Papers by Keyword: Complex

Abstract: Extraction of citric acid from aqueous solutions with tertiary amine, dissolved in mixtures of kerosene and phase modifier have been studied as a function of exaction yield at different phase modifier volume fraction, temperatures, stirring speed and exaction time. The optimal experimental conditions of extraction were obtained: reaction temperature 303K, reaction time 3 min, the kerosene volume fraction 20%, and 45% 1−octanol as phase modifier, stirring speed 450rpm/min. Under these conditions, the extraction yield could reach 75%. The complex of citric acid and tertiary amine was a surfactant that makes surface tension decrease. The composition of the citric acid complex is (R₃N) · (H₃A). The formation of complex was exothermic reaction that the standard enthalpy change and standard entropy change are obtained: ΔH^θ=-10.17kJ/mol, ΔS^θ=-11.86J/(mol·K).

Abstract: Benzimidazole compounds are known to possess varied biological activities and so far various types of benzimidazole drugs have extensively been used in clinic. Benzimidazole compounds as a antibacterial agents has been a quite rapidly developing and is gradually becoming a relatively independent scientific area. In this paper we presented the recent advances of benzimidazole compounds as antibacterial agents. The perspective of the foreseeable future and potential application of benzimidazole as antibacterial agents are also presented.

Abstract: La (III) complex with apigenin was synthesized and characterized by UV, IR, ¹HNMR and thermal analysis. The scavenging activity of the complex on superoxide anion radical (O₂^-·) and hdroxyl radical (·OH) was also investigated by improved pyrogallic acid way and ortho-oxybenzoic acid way. The results show that the complex had remarkable scavenging effects on O₂^-· and ·OH, and its scavenging effect on free radicals was better than apigenin.

Abstract: The intrusion of pathogens into ballast water, not only destroys marine ecological environment, but also threatens human health. The study synthesized a new cobalt complex with a ligand of 3-pyridine-4-benzoic acid by hydrothermal synthesis method. Its structure was characterized by elemental analyzer and single crystal diffractometer, and its infrared spectroscopy, thermal stability and inhibitory activity were analyzed. The results show that the complex belongs to the monoclinic system and space group C2 / c, with unit cell parameters a = 8.2484 (9) Å, b = 10.3371 (11) Å, c = 12.2031 (14) Å, α = 89.588 (2) °, β = 87.0870 (10) °, cell volume = 982.03 (19) Å3, Z = 2, F (000) = 508, D_calc = 1.709mg/cm³, R1 = 0.0391 and wR2 = 0.0807. The asymmetric unit of the complex consists of the two Co ions, four ligand molecules and two coordinated water molecules, each center Co ions forms a hexacoordinated distorted octahedral structure. The MIC of complex for Escherichia coli, Salmonella and Vibrio parahaemolyticus in ballast water are respectively 78μg/mL, 39μg/mL and 78μg/mL, and its antimicrobial effects is better than ligands, which can be used as a novel bacteriostatic agent of ballast water.

Abstract: The paper gains a new method for the synthesis of γ-MnOOH crystals by adding ethylenediamine metal complexes under hydrothermal conditions. Study the effect of different preparation process to the reaction products .The structure and morphology of the resultant products were characterized by using XRD, SEM. The results show that the product is α-MnO₂ when did not join the ethylenediamine metal complexes and the product is γ-MnOOH when joined the ethylenediamine metal complexes in 100°C under hydrothermal conditions. The purity of the γ-MnOOH is not the same when adding different ethylenediamine metal complexes. Inorganic salts will reduce the purity of the product and a new Mn₃O₄ crystal can be prepared by increasing the reaction temperature to 180°C.

Abstract: A preparation technology, characterization and release performance of pterostilbene cyclodextrin inclusion is investigated.

Abstract: Three different ratios of double hydrophilic block copolymers poly [2-(dimethylamino) ethyl methacrylate]-b-poly(oligo(ethylene oxide) monomethyl ether methacrylate)-b-poly [2-(dimethylamino) ethyl methacrylate] (PDMAEMA-b-POEOMA-b-PDMAEMA) were synthesized by reversible addition fragmentation chain-transfer polymerization (RAFT), which was one of the controlled/living radical polymerization. The chain structure and component of such copolymers were characterized by spectroscopic studies (FTIR, 1H NMR). The interaction of PDMAEMA-b-POEOMA-b-PDMAEMA copolymers with copper sulfate and copper chloride solution was studied. It was found that the anion SO42-, Cl-1 could have an effect on the structure and coordination of the Cu(II) complexes, which were confirmed by FTIR and scanning electron micrographs (SEM).

Abstract: The complex of β-cyclodextrin (β-CD) and RC2540 dialkyl pentasulfide was synthesized and characterised by means of fourier transform infrared spectroscopy (FTIR), thermo-gravimetric analysis (TG) and scanning electron microscope (SEM). Then the friction and wear behavior of RC2540, β-CD and complex were studied by four-ball test using the mixture of PEG-600 and water as base fluid, and finally the lubrication mechanism of β-CD and the complex were analyzed using energy-dispersive X-ray spectroscopy (EDS). The experimental results revealed that the complex had formed well and had better antifriction and anti-wear property than β-CD. RC2540 in complex was released and the extreme pressure film was formed on the friction interface in the friction process. The β-CD molecules in complex were cracked into fragments, and the fragments with hydroxyl also formed lubricating film and fragments with no hydroxyl were mainly carbonized. The lubricating film of the complex had a better tribological performace due to the cooperation of the lubricating film of β-CD and extreme pressure film of RC2540.

Abstract: Preparations, Characterizations and Release Performances of Oxyresveratrol-Hydroxypropyl Cyclodextrin Inclusion and Pterostilbene-Hydroxypropyl Cyclodextrin Inclusion Are Reported.

Abstract: In view of the issue that Heat Conductivity Coefficient (HCC) value of Thick-typed Fireproofing Coating (TFC) for tunnel at elevated temperature is not unknown, which makes researchers unable to make right fireproofing design and analysis for structure, starting from composition of TFC for tunnel, regarding it as complex of insulation aggregate and adhesive material, and using series model and parallel model, formulas of HCC at elevated temperature are established. The temperature field in three specimens is calculated by above HCC value, and is compared with testing results. Analysis result shows that HCC value from series model is the most reasonable. This paper provides an effective Solution for HCC value of TFC for tunnel at elevated temperature.