FeO(OH)@C-Catalyzed Selective Hydrazine Substitution of p-Nitro-Aryl Fluorides and their Application for the Synthesis of Phthalazinones

An efficient hydrazine substitution of p-nitro-aryl fluorides with hydrazine hydrates catalyzed by FeO(OH)@C nanoparticles is described. This hydrazine substitutions of p-nitro-aryl fluorides bearing electron-withdrawing groups proceeded efficiently with high yield and selectivity. Similarly, hydrogenations of p-nitro-aryl fluorides containing electron-donating groups also smoothly proceeded under mild conditions. Furthermore, with these prepared aryl hydrazines, some phthalazinones, interesting as potential structures for pharmaceuticals, have successfully been synthesized in high yields.     

Analysis of the acid and alkali resistance of superhydrophobic paper mulch

Agricultural paper mulch is an indispensable part of modern agriculture. It had the functions of heat preservation, moisture preservation, insect resistance, disease prevention, and weed growth inhibition. In order to extend the service life of the paper mulch, we use the solution immersion method to modify the surface of the paper mulch. A super-hydrophobic paper mulch is mainly prepared by using hydrophobic silica. The static contact angle of the super-hydrophobic paper mulch with water is 160.6°. The super-hydrophobic paper mulch samples were immersed in acid solution (pH?=?4.6 H₂SO₄) and alkaline solution (pH?=?8.5 NaOH). The main instruments are contact angle tester, tensile testing machine and high-speed camera. The hydrophobic properties, mechanical properties and rebound properties of the two kinds of paper mulches were compared. The results showed that the tensile strength and droplet bounce height of the superhydrophobic paper mulch decreased after being soaked in acid or alkaline solution for 48 h. The mass loss rate of paper mulch was more significant in acid solution, but its contact angle was still greater than 145°, and it had good bounce performance. After observing the microscopic morphology of its surface, it was found that silica had a micro-rough structure on the surface of the paper mulch. The method was simple and environmentally friendly, and can alleviate the problem of poor acid and alkali corrosion resistance of the paper mulch, and had extraordinary significance for environmental protection.

     

Dyeing behavior and mechanism of Crocein Orange G on carboxymethyl cotton fabric

Cellulose - Traditional cotton fiber dyeing requires an abundance of salt, which leads to environmental pollution. Consequently, decreasing or eliminating the use of salt has become the primary...     

Cationic and temperature-sensitive liposomes loaded with eugenol for the application to silk

Silk has been widely used in the clothing industry due to their soft and smooth features, good biocompatibility, good heat dissipation, warmth and ultraviolet resistance. The application of fragrance to silk can significantly improve the performance of silk. However, there are two key scientific problems that need to be solved: slowing down the release rate of fragrances and increasing the scent lasting time of silk. In this study, cationic and temperature-sensitive liposomes were designed and prepared to encapsulate eugenol. These fragrance-loaded liposomes significantly slowed down the release rate of the fragrance and controlled the release rate of the fragrance in a thermo-sensitive manner. The liposomes adhered to the silk through electrostatic adsorption interaction. The positive charge on the fragrance-loaded liposomes neutralized much negative charge on silk and thereby increasing the adhesion efficiency.     

Encapsulation of Phosphomolybdate Within Metal–Organic Frameworks with Dual Enzyme-like Activities for Colorimetric Detection of H2O2 and Ascorbic acid

Developing artificial enzyme mimetics for the detection of small biomolecules are a current research interest because natural enzymes bear some serious disadvantages, such as their catalytic activity can be easily inhibited and they can be digested by proteases. Herein, a heteropoly acids (HPA) encapsulating metal–organic framework (MOF) with metal-carbene structure, [Cu₁₀(H₃trz)₄(Htrz)₄][PMo₁₂VO₄₁] (PMA-MOF) as bifunctional enzyme-mimetic catalyst for colorimetric detection of hydrogen peroxide (H₂O₂) and ascorbic acid (AA) was designed and synthesized. Thanks to the good stability and the synergistic effect of PMA and MOF, PMA-MOF exhibits the lower limit of detection (0.222 μM towards H₂O₂ and 0.0046 μM to AA), and the smaller Km value (0.0138 mM for H₂O₂ and 0.136 mM for o-phenylenediamine) compared to most reported MOF- and HPA-based enzyme-mimetic catalyst, to the best our knowledge.

     

Formation and Structures of the μ4-Oxygen-Bridged High-Nuclearity Lead(II) Clusters from a Lead Propane-2-thiolate Complex

Journal of Cluster Science - Interaction of [Pb(SiPr)2]n with 1.5 equiv. of AgNO3 in DMF under aerobic conditions at room temperature gave a cationic lead-centered thiolate cluster...     

Thermal behaviors and kinetic analysis of two natural kaolinite samples selected from Qingshuihe region in Inner Mongolia in China

Journal of Thermal Analysis and Calorimetry - The thermal characteristic behaviors of two kaolinite samples selected from Qingshuihe region in Inner Mongolia in China were studied through...     

Topochemical polymerisation of assembled diacetylene macrocycle bearing dibenzylphosphine oxide in solid state

Novel diacetylene macrocycles 1 and 2 bearing dibenzylphosphine oxide were synthesised via Eglinton acetylenic intramolecular coupling. The X-ray analysis of crystals of macrocycles 1 and 2 demonstrated that the better-aligned tubular supramolecular structure was formed in macrocycle 1 than in macrocycle 2, which provided the possibility of diacetylene topochemical polymerisation in solid state of macrocycle 1. UV–vis, Raman spectroscopy and X-ray analysis indicated that the crystals of macrocycle 1 could undergo topochemical diacetylene polymerisation only on their surface by light irradiation; differential scanning calorimetry, solid-state ¹³C NMR spectroscopy and solubility test demonstrated that the crystals of macrocycle 1 could undergo diacetylene topochemical polymerisation inside solid by heat. As expected, based on the topological analysis of crystal structure, the crystals of macrocycle 2 could not undergo diacetylene topochemical polymerisation either by light irradiation or heat.     

Preconcentration and separation of <Superscript>99</Superscript>Tc in groundwater by using TEVA resin

An effort has been made to optimize the counting time for low-level measurement of naturally occurring radioactive material (NORM) by considering the standard deviation between the activity values of different photopeaks and counting error. It is observed that at lower counting time, relative standard deviation (RSD) varies randomly, but attains a gradual trend with increasing time and also comes closure to the counting error. Therefore minimum counting time for low-level NORM measurement of ²³⁸U and ²³²Th would be the time required to stabilize the RSD values.     

Radiolysis products and degradation mechanism studies on di-1-methyl heptyl methyl phosphonate

Di-1-methyl heptyl methyl phosphonate (DMHMP) is a promising alternative extractant for Th-U fuel reprocessing, in which the irradiation stability of extractant should be systematically studied. In this paper, the radiolysis products of DMHMP were analyzed qualitatively and quantitatively with gas and ion chromatograph, the possible radiolysis mechanism of DMHMP was also concluded. Moreover, the effect of structure on the radiolysis products and irradiation stability of neutral organophosphorus compound extractant was also discussed.