An Electrically and Thermally Erasable Liquid Crystal Film Containing NIR Absorbent Carbon Nanotube

Carbon nanotubes (CNTs) coated by a poly(vinylpyrrolidone) (PVP) layer were doped in bistable cholesteric liquid crystal (ChLC) film to provide electric, thermal, or optical erasability controllable films. The CNT/PVP formed a compatible NIR-absorbing film that can generate heat to switch ChLC film from a planar texture to a focal conic texture. The appropriate content of CNT/PVP is provided to achieve a fast thermal response, satisfactory dispersion, and clear display brightness. The ChLC film containing CNT/PVP @ 0.8 (wt.%) saves 51% time at thermal erasing, compared to the ChLC mixture without NIR absorbent. The hybrid organic–inorganic bistable ChLC material reported here extends and offers new applications of ChLC writing tablets

Atomic-Local Environments of Single-Atom Catalysts: Synthesis, Electronic Structure, and Activity

Single-atom catalysts (SACs) hold great promise for maximizing atomic efficiency of supported metals via the ultimate utilization of every single atom. The foreign isolated substitutions anchored on different supports build varieties of local structural centers, changing the physical and chemical properties. Thus, distinct atomic local environments for single-atom catalysts are essential for determining superior catalytic performance for a wide variety of chemical reactions. The examples of synthesizing single atoms on various supports presented here deepen the understanding of the different structural and electronic properties of SACs, in which the metal single atom does not bind with any other atoms of this metal, but substantially interacts with the support ions. Due to the strong support effects, the ubiquitous aggregation of metal single atoms can be addressed, achieving highly stable SACs. This review discusses recent progress in theoretical electronic effects between atomic dopants and supports, which reveal the electronic structures of various SACs and offers guidance for rational prediction and design of highly stable and reactive SACs. It is argued that tuning this interaction by the selection of the supports toward favorable atomic and electronic structures on the surface should be taken into consideration for the development of more efficient SACs

Unsymmetrical Diboron Reagents: Application in Borylation Reactions of Unsaturated Bonds

In the past decades, borylation reactions have received extensive research interest and have developed into effective tools in the synthesis of versatile organoboron compounds. Boranes and symmetrical diboron compounds are commonly utilized as borylating reagents in these transformations, especially in the borylation reactions of unsaturated bonds. More recently, several types of unsymmetrical diboron reagents have been synthesized and applied in these borylation reactions, allowing for complementary chemo- and regioselectivity. This review aimed to highlight the recent development in this rising research field, focusing on new reactivity and selectivity that originates from the use of these unsymmetrical diboron reagents

Assessment and determination of lyoprotectant for survival of freeze-dried Lactobacillus rhamnosus

Currently research of lactic acid bacteria focus primarily on the functional probiotics, which are major beneficial biota in the gastrointestinal tract, have been industrial manufactured. Probiotics confer health benefits on the host need adequate amounts. However, the absence of data makes it difficult to ensure the maintenance biological activities and population of probiotic. In this research, a fractional factorial design and steepest ascent experiment were used to analyze the influence of lyoprotectant as carbohydrates, prebiotics and amino acids on the survival of the probiotic Lactobacillus rhamnosus. The results indicated a maximum survival rate and population of viable bacteria of L. rhamnosus to be 55.84 % and 1.60 ×1011 CFU/g after freeze-dried by using a combination of 10 g/100mL Sucrose, 2.5 g/100mL Isomaltooligosaccharide, 12 g/100mL Hydroxyproline. To a large extent, the survival and viability were dependent on the cryoprotectant used and make probiotics more attractive from a practical application in industrial viewpoint

