Efficient removal of anionic dye by protonated APTES modified hydrochar: The effect of cold-activation

The study focused on determining the effect of acidic and basic cold activation on hydrochar (HC) for the removal of methyl orange (MO). HC was prepared by hawthorn seeds (HS) under hydrothermal carbonization. HC was cold-activated with HCl and NaOH, respectively, and they were grafted with aminopropyltriethoxysilane (APTES) and protonated to obtain AHC-N⁺ (acid-activated and modified HC) and BHC-N⁺ (base-activated and modified HC) to determine the effect of acidic and basic activation. They were characterized by elemental analysis, IR, thermal analysis, zeta potential, N₂ adsorption–desorption measurements, and SEM–EDX analysis. The prepared adsorbents displayed MO adsorption due to abundant protonated amine groups. BHC-N⁺ showed higher MO adsorption than AHC-N⁺. The result showed that more protonated APTES groups grafted on the surface of HC via NaOH activation. The obtained data had a good fitting with the Langmuir isotherm and pseudo-second-order kinetic. The maximum adsorption capacity of BHC-N⁺ was 250.38 mg g⁻¹. The adsorption mechanism could be attributed to the electrostatic interactions between MO and protonated amine groups of APTES and hydrogen bonding.     

Selective adsorption behaviors of guest molecules COR in the hexamer host networks at liquid/solid interface

Here,the selective adsorption behaviors of guest molecule COR in two hexamer host grids were investigated by means of scanning tunnelling microscope(STM).The assembled structures of small functional organic molecules TTBTA and TATBA were thermodynamically stable.Interestingly,the introduction of the guest molecule COR destroyed the original hexamer structure of TTBTA and combined with it to form a new triangular host-guest system.Different from TTBTA,the introduction of the guest molecule COR did not affect the six-membered ring structure of TATBA.Furthermore,the co-assembly structure of TTBTA/TATBA/COR was established and the guest molecule COR showed preferential adsorption to the TATBA host grid.Density functional theory(DFT) calculations had been performed to disclose the mechanism of the involved assemblies.     

CHEMICAL STRUCTURE AND FUNCTIONAL PROPERTIES OF AMORPHOUS BORON CARBONITRIDE FILMS

Journal of Structural Chemistry - We report a comprehensive study of the effect of the chemical structure of boron carbonitride films on the variability of their functional characteristics. The...     

Sensitive,Accurate and Selective Determination of Cd(II) Using Anodic Stripping Voltammetry with in-situ Hg-Bi Film Modified Pencil Graphite Electrode After Magnetic Dispersive Solid Phase Microextraction

This paper describes a novel approach to detect Cd(II) using the combination of the differential pulse anodic stripping voltammetry and magnetic nanoparticle based dispersive solid phase microextraction as an efficient, green and accurate method. Currents of Cd(II) increased linearly in the range from 75 to 2000 ng L⁻¹ Cd(II) with a detection limit of 21.6 ng L⁻¹. The RSD values of 2.6 and 6.0 % for 1.00 and 0.10 μg L⁻¹ respectively showed that proposed method has an acceptable repeatability. Recovery values between 92.3 and 98.6 % showed that this approach can be successfully used for determination of Cd(II) in water samples.     

Study on backward-facing step flow and heat transfer characteristics of hybrid nanofluids

Journal of Thermal Analysis and Calorimetry - As high heat dissipation has increasingly become the primary factor restricting the capability of electronic elements, and the high temperature of the...     

Determination of Acetylcysteine in Pharmaceutical Samples by Silicomolybdenum Blue Spectrophotometry

An accurate and fast spectrophotometric method for the determination of acetylcysteine by silicomolybdenum blue has been established. The various effect factors on the determination of acetylcysteine by silicomolybdenum blue spectrophotometry are investigated in detail. The results show that under the optimum reaction conditions, SiO₃^2‐ reacts with Mo₇O₂₄^6‐ to form silicon molybdenum heteropoly acid (H₄Si(Mo₃O₁₀)₄). Then H₄Si(Mo₃O₁₀)₄ is reduced by hydrosulfuryl (‐SH) in acetylcysteine to form silicomolybdenum blue (H₄Si(Mo₃O₁₀)₂(Mo₃O₉)₂). The absorbance of silicomolybdenum blue is measured at the maximal absorption wavelength of 735 nm, and the content of acetylcysteine can be calculated based on this absorbance. A good linear relationship is obtained between the absorbance of silicomolybdenum blue and the concentration of acetylcysteine in the range of 5.040∼25.20 μg⋅mL^‐1. The linear regression equation is A = 0.0272 + 21.484C (mg⋅mL^‐1), with a linear correlation coefficient of 0.9995. This proposed method has been successfully applied to the determination of acetylcysteine in pharmaceutical samples, and the results agree well with those obtained by pharmacopoeial method.     

