Boron Nitride Nanosheets for Metal Protection

Although the high impermeability of graphene makes it an excellent barrier to inhibit metal oxidation and corrosion, graphene can form a galvanic cell with the underlying metal that promotes corrosion of the metal in the long term. Boron nitride (BN) nanosheets which have a similar impermeability could be a better choice as protective barrier, because they are more thermally and chemically stable than graphene and, more importantly, do not cause galvanic corrosion due to their electrical insulation. In this study, the performance of commercially available BN nanosheets grown by chemical vapor deposition as a protective coating on metal has been investigated. The heating of the copper foil covered with the BN nanosheet at 250 {\deg}C in air over 100 h results in dramatically less oxidation than the bare copper foil heated for 2 h under the same conditions. The electrochemical analyses reveal that the BN nanosheet coating can increase open circuit potential and possibly reduce oxidation of the underlying copper foil in sodium chloride solution. These results indicate that BN nanosheets are a good candidate for oxidation and corrosion protection, although conductive atomic force microscopy analyses show that the effectiveness of the protection relies on the quality of BN nanosheets.Comment: With Supporting Informatio

Atomically Thin Boron Nitride: Unique Properties and Applications

Atomically thin boron nitride (BN) is an important two-dimensional (2D) nanomaterial, with many properties distinct from graphene. In this feature article, these unique properties and associated applications often not possible from graphene are outlined. The article starts with characterization and identification of atomically thin BN. It is followed by demonstrating their strong oxidation resistance at high temperatures and applications in protecting metals from oxidation and corrosion. As flat insulators, BN nanosheets are ideal dielectric substrates for surface enhanced Raman spectroscopy (SERS) and electronic devices based on 2D heterostructures. The light emission of BN nanosheets in the deep ultraviolet (DUV) and ultraviolet (UV) regions are also included for its scientific and technological importance. The last part is dedicated to synthesis, characterization, and optical properties of BN nanoribbons, a special form of nanosheets

Exploring How Blockchain Impacts Loyalty Program Participation Behaviors: An Exploratory Case Study

How to keep customers motivated in participative behaviors remains one major challenge in extant loyalty program (LP) studies. While some companies have initiated efforts to utilize blockchain-based distributed ledgers and smart contract capabilities to enhance customer experience and improve LP efficiencies, academic assessment of blockchain application in the LP context remains scarce. This research attempts to establish a theoretical overview of how the key natures of blockchain influence customers’ varying motivations (economy, autonomy, competence and relatedness) and perceived value, which consequently induce participative behaviors in a loyalty points context. Then, using an exploratory case study of Bubichain in China, we verify that the blockchain-enabled loyalty points scheme not only improves customers’ economic perceived value by meeting their economic motives, as the traditional one does, but also enhances their social interaction and psychological self-fulfillment value perception by meeting their intrinsic motivations, thus increasing customers’ experience and participation behaviors

In vitro micro-propagation of Longiflorum-Asiatic (LA) hybrids lily (Lilium) cultivar ‘eyeliner’

Bulblets propagation by tissue culture was one of the key techniques in the production of lily (Lilium) bulbs. Therefore, in vitro micro propagation of lily bulblets was studied in detail in this paper. L A hybrids lily cultivar ‘eyeliner’ was selected as the materials. By using the method of orthogonal design, the following were concluded from the research: the optimum treatment and disinfection methods of ‘eyeliner’ bulb scales was soaking in 1:500 carbendazim solution for 30 min, disinfection in 75% alcohol for 10 to 60 s, disinfection in 2% NaClO solution for 15 min; the optimum medium for bud induction of ‘eyeliner’ was MS + 0.5 mg·L-1 6-benzyl aminopurine (6-BA) + 0.1 mg·L-1 naphlene acetic acid (NAA) + 90 g·L-1 sucrose, and 25°C and in darkness; the optimum medium for bulblets induction of ‘eyeliner’ was 2MS + 1.0 mg·L-1 6-BA + 0.5 mg·L-1 NAA + sucrose 90 g·L-1 + Paclobutrazol (PP333) 2 mg·L-1; the optimum culture condition for bulblets induction of ‘eyeliner’ was 20°C, 14 h·day-1 lightness + 10 h·day-1 darkness. The optimum medium for rooting culture of ‘eyeliner’ was ½ MS + 0.8 mg·L-1 NAA + 3 g·L-1 activated charcoal, 20°C, 14 h·day-1 lightness + 10 h·day-1 darkness.Keywords: Lily bulb, orthogonal experiment, in vitro micro propagatio