THEORETICAL STUDIES ON TRIACETONETRIPEROXIDE (TATP) DERIVATIVES TO IMPROVE THEIR PERFORMANCE

Density functional theory (DFT) methods are used to study on TATP derivatives at DFT-B3LYP/6-311++G (d, p) level to improve TATP’s performance. The derivatives are 3,6,9-trimethyl-3,6,9-tris(trifluoromethyl)-1,2,4,5,7,8-hexaoxonane (TATP3F), 3,6,9-trimethyl-3,6,9-tris(nitromethyl)-1,2,4,5,7,8-hexaoxonane (TATPNO2) and (3,6,9-trimethyl-1,2,4,5,7,8-hexaoxonane-3,6,9-triyl)trimethanamine (TATPNH2). Stability and detonation performance of TATP derivatives were investigated. Detonation performance was estimated using density, heat of formation and EXPLO 5 software. Stability was evaluated by geometrical geometry and electronic structure. The simulation results reveal that TATPNO2 has a best oxygen balance, detonation performance (Q=5424 kJ kg-1, P=23.7 Gpa, D=7699 m s-1) and insensitivity. Since TATPNO2 is more excellent than TATP and traditional explosive TNT in detonation performance, it is a candidate of novel high energy density materials

NNB-Type Tridentate Boryl Ligands Enabling a Highly Active Iridium Catalyst for C–H Borylation

Boryl ligands play a very important role in catalysis because of their very high electron-donating property. In this paper, NNB-type boryl anions were designed as tridentate ligands to promote aryl C–H borylation. In combination with [IrCl(COD)]2, they generate a highly active catalyst for a broad range of (hetero)arene substrates, including highly electron-rich and/or sterically hindered ones. This work provides a new NNB-type tridentate boryl ligand to support homogeneous organometallic catalysis

Structural design of anode materials for sodium-ion batteries

With the high consumption and increasing price of lithium resources, sodium ion batteries (SIBs) have been considered as attractive and promising potential alternatives to lithium ion batteries, owing to the abundance and low cost of sodium resources, and the similar electrochemical properties of sodium to lithium. Nevertheless, the lower energy density and limited cycling life of SIBs are still the main challenges impeding their wide application. Tremendous work has been done on anode materials for SIBs, and rational structural design is considered as an effective way to enhance their electrochemical performance. In this review, different types of anode materials for SIBs are summarized according to their reaction mechanism, and the problems for each type are pointed out. Specific structural design approaches for each type of anode material to improve its sodium storage performance are described in detail, and the benefits of different structural designs are explained as well

Nanocomposite Materials for the Sodium-Ion Battery: A Review

Clean energy has become an important topic in recent decades because of the serious global issues related to the development of energy, such as environmental contamination, and the intermittence of the traditional energy sources. Creating new battery-related energy storage facilities is an urgent subject for human beings to address and for solutions for the future. Compared with lithium-based batteries, sodium-ion batteries have become the new focal point in the competition for clean energy solutions and have more potential for commercialization due to the huge natural abundance of sodium. Nevertheless, sodium-ion batteries still exhibit some challenges, like inferior electrochemical performance caused by the bigger ionic size of Na+ ions, the detrimental volume expansion, and the low conductivity of the active materials. To solve these issues, nanocomposites have recently been applied as a new class of electrodes to enhance the electrochemical performance in sodium batteries based on advantages that include the size effect, high stability, and excellent conductivity. In this Review, the recent development of nanocomposite materials applied in sodium-ion batteries is summarized, and the existing challenges and the potential solutions are presented

Crystal structure of 8a,8a′′-oxybis(8aH-8,9-dioxa-3a1λ4-aza-8aλ4-borabenzo[fg]tetracene), C34H22B2N2O5

C34H22B2N2O5, monoclinic, P21/c (no. 14), a = 9.9886(3) Å, b = 17.8995(6) Å, c = 14.3437(5) Å, β = 98.141(3)°, V = 2538.68(15) Å3, Z = 4, Rgt(F) = 0.0391, wRref(F2) = 0.1022, T = 100 K

Effects of different concentrations of sodium ions on the self-assembly of amphotericin B and DPPC at the air-water interface

Amphotericin B is a widely used polyene antifungal drug for the treatment of deep fungal infections. This drug could cause pores on the cell membrane. In this work, we used the dipalmitoylphosphatidylcholine monolayer as the model of cell membrane in half. The influence of Na⁺ions on the interaction between amphotericin B and biomembrane were studied by analysis of phase transition and thermodynamic properties of monolayers. The Na⁺ions may affect the molecular orientation of amphotericin B, and it depends on the concentration of sodium ions. Low concentration of Na⁺ ions has an opposite effect to high concentration of that. The results are helpful for obtaining some information on the influence mechanism in the level of sodium ions on the interaction between amphotericin B and biomembrane in the angle of physics