas sensing and different functional applications.