Metallization of U3O8via catalytic electrochemical reduction with Li2O in LiCl molten salt

The concept of a novel electrochemical reduction process for the treatment of spent nuclear fuels in Li₂O-LiCl molten salt was proposed and fresh tests using U₃O₈ powder were carried out to elucidate the reaction mechanism and verify the feasibility of the process. Electrolysis of Li₂O and reduction of U₃O₈ powder took place simultaneously at the cathode part of the electrolysis cell via a catalytic EC mechanism and the conversion of U₃O₈ to U metal was more than 99%. This revised version was published online in June 2006 with corrections to the Cover Date.     

Synthesis of mesoporous-silica coated multi-branched gold nanoparticles for surface enhanced Raman scattering evaluation of 4-bromomethcathinone

Mesoporous silica-coated multi-branched gold nanoparticles (bAu@mesoSiO₂) aiming for enhanced Raman sensing for 4-bromomethcathinone (4-BMC) detection is reported. In this work, we present an effective strategy to probe the Raman signal of 4-MBC. Morphologies and optical properties of the synthesized materials with different [Au³⁺]/[Au⁰] ratios are characterized utilizing transmission electron microscopy (TEM), UV–vis and mid-infrared spectroscopy. Both experimental and theoretical (simulation) studies were investigated. Taking advantages of gold core branches that provide highly localized and strongly enhanced electromagnetic fields due to plasmon resonance, surface-enhanced Raman scattering (SERS) is observed. The experimental results show that the SERS intensity exhibits a 100-fold increase with the increased average length and quantity of gold branches (nano tips). The analytical performance yielded a detection limit of 0.1?mg/ml for the 4-MBC target within 5?mins. The sensing method will likely find further improvement and broad use in the forensic science. Besides rapid detection and portability, the combination of the Raman effect and enhanced materials imparts other notable advantages, such as its non-contact and free of reagents.     

Redox-Guest-Induced Multimode Photoluminescence Switch for Sequential Logic Gates in a Photoactive Coordination Cage

Molecular or supramolecular level photoluminescence (PL) modulation combining chemical and photonic input/output signals together in an integrated system can provide potential high-density data memorizing and process functions intended for miniaturized devices and machines. Herein, a PL-responsive supramolecular coordination cage has been demonstrated for complex interactions with redox-active guests. PL signals of the cage can be switched and modulated by adding or retracting Fc derivatives or converting TTF into different oxidation states through chemical or photochemical pathways. As a result, reversible or stepwise PL responses are displayed by these host–guest systems because of the occurrence of photoinduced electron-transfer (PET) or fluorescence resonance energy transfer (FREnT) processes, providing unique nanodevice models bearing off/on logic gates or memristor-like sequential memory and Boolean operation functions.     

Synthesis and properties of mono‐ and di‐fluoro‐substituted 2,3‐didodecylquinoxaline‐based polymers for polymer solar cells

We synthesized two new alternating polymers, namely P(Tt‐FQx) and P(Tt‐DFQx) , incorporating electron rich tri‐thiophene and electron deficient 6‐fluoroquinoxaline or 6,7‐difluoroquinoxaline derivatives. Both polymers P(Tt‐FQx) and P(Tt‐DFQx) exhibited high thermal stabilities and the estimated 5% weight loss temperatures are 425 and 460 °C, respectively. Polymers P(Tt‐FQx) and P(Tt‐DFQx) displayed intense absorption band between 450 and 700 nm with an optical band gap (E_g) of 1.78 and 1.80 eV, respectively. The determined highest occupied/lowest unoccupied molecular orbital's (HOMO/LUMO) of P(Tt‐DFQx) (?5.48 eV/?3.68 eV) are slightly deeper than those of P(Tt‐FQx) ( ?5.32 eV/?3.54 eV). The polymer solar cells fabricated with a device structure of ITO/PEDOT:PSS/ P(Tt‐FQx) or P(Tt‐DFQx) :PC₇₀BM (1:1.5 wt %) + 3 vol % DIO/Al offered a maximum power conversion efficiency (PCE) of 3.65% with an open‐circuit voltage (V_oc) of 0.59 V, a short‐circuit current (J_sc) of 10.65 mA/cm² and fill factor (FF) of 59% for P(Tt‐FQx) ‐based device and a PCE of 4.36% with an V_oc of 0.69 V, a J_sc of 9.92 mA/cm², and FF of 63% for P(Tt‐DFQx) ‐based device. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 545–552     