Syntheses,Structures, and Magnetic Properties of Two Cobalt(II) Metal‐Organic Frameworks Based on Y‐shaped 3,5,4′‐Azobenzenetricarboxylic Acid and Different N‐donor Ligands

Two metal‐organic frameworks, [Co₂(ABTC)(bimh)(OH)] · 2H₂O ( 1 ) and [Co₃(ABTC)₂(dimb)₄]_n ( 2 ) [H₃ABTC = 3,4′,5‐azobenzenetricarboxylic acid, bimh = 1,1′‐(1,4‐hexanediy)bis(imidazole), dimb = 1,4‐bis(1H‐imidazol‐1‐yl)benzene], were prepared under solvothermal conditions and structurally characterized. Complex 1 demonstrates a complicated 3D (3,8)‐connected tfz‐d net with (4³)₂(4⁶.6¹⁷.8⁵) topology. The framework of 2 can be classified as a rare 3D (3,6,6)‐connected net with the Schäfli symbol of (4.6²)₂(4².6¹⁰.8³)(4⁴.6¹⁰.8), and exhibits an intriguing self‐penetrating motif. Meanwhile, the thermal stabilities and magnetic properties for 1 and 2 were also probed.     

Electrodeposition and characterization of Zn–Sn alloy coatings from a deep eutectic solvent based on choline chloride for corrosion protection

With the aim of obtaining high corrosion resistant Zn–Sn alloy coatings from an ionic liquid, the effects of electrodeposition potential and electrolyte composition on the electrodeposition behavior, film composition, morphology and corrosion performance were investigated. Cyclic voltammograms indicate that Zn and Sn were co‐deposited at distinct reduction potentials as pure Zn and Sn elements. In addition, the phase composition analysis also showed that the obtained Zn–Sn alloy deposits (8 wt.%–45 wt.% Zn) consist of a two‐phase mechanical mixture of small aggregates of Zn and Sn metals. The Zn content of the alloy significantly increases as the electrodeposition potential and electrolyte Zn (II)/Sn (II) ratio increase. The corrosion performance study of the obtained Zn–Sn coatings showed that they have a passivation behavior and their corrosion resistance increases as the alloy‐Sn content increases. To improve their morphological properties, ethylene diamine tetraacetic acid additive was introduced into the electrolyte and greatly improved the morphology and corrosion resistance of the deposits. For the first time, it was shown that high corrosion resistance Zn–Sn coatings can be obtained from ionic liquids. Copyright © 2014 John Wiley & Sons, Ltd.     

TiO2修饰La0.6Sr0.4Co0.2Fe0.8O3-δ用于中温固体氧化物燃料电池的阴极

纳米TiO2修饰的La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF)阴极被直接应用于YSZ电解质电池上. TiO2可阻止LSCF和YSZ间的化学反应,抑制SrZrO3的形成. LSCF-0.25 wt% TiO2阴极电池在0.7 V和600°C下的电流密度是LSCF阴极电池的1.6倍.电化学阻抗谱结果表明, TiO2修饰显著加快了氧离子注入电解质的过程,这可能与TiO2抑制了阴极/电解质界面处高电阻SrZrO3层的形成有关.本文为在ZrO2基电解质上使用高性能的(La,Sr)(Co,Fe)O3阴极材料提供了一种简单有效的方法.     

Catalytic Asymmetric Construction of α‐Quaternary Cyclopentanones and Its Application to the Syntheses of (−)‐1,14‐Herbertenediol and (−)‐Aphanorphine

A novel and efficient strategy to build α‐benzylic quaternary cyclopentanones with excellent enantioselectivities (up to 96 % ee) and high yields (up to 99 % yield) has been developed, and its application demonstrated by the first catalytic asymmetric total synthesis of (?)‐1,14‐herbertenediol and the formal synthesis of (?)‐aphanorphine.