Single deep ultraviolet light emission from boron nitride nanotube film

Light in deep ultraviolet DUV region has a wide range of applications and the demand for finding DUV light emitting materials at nanoscale is increasingly urgent as they are vital for building miniaturized optic and optoelectronic devices. We discover that boron nitride nanotubes BNNTs with a well-crystallized cylindrical multiwall structure and diameters smaller than 10 nm can have single DUV emission at 225 nm 5.51 eV. The measured BNNTs are grown on substrate in the form of a thin film. This study suggests that BNNTs may work as nanosized DUV light sources for various applications. © 20

Boron Nitride Nanosheets Improve Sensitivity and Reusability of Surface Enhanced Raman Spectroscopy

Surface enhanced Raman spectroscopy (SERS) is a useful multidisciplinary analytic technique. However, it is still a challenge to produce SERS substrates that are highly sensitive, reproducible, stable, reusable, and scalable. Here, we demonstrate that atomically thin boron nitride (BN) nanosheets have many unique and desirable properties to help solve this challenge. The synergic effect of the atomic thickness, high flexibility, stronger surface adsorption capability, electrical insulation, impermeability, high thermal and chemical stability of BN nanosheets can increase the Raman sensitivity by up to two orders, and in the meantime attain long-term stability and extraordinary reusability not achievable by other materials. These advances will greatly facilitate the wider use of SERS in many fields

Strong Oxidation Resistance of Atomically Thin Boron Nitride Nanosheets

Investigation on oxidation resistance of two-dimensional (2D) materials is critical for many of their applications, because 2D materials could have higher oxidation kinetics than their bulk counterparts due to predominant surface atoms and structural distortions. In this study, the oxidation behavior of high-quality boron nitride (BN) nanosheets of 1-4 layer thick has been examined by heating in air. Atomic force microscopy and Raman spectroscopy analyses reveal that monolayer BN nanosheets can sustain up to 850 {\deg}C and the starting temperature of oxygen doping/oxidation of BN nanosheets only slightly increases with the increase of nanosheet layer and depends on heating conditions. Elongated etch lines are found on the oxidized monolayer BN nanosheets, suggesting that the BN nanosheets are first cut along the chemisorbed oxygen chains and then the oxidative etching grows perpendicularly to these cut lines. The stronger oxidation resistance of BN nanosheets suggests that they are more preferable for high-temperature applications than graphene

HIV-1 variants with a single-point mutation in the gp41 pocket region exhibiting different susceptibility to HIV fusion inhibitors with pocket- or membrane-binding domain

AbstractEnfuvirtide (T20), the first FDA-approved peptide HIV fusion/entry inhibitor derived from the HIV-1 gp41 C-terminal heptad-repeat (CHR) domain, is believed to share a target with C34, another well-characterized CHR-peptide, by interacting with the gp41 N-terminal heptad-repeat (NHR) to form six-helix bundle core. However, our previous studies showed that T20 mainly interacts with the N-terminal region of the NHR (N-NHR) and lipid membranes, while C34 mainly binds to the NHR C-terminal pocket region. But so far, no one has shown that C34 can induce drug-resistance mutation in the gp41 pocket region. In this study, we constructed pseudoviruses in which the Ala at the position of 67 in the gp41 pocket region was substituted with Asp, Gly or Ser, respectively, and found that these mutations rendered the viruses highly resistant to C34, but sensitive to T20. The NHR-peptide N36 with mutations of A67 exhibited reduced anti-HIV-1 activity and decreased α-helicity. The stability of six-helix bundle formed by C34 and N36 with A67 mutations was significantly lower than that formed by C34 and N36 with wild-type sequence. The combination of C34 and T20 resulted in potent synergistic anti-HIV-1 effect against the viruses with mutations in either N- or C-terminal region in NHR. These results suggest that C34 with a pocket-binding domain and T20 containing the N-NHR- and membrane-binding domains inhibit HIV-1 fusion by interacting with different target sites and the combinatorial use of C34 and T20 is expected to be effective against HIV-1 variants resistant to HIV fusion inhibitors