Liquid crystalline epoxy resin with improved thermal conductivity by intermolecular dipole–dipole interactions

To address tremendous needs for developing efficiently heat dissipating materials with lightweights, a series of liquid crystalline epoxy resins (LCEs) are designed and synthesized as thermally conductive matrix. All prepared LCEs possess epoxies at the molecular side positions and cyanobiphenyl mesogenic end groups. Based on several experimental results such as differential scanning calorimetry, polarized optical microscopy, and X‐ray diffraction, it is found that the LCEs exhibited liquid crystalline mesophases. When LCE is cured with a diamine crosslinker, the cured LCE maintains the oriented LC domain formed in the uncured state, ascribing to a presence of dipole–diploe and π–π interactions between cyanobiphenyl mesogenic end groups. Due to the anisotropic molecular orientation, the cured LCE exhibits a high thermal conductivity of 0.46 W m^?1 K^?1, which is higher than those of commercially available crystalline or amorphous epoxy resins. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 708–715     

Adsorption of thorium(IV) from aqueous solutions by poly(cyclotriphosphazene-co-4,4′-diaminodiphenyl ether) microspheres

Journal of Radioanalytical and Nuclear Chemistry - Poly(cyclotriphosphazene-co-4,4′-diaminodiphenyl ether) microspheres (PZA) was based on hexachlorocyclotriphosphazene (HCCP) and...     

Effect of Two‐Dimensional Crystal Orbitals on Fermi Surfaces and Electron Transport in Three‐Dimensional Perovskite Oxides

Perovskite oxides are candidate materials in catalysis, fuel cells, thermoelectrics, and electronics, where electronic transport is vital to their use. While the fundamental transport properties of these materials have been heavily studied, there are still key features that are not well understood, including the temperature‐squared behavior of their resistivities. Standard transport models fail to account for this atypical property because Fermi surfaces of many perovskite oxides are low‐dimensional and distinct from traditional semiconductors. In this work, the low‐dimensional Fermi surfaces of perovskite oxides are chemically interpreted in terms of two‐dimensional crystal orbitals that form the conduction bands. Using SrTiO₃ as a case study, the d/p‐hybridization that creates these low‐dimensional electronic structures is reviewed and connected to its fundamentally different electronic properties. A low‐dimensional band model explains several experimental transport properties, including the temperature and carrier‐density dependence of the effective mass, the carrier‐density dependence of scattering, and the temperature dependence of resistivity. This work highlights how chemical bonding influences semiconductor transport.     

Metal-free and highly regioselective synthesis of N-heteroaryl substituted pyrazoles from α,β-unsaturated N-tosylhydrazones and heteroaryl chlorides

A cascade cyclization/nucleophilic aromatic substitution (S_NAr) reaction of α,β-unsaturated N-tosylhydrazones with N-heteroaryl chlorides was developed for the synthesis of N-heteroaryl pyrazole derivatives. This one-pot reaction provided bi(heteroaryl) derivatives in good to excellent yields and with excellent regioselectivity. The procedure is operationally simple and applicable to large-scale synthesis.     

Development of a PRiME cartridge purification method for rapid determination of malachite green and leucomalachite green in Chinese softshell turtle

A high‐throughput PRiME (process, robustness, improvements, matrix effects, ease of use) sample purification procedure was developed to simplify the multiple steps of traditional SPE in extracting the malachite green and leucomalachite green in Chinese softshell turtle (Pelodiscus sinensis). The sample loading volume, extracting solvent type, and pH value of the employed PRiME hydrophilic‐lipophilic balance cartridge for sample purification were optimized to be 3 mL, acetonitrile, and pH 5, respectively. In comparison with traditional SPE, the PRiME process is cost‐effective, solvent‐saving, and simple to operate, which only consists of a passing through step without traditional sorbent conditioning and impurity washing. Afterward, eluate was analyzed by ultra‐performance liquid chromatography‐tandem mass spectrometry, and the proposed method was validated for linearity (R² > 0.9992), intraday precision (2.44–3.22%), interday precision (3.28–6.58%), sensitivity (LOD ≤ 0.18 μg/kg and, LOQ ≤ 0.60 μg/kg), and recovery (88.7–94.1%, RSD < 6.79%). The results indicated that the PRiME technique can simplify the sample preparation procedure by avoiding the tedious steps, such as conditioning, washing, etc. It would be of significant interest for environmental and food safety applications in the market of Chinese softshell turtle and related products.