Destruction Kinetics of 2,4 Dichlorophenol Aqueous Solutions in an Atmospheric Pressure Dielectric Barrier Discharge in Oxygen

The processes of degradation of 2,4-dichlorophenol (2,4-DCP) aqueous solutions under the action of atmospheric pressure of DBD in oxygen were studied. The degradation of 2,4-DCP proceeds efficiently, the degree of decomposition reaching 100%. The degradation kinetics of 2,4-DCP obeys a formal first-order kinetic law on concentration of 2,4-DCP. The effective rate constants depend weakly on the experimental conditions and are equal to ~ 2 s^?1. Based on experimental data, the energy efficiency of 2,4-DCP decomposition was determined to be in the range of 0.039–0.173 molecules per 100 eV depending on the experimental conditions. The composition of the products was studied by gas chromatography, chromatography-mass spectrometry, UV/visible spectroscopy, fluorescent methods and some chemical methods. The main decomposition products present in the solution were found to be carboxylic acids, aldehydes and chloride ions, whereas carbon dioxide and molecular chlorine appear in the gas. The results obtained are compared with similar data from other advanced oxidation processes (AOP’s) methods.     

Perylene Bisimide In-chain Polyethylene with Unique Self-assembly Nanostructure through Acyclic Diene Metathesis (ADMET) Polymerization

A novel perylene tetracarboxylic acid bisimide(PTCBI) in-chain polyethylene(PE) was first prepared via acyclic diene metathesis(ADMET) polymerization of PTCBI-functionalized α,ω-diene monomer. The polymers could spontaneously self-assemble into hollow cylindrical structures in which the π-π interaction between adjacent PTCBI moieties was enhanced and the electron mobility was possibly promoted. The hydrogenation of as-obtained polymer was readily accomplished, affording the desired precision PTCBI in-chain PE with a saturated backbone, which showed high glass transition temperature(Tg = 63 °C), relatively wide range of light absorption(λ = 200-575 nm), and higher LUMO level(-3.62 e V). It can therefore serve as a superior model for facile construction of functional polyolefin and soluble PTCBI polymer with ordered architecture.     

Spectral stability of periodic waves in the generalized reduced Ostrovsky equation

We consider stability of periodic travelling waves in the generalized reduced Ostrovsky equation with respect to co-periodic perturbations. Compared to the recent literature, we give a simple argument that proves spectral stability of all smooth periodic travelling waves independent of the nonlinearity power. The argument is based on the energy convexity and does not use coordinate transformations of the reduced Ostrovsky equations to the semi-linear equations of the Klein–Gordon type.     

A computational study of the electronic structure and the chemical activity of curcumin and some novel curcuminoids by density functional theory

Structural modification of curcumin represents a strategy to improve its stability, water solubility, pharmaceutical properties and bioactivity. In this context, numerous structural analogues of curcumin, including curcuminoids, have been developed. In this paper, the precise density functional theory computations were used for investigating the electronic and geometrical structure of curcumin and some of its derivatives. The chemical activity of the considered molecules was investigated with the help of the global softness and hardness concepts. Among the studied molecules, bisdemethoxycurcumin had the most chemical activity and hexahydrocurcumin had the most stable structure. Among two isomers of the curcumin, the enol isomer was found to be active.