Abstract: The metastable phase equilibrium in the ternary system containing potassium, lithium and chloride ions was studied at 298.15 K using an isothermal evaporation method. The solubility, density and refractive index of the equilibrated solution were measured. The crystalloid forms of the solid phase were determined using a schreinermarks wet residue method. On the basis of the experimental data, the metastable equilibrium phase diagram and the physicochemical properties vs composition in the ternary system at 298.15 K were plotted. The experimental results show that this system is of a simple eutectic type system, no double salt or solid solution formed at 298.15 K. The phase diagram consists of one invariant point, two uninvariant curves, and two crystallization regions. The crystallization regions correspond to potassium chloride (KCl) and lithium chloride monohydrate (LiCl·H2O), respectively. Salt KCl has the largest crystallization field, whereas salt LiCl·H2O has the smallest crystallization field. Salt LiCl has strong salting-out effect on salt KCl.
Abstract: In this article, the esterification of methanol with maleic anhydride has been studied. The focus was on the production kinetics of monomethyl maleate. A three neck flask with a flux condenser and stirrer was taken as a batch reactor. The temperature was maintained and controlled by a thermostat. Data of concentration and time were collected by monitoring the change of the total acid. The production rate equation of monomethyl maleate was obtained through analyzing the data, which is .
Abstract: The effects of different temperatures on catalytic hydrolysis of polyethylene terephthalate(PET) by zinc sulfate as a catalyst under microwave irradiation were studied, and in the meantime, the relation between the depolymerization rate of PET and the yield of terephthalic acid(TPA) under the same temperature was investigated. The results suggested that the reaction temperature was an important influencing factor for the depolymerization reaction of PET, and the concentration of depolymerization product TPA and the depolymerization rate of PET became coherence under the same temperature.
Abstract: A bismuth diamyl-dithiocarbamate additive was synthesized. A four-ball tester was used to evaluate the tribological performance of the additive in mineral oil, and compared with same types of metal additives. The results show that it exhibits better load-carrying capacities than said organic metal additives. The surface analytical tools such as X-ray photoelectron spectrometer (XPS) and Scanning electron microscopy (SEM) were used to investigate the topography, the compositions contents and the depth profile of some typical elements on the rubbing surface of worn scar. Smooth topography of worn scar further confirms that the additive showed good antiwear capacities, the results of X-ray photoelectron spectrometer and X-Ray Energy Dispersive Spectroscopy analyses indicated that tribochemical mixed protective films consists of bismuth compounds, sulfides, sulphates were formed on the rubbing surface, which contribute to improve the tribological properties of lubricants. Particularly, a large amounts of bismuth atoms play an important role in improving antiwear properties of oils.
Abstract: To obtain attractive properties, such as increased resistance to moisture absorption, low dielectric constant and low dielectric loss, the novel bismaleimide, viz. 2,7-bis(4-maleimidophenoxy) naphthalene (BMPN), and dicyanate ester, viz. 2,7-dihydroxynaphthalene dicyanate (DNCY), containing naphthalene ring and ether linkages, have been synthesized. The cure process of the blends including of 0.11mmol/mol Fe(AcAc)3 and 2% nonylphenol is characterized by in-situ FTIR. The result obtained from in-situ FTIR spectra of cured resin illuminates that the cure reaction is homo-polymerized respectively at this condition for the mixtures of B1C1. Interlaced network patterns are seen obviously and no visible phase separation could be detected in the region for IPNs BT resin by SEM. The structure of IPNs can be formed for the blends of BMPN and DNCY containing 0.11 mmol/mol Fe(AcAc)3 and 2% nonylphenol, which is tested by in-situ FTIR and SEM methods. The glass fiber reinforced composites for this blends are made and their properties are studied. This composites show good flexural property, low dielectric constants ( Dk ) and low moisture absorption.
Abstract: Nanoscale lignin was successfully prepared with a supercritical antisolvent (SAS) apparatus using acetone as a solvent and superciritical carbon dioxide as an antisolvent. Four factors were studied and optimized by a four-level orthogonal array design (OAD). According to analysis of variance, precipitation pressure had a significant effect on mean particle size. The optimal conditions are as follows: precipitation temperature 35 °C, precipitation pressure 30 MPa, temperature difference +10 °C and concentration of lignin solution 0.5 mg/mL. The micronized lignin under the optimal conditions was characterized by Scanning Electron Microscopy (SEM), Fourier-transform Infrared Spectroscopy (FTIR), Dynamic Light Scattering (DLS) and X-Ray Diffraction (XRD) analyses. The results showed the mean particle size of micronized lignin was 0.144 ± 0.03 μm and had no degradation. The solubility of micronized lignin was improved significantly in distilled water.
Abstract: Pt/K2La2Ti3O10 was prepared by impregnating K2La2Ti3O10 into H2PtCl6 solution. The structure of the photocatalyst was studied by means of XRD, UV-Vis spectroscopy and XPS. And the photocatalytic activities of the samples were examined in a Pyrex reaction cell by splitting methanol solution. The result revealed that Pt/K2La2Ti3O10 photocatalyst showed much higher activity than pure K2La2Ti3O10 and kept a high photocatalytic activity even after 120 hours of illumination. XPS showed that the valence state of Pt was reduced from Pt to Pt0 during the illumination.
Abstract: The mCMC/TiO2-Oxine/mCS bipolar membrane (BPM) was prepared by carboxymethyl cellulose (CMC) as an anodic layer and chitosan (CS) as a cathodic layer modified by Cr3+ and glutaraldehyde as linking reagents, respectively. The Nano-TiO2 modified with the photosensitizer oxine was taken as a photocatalytic interlayer to enhance the water splitting in the interlayer of the BPM. The mCMC/TiO2-Oxine/mCS BPM shows a sandwich composition, and exhibited an excellent hydrophilic performance, lower impedance and working voltage. When the working current density is as high as 120 mA • cm-2, the working voltage is as low as 5.0 V with UV irradiation.
Abstract: TiO2 and different contents Fe3+-doped TiO2 thin films were successfully obtained on microscope glass slides by Sol-Gel method. Then the photocatalytic activities of the samples were evaluated by the degradation of Rhodamine B dye solution. The effects of both annealing temperatures and Fe3+ contents on the photocatalytic activities of TiO2 thin films were examined. The results indicated that the sample with an atomic ratio of Ti:Fe=7:3 annealed at 500°C had a higher photocatalytic activity.
Abstract: Rate equation of non-isothermal kinetics of solid decomposition involving the factors of the pressure of gaseous product, the equilibrium pressure, temperature and structure parameters of solid is deduced according to the model of the diffusion of gaseous product. A validity function in the rate equation of non-isothermal kinetics is defined which represents the influence of these factors on the diffusion rate. The effect of the validity function on the diffusion rate are studied, based on the results of thermal analysis of decomposition of calcium carbonate at different heating rates. It is shown that it is possible to improve the validity of the rate equation of non-isothermal kinetics if the effect is taken into account.