Polymerizable C70 derivatives with acrylate functionality for efficient and stable solar cells

Fullerene-based organic solar cells are generally suffering from severe microstructure evolution occurring in their bulk heterojunction active layers and thus are extremely stable. To address it, four polymerizable C₇₀ fullerene derivatives, [6,6]-phenyl-C₇₁-ethyl acrylate (PC₇₁EA), [6,6]-phenyl-C₇₁-propyl acrylate (PC₇₁PrA), [6,6]-phenyl-C₇₁-butyl acrylate (PC₇₁BA), and [6,6]-phenyl-C₇₁-pentyl acrylate (PC₇₁PeA), have been designed, synthesized, and investigated. These fullerene compounds have a molecular structure, shape and size very like the conventional C₇₀ fullerene acceptor, [6,6]-phenyl-C₇₁-butyric acid methyl ester (PC₇₁BM), and have been found no different in their light absorption, redox potentials, and frontier orbital energy levels. Using these fullerene acrylates individually as acceptor and poly(3-hexylthiophene) as donor, organic solar cells have been fabricated and gave optimal efficiencies ranging from 3.32% to 4.16%, comparable to PC₇₁BM-based reference cells (4.06%). Owing to their acrylate functionality, these fullerene derivatives can turn into insoluble upon heating, and thus endow their solar cell devices much better thermostability than PC₇₁BM-based reference cells. The best one, coming from PC₇₁PeA devices, reported an optimal efficiency of 4.16%, and maintained 91.7% efficiency after heat treatment at 150 °C for 35 h. As a sharp contrast, the PC₇₁BM reference cell dropped its optimal efficiency from 4.06% to 0.48% only after 5 h heat treatment. X-ray diffraction, optical and atomic force microscopy, and space-charge-limited current method have been carried out to understand active layer structure, morphology, and charge mobility change during heat treatment.     

Bulk metallic glasses based on ytterbium and calcium

We report the formation of a family of bulk metallic glasses (BMGs) based on rare earth element of ytterbium and alkaline earth element of calcium. The glass-forming ability, atomic packing density and corrosion behaviors of the BMGs show an extremum around the eutectic point with the change of the concentration of Yb and Ca.     

An Optical Sensing Platform for Beta-Glucosidase Activity Using Protein-Inorganic Hybrid Nanoflowers

In this work, a convenient and dual-signal readout optical sensing platform for the sensitively and selectively determination of beta-glucosidase (β-Glu) activity was reported using protein-inorganic hybrid nanoflowers [BSA-Cu₃(PO₄)₂·3H₂O] possessing peroxidase-mimicking activity. The nanoflowers (NFs) were facilely synthesized through a self-assembled synthesis strategy at room temperature. The as-prepared NFs could catalytically convert the colorless and non-fluorescent Amplex Red into colored and highly fluorescent resorufin in the presence of hydrogen peroxide via electron transfer process. β-Glu could hydrolyze cyanogenic glycoside, using amygdalin (Amy) as a model, into cyanide ions (CN^?), which can subsequently efficiently suppress the catalytic activity of NFs, accompanied with the fluorescence decrease and the color fading. The concentration of CN^? was controlled by β-Glu-triggered enzymatic reaction of Amy. Thus, a sensing system was established for fluorescent and visual determination of β-Glu activity. Under the optimum conditions, the present fluorescent and visual bimodal sensing platform exhibited good sensitivity for β-Glu activity assay with a detection limit of 0.33 U·L^?1. The sensing platform was further applied to determinate β-Glu in real samples and satisfactory results were attained. Additionally, the optical sensing system can potentially be a promising candidate for β-Glu inhibitors screening.

     

Lithium metal batteries for high energy density: Fundamental electrochemistry and challenges

The dependence on portable devices and electrical vehicles has triggered the awareness on the energy storage systems with ever-growing energy density.Lithium me...     

Sustainable recycling of titanium from TiO2 in spent SCR denitration catalyst via molten salt electrolysis

Spent catalyst used for denitration by selective catalytic reduction (spent SCR denitration catalysts) is one of the important urban mines due to the high conte...     

