scholarly journals Boron Nitride Nanostructured: Synthesis, Characterization and Potential Use in Cosmetics

2013 ◽  
Vol 04 (01) ◽  
pp. 22-28 ◽  
Author(s):  
Líliam Márcia Silva Ansaloni ◽  
Edésia Martins Barros de Sousa
Keyword(s):  
Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3507
Author(s):  
Zhen Shi ◽  
Sheng-Yuan Xia

The scavenging and detection of sulfur hexafluoride (SF6) decomposition products (SO2, H2S, SO2F2, SOF2) critically matters to the stable and safe operation of gas-insulated switchgear (GIS) equipment. In this paper, the Rh-doped nitrogen vacancy boron nitride monolayer (Rh-VNBN) is proposed as a gas scavenger and sensor for the above products. The computational processes are applied to investigate the configurations, adsorption and sensing processes, and electronic properties in the gas/Rh-VNBN systems based on the first-principle calculations. The binding energy (Eb) of the Rh-VNBN reaches −8.437 eV, while the adsorption energy (Ead) and band gap (BG) indicate that Rh-VNBN exhibits outstanding adsorption and sensing capabilities. The density of state (DOS) analysis further explains the mechanisms of adsorption and sensing, demonstrating the potential use of Rh-VNBN in sensors and scavengers of SF6 decomposition products. This study is meaningful as it explores new gas scavengers and sensors of SF6 decomposition products to allow the operational status assessment of GIS equipment.


2020 ◽  
Vol 6 (10) ◽  
pp. eaay4958 ◽  
Author(s):  
Hyo Ju Park ◽  
Janghwan Cha ◽  
Min Choi ◽  
Jung Hwa Kim ◽  
Roland Yingjie Tay ◽  
...  

Hexagonal boron nitride (hBN) is an insulating two-dimensional (2D) material with a large bandgap. Although known for its interfacing with other 2D materials and structural similarities to graphene, the potential use of hBN in 2D electronics is limited by its insulating nature. Here, we report atomically sharp twin boundaries at AA′/AB stacking boundaries in chemical vapor deposition–synthesized few-layer hBN. We find that the twin boundary is composed of a 6′6′ configuration, showing conducting feature with a zero bandgap. Furthermore, the formation mechanism of the atomically sharp twin boundaries is suggested by an analogy with stacking combinations of AA′/AB based on the observations of extended Klein edges at the layer boundaries of AB-stacked hBN. The atomically sharp AA′/AB stacking boundary is promising as an ultimate 1D electron channel embedded in insulating pristine hBN. This study will provide insights into the fabrication of single-hBN electronic devices.


2021 ◽  
Author(s):  
Sachin Sharma ◽  
Laurent Souqui ◽  
Henrik Pedersen ◽  
Hans Högberg

Thin films of boron nitride in its sp2-hybridized form (sp2-BN) have potential use in UV-devices and dielectrics. Here, we explore chemical vapor deposition (CVD) of sp2-BN on various cuts of sapphire; Al2O3(112̅0), Al2O3(11̅02), Al2O3(11̅00) and Al2O3 (0001) using two CVD processes with different boron precursors; triethylborane (TEB) and trimethylborane (TMB). Fourier transform infrared spectroscopy (FTIR) showed that sp2-BN grows on all the sapphire substrates, using X-ray diffraction (XRD), 2θ/ω diffractograms showed that only Al2O3(112̅0) and Al2O3(0001) renders crystalline films and using phi(ɸ)-scans the growth of rhombohedral polytype (r-BN) films on these substrates is confirmed. These films are found to be epitaxially grown on an AlN interlayer with a higher crystalline quality for the films grown on the Al2O3(112̅0) substrate which is determined using omega(ω)-scans. Our study suggests that Al2O3(112̅0) is the most favorable sapphire substrate to realize the envisioned applications of r-BN films.


Author(s):  
A. Baronnet ◽  
M. Amouric

The origin of mica polytypes has long been a challenging problem for crystal- lographers, mineralogists and petrologists. From the petrological point of view, interest in this field arose from the potential use of layer stacking data to furnish further informations about equilibrium and/or kinetic conditions prevailing during the crystallization of the widespread mica-bearing rocks. From the compilation of previous experimental works dealing with the occurrence domains of the various mica "polymorphs" (1Mr, 1M, 2M1, 2M2 and 3T) within water-pressure vs temperature fields, it became clear that most of these modifications should be considered as metastable for a fixed mica species. Furthermore, the natural occurrence of long-period (or complex) polytypes could not be accounted for by phase considerations. This highlighted the need of a more detailed kinetic approach of the problem and, in particular, of the role growth mechanisms of basal faces could play in this crystallographic phenomenon.


Author(s):  
X. Qiu ◽  
A. K. Datye ◽  
T. T. Borek ◽  
R. T. Paine

Boron nitride derived from polymer precursors is of great interest for applications such as fibers, coatings and novel forms such as aerogels. The BN is prepared by the polymerization of functionalized borazine and thermal treatment in nitrogen at 1200°C. The BN powders obtained by this route are invariably trubostratic wherein the sheets of hexagonal BN are randomly oriented to yield the so-called turbostratic modification. Fib 1a and 1b show images of BN powder with the corresponding diffraction pattern in fig. 1c. The (0002) reflection from BN is seen as a diffuse ring with occational spots that come from crystals of BN such as those shown in fig. 1b. The (0002) lattice fringes of BN seen in these powders are the most characteristic indication of the crystallinity of the BN.


Author(s):  
Z. Liliental-Weber ◽  
C. Nelson ◽  
R. Ludeke ◽  
R. Gronsky ◽  
J. Washburn

The properties of metal/semiconductor interfaces have received considerable attention over the past few years, and the Al/GaAs system is of special interest because of its potential use in high-speed logic integrated optics, and microwave applications. For such materials a detailed knowledge of the geometric and electronic structure of the interface is fundamental to an understanding of the electrical properties of the contact. It is well known that the properties of Schottky contacts are established within a few atomic layers of the deposited metal. Therefore surface contamination can play a significant role. A method for fabricating contamination-free interfaces is absolutely necessary for reproducible properties, and molecularbeam epitaxy (MBE) offers such advantages for in-situ metal deposition under UHV conditions


Author(s):  
D. L. Medlin ◽  
T. A. Friedmann ◽  
P. B. Mirkarimi ◽  
M. J. Mills ◽  
K. F. McCarty

The allotropes of boron nitride include two sp2-bonded phases with hexagonal and rhombohedral structures (hBN and rBN) and two sp3-bonded phases with cubic (zincblende) and hexagonal (wurtzitic) structures (cBN and wBN) (Fig. 1). Although cBN is synthesized in bulk form by conversion of hBN at high temperatures and pressures, low-pressure synthesis of cBN as a thin film is more difficult and succeeds only when the growing film is simultaneously irradiated with a high flux of ions. Only sp2-bonded material, which generally has a disordered, turbostratic microstructure (tBN), will form in the absence of ion-irradiation. The mechanistic role of the irradiation is not well understood, but recent work suggests that ion-induced compressive film stress may induce the transformation to cBN.Typically, BN films are deposited at temperatures less than 1000°C, a regime for which the structure of the sp2-bonded precursor material dictates the phase and microstructure of the material that forms from conventional (bulk) high pressure treatment.


2021 ◽  
Vol 23 (1) ◽  
pp. 219-228
Author(s):  
Nabanita Saikia ◽  
Mohamed Taha ◽  
Ravindra Pandey

The rational design of self-assembled nanobio-molecular hybrids of peptide nucleic acids with single-wall nanotubes rely on understanding how biomolecules recognize and mediate intermolecular interactions with the nanomaterial's surface.


1985 ◽  
Vol 4 ◽  
pp. 116-123 ◽  
Author(s):  
P STEHLE ◽  
S ALBERS ◽  
I AMBERGER ◽  
P PFAENDER ◽  
P FURST

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