制备工艺条件对SiO2薄膜非均质特性的影响

薄膜材料的生长过程随镀膜机尺寸的增大而呈现新的规律,为制备膜层均匀性好、材料均质的大尺寸光学元件,分别在不同离子源能量、沉积压强、基板加热温度及基板转速条件下,采用离子辅助电子束蒸发方法制备了不同单层SiO2薄膜样品;利用分光光度计及椭偏仪分别对样品的透过率及椭偏参数进行测量,并对测量结果进行拟合得到不同样品的折射率及非均质特性。实验结果表明,工件架转速是使大尺寸SiO2薄膜材料产生非均质特性的主要影响因素,离子源能量、基板温度、沉积压强通过影响材料生长过程对材料的非均质特性产生调控;对于大尺寸薄膜光学元件,工件架转速存在限制的条件下,优化其他工艺参数可以获得均质SiO2薄膜材料,该结果对于制备具有优良性能的大尺寸薄膜光学元件具有借鉴意义。     

Existence of two periodic solutions for a non-autonomous SIR epidemic model

A non-autonomous SIR model with periodic transmission rate and a constant removal rate is formulated. By using the continuation theorem of coincidence degree theory, sufficient conditions for the existence of at least two positive periodic solutions are obtained. The stability of the periodic solution for small seasonality is investigated. Numerical simulations are done to show our theoretical results.     

Solvothermal syntheses,crystal structure,and photoluminescent properties of two Cu(I) coordination polymers constructed by bisimidazole ligands

Journal of Structural Chemistry - Two Cu(I) coordination polymers {[Cu2(bibp)2]·bdc·3H2O} n (1) and {[Cu3(bib)3]·btc·5H2O} n (2), where bibp =...     

In Vitro Anticancer Activity of Nanoformulated Mono- and Di-nuclear Pt Compounds

Nanoformulations of mononuclear Pt complexes cis-PtCl₂(PPh₃)₂ ( 1 ), [Pt(PPh₃)₂(L−Cys)] ⋅ H₂O ( 3 , L−Cys=L-cysteinate), trans-PtCl₂(PPh₂PhNMe₂)₂ ( 4 ; PPh₂PhNMe₂=4-(dimethylamine)triphenylphosphine), trans-PtI₂(PPh₂PhNMe₂)₂ ( 5 ) and dinuclear Pt cluster Pt₂(μ-S)₂(PPh₃)₄ ( 2 ) have comparable cytotoxicity to cisplatin against murine melanoma cell line B16F10. Masking of these discrete molecular entities within the hydrophobic core of Pluronic® F-127 significantly boosted their solubility and stability, ensuring efficient cellular uptake, giving in vitro IC₅₀ values in the range of 0.87–11.23 μM. These results highlight the potential therapeutic value of Pt complexes featuring stable Pt−P bonds in nanocomposite formulations with biocompatible amphiphilic polymers.     

Synthesis and Crystal Structure of [1,2,4]-Triazolo-annulated 3-Aza-A-homocholestane Derivative: A Novel Pentaheterocyclic Ring System

Abstract  

A novel pentaheterocyclic ring system derived from (5α)-cholestan-3-one, i.e. [1R-[1α(R*),3aβ,3bα,5aβ,12aα,12bβ,14aα]]-1-(1,5-dimethylhexyl)-1,2,3,3a,3b,4,5,11,12,12a,12b,13,14,14a-tetradecahydro-8,12a,14a-trimethyl-9-(2,4,6-trichlorophenyl)-cyclopenta[5,6]naphtho[2,1-d][1,2,4]triazolo[1,5-a]azepinium hexachloroantimonate (6) has been synthesized via the reverse-electron-demand 1,3-dipolar cycloaddition of the 1-aza-2-azoniaallene cation 4 to the triple bond of acetonitrile followed by ring enlargement. The structure of 6 was determined by NMR, IR and high-resolution mass spectra, and unequivocally confirmed by X-ray crystallographic analysis. The title compound crystallizes in monoclinic class under the space group P2-1 with a = 8.163(3) ?, b = 11.214(4) ?, c = 24.191(9) ?, α = 90°, β = 97.740(5)°, and γ = 90°. The five-membered triazole ring is essentially planar and aromatic, while the seven-membered azepine ring is not planar, but adopts a chair-like conformation.