Formation of the Inclusion Complex of Orange II with β-Cyclodextrin and Its Photostability

Inclusion complex of Orange II with β-Cyclodextrin (β-CD) and the anti-photolysis effect under UV-light were investigated. The molar ratio of inclusion complex of β-Cyclodextrin and Orange Ⅱ is 1∶1. The formation constant K=1.236×103 L/mol was determined by the UV and Fluorescence spectra respectively, which was quite in accordance with the calculation with a modified Benesi-Hildbrand equation. The inclusion complex was characterized by the IR spectra and the molar ratio of inclusion complex is 1∶1 too. The formation constant K=1.266×103 L/mol was determined by 1 H NMR analysis and was nearly the same by UV and fluorescence spectra. The photocatalytic decolorization rate of Orange Ⅱ solutions containing β-CD and TiO2 was smaller by 51.9% than that of the Orange Ⅱ solutions only containing TiO2, while in the case of direct photolysis of Orange Ⅱ solutions, β-CD can lower the photolysis rate by 48.1% under UV-light. This result indicates β-CD can inhibit the photolysis and photocatalytic decolorization of Orange Ⅱ under UV-light. The β-CD inclusion complex was found to be persistent to UV-light photolysis.     

Synthesis of PbS–K2La2Ti3O10 composite and its photocatalytic activity for hydrogen production

Photocatalyst, lead sulfide (PbS )-intercalated layer perovskite-type compound (K2La2Ti3O10), was synthesized via ion-exchange reaction, butylamine pillaring and sulfuration processes under the assistance of the microwave irradiation. The structure of the photoc atalysts was determined by means of powder X-ray diffraction, scanning electron microscope, ultraviolet- visible diffuse reflection spectra and photoluminescence measu rement. And the photocatalytic activity of the composite compound for hydrogen production was also investigated. The experimental results showed that the intercalation of PbS in the layered space of K2La2Ti3O10 greatly improved the absorption edge and the photocatalytic activity. Hydrogen production of the PbS–K2La2Ti3O10 was 127.19 mmol/(g cat) after 3 h irradiation of ultraviolet light.     

Multiferroic and magnetoelectric properties of La0.1Ba0.9Fe12O19 ceramics

La0.1Ba0.9Fe12O19 powders with similar hexagonal crystal structure to Ba Fe12O19 have been successfully synthesized using polymer precursor method. The powders were suppressed into pellets, which were sintered into ceramics at 1,300 °C for 1 h. The structure and morphology of the ceramics have been determined by X-ray diffraction（XRD） and field emission scanning electron microscopy（FESEM）. Clear electric hysteresis loops upon different amplitude of external fields indicates that La0.1Ba0.9Fe12O19 is a kind of possible ferroelectric compound. The maximum remnant polarization of La0.1Ba0.9Fe12O19 ceramic is estimated to be ＊9.6 l C/cm2. The Fe O6 octahedron in its perovskite-like hexagonal unit cell as well as the shift of Fe3？off the center of octahedron are proposed to be the origin of electric polarization in La0.1Ba0.9Fe12O19. Simultaneous occurrence of large ferroelectricity and strong ferromagnetism has been observed in La0.1Ba0.9Fe12O19 ceramics. More interestingly, this compound demonstrates electronic polarization behavior being actuated by an applied magnetic field, indicating the existence of magnetoelectric（ME） coupling effect in the La0.1Ba0.9Fe12O19 ceramics. Our results may lead to new device applications such as magnetically recorded ferroelectric memory.     

Thermodynamic analysis and preparation of β-SiC/ZrO2 composites

A predominance area diagram for the Zr-Si-C-O system at 1773 K was plotted according to correlative thermodynamic data. β-SiC/ZrO₂ composites were prepared based on the phase diagram by carbothermal reduction of zircon (ZrSiO₄) in argon atmosphere. Zircon and carbon black were mixed according to the C/ZrSiO₄ mass ratio of 0.2, and with 0, 1wt% and 2wt% extra addition of La₂O₃. Phase evolution of the mixture was investigated at 1723-1803 K by X-ray powder diffraction, and the microstructure of the product prepared at 1803 K for 4 h was examined by scanning electronic microscope. The results show that the decomposition of ZrSiO₄ and the formation of β-SIC can be promoted by increasing the heating temperature and adding La₂O₃. The β-SiC/ZrO₂ composites can be prepared at 1803 K for 4 h in a mixture of zircon, carbon black and La₂O₃, and the contents of β-SIC and m-ZrO₂ in the product sample with 2wt% La₂O₃ reach the highest values of 10.8wt% and 89.2wt%, respectively. The crystal size of the products is about 200 nm.     

La2O3–Al2O3 –SiO2 glass-infiltrated 3Y-TZP all-ceramic composite for the dental restora tive application

The 3 mol% yttria stabilized tetragonal zirconia polycrystals (3Y-TZP) powder had three particle size distributions, while the fine one was lower than 100 nm. The 3Y-TZP compact was prepared by dry-pressing under pressures ranged from 10 to 30 MPa and then presintered at 1250°C for 2 h. The matrix dry-pressed under the pressure of 20 MPa had a porosity of 16.7% and could be easily processed by computer aided design and computer aided manufacturing (CAD/CAM), and which had been infiltrated by the La2O3–Al2O3–SiO2 glass at 1200°C for 4 h. The flexural strength and fracture toughness of the composite were 710.7 MPa and 6.51 MPa m^1/2, respectively. The low shrinkage (0.3%) of the composite can satisfy the net-shape fabrication standard. XRD results illustrated that zirconia in the La2O3–Al2O3–SiO2 glass-infiltrated 3Y-TZP all-ceramic composite was mainly in the tetragonal phase. SEM and EDS results indicated that the pores of the matrix were almost filled by the La2O3–Al2O3 –SiO2 glass     

Photoelectrochemical synergetic degradation of Acid Orange II with TiO2 modified β-PbO2 electrode

Electrochemically assisted photocatalysis is an effective approach to improve photocatalytic efficiency. In this paper, modified β-PbO2 electrode was prepared by TiO2 co-deposition and characterized by SEM and XRD. Then 2.0g TiO2 modified β-PbO2 electrode (2.0 g TiO2 involved in the 200 mL co-deposition solution) was used in electrochemically assisted photocatalytic degradation of Acid Orange II and the influence of initial pH values was investigated when the potential applied across the electrodes was 1.5 V. When the potential applied was 2.5 V, the difference of the degradation process and the final products were studied. The results indicated that 2.0 g TiO2 modified β-PbO2 electrode was different from the unmodified one in that the β-PbO2 crystals became finer and the electrode became more compact and more uniform. The synergetic effect in electrochemically assisted photocatalytic degradation of Acid Orange Ⅱ was observed and degradation efficiency and TOC removal were the highest at initial solution pH 2.0. By UV-visible spectral analysis, it was proved that photoelectrochemical synergetic degradation of Acid Orange Ⅱ went through the step of producing main product maleic acid for the solution at the initial pH 2.0 within 2 h, but the degradation was slow for the solution at the initial pH 12.0.     

The development of Bi Fe O3-based ceramics

The multiferroic properties of Bi Fe O3-based ceramics were improved through optimizing their sintering method and doping with certain rare earth elements in pure Bi Fe O3. Some methods, especially liquid-phase sintering method has largely decreased the densities of oxygen vacancies and Fe2in Bi Fe O3-based ceramics, and thus their resistivity became high enough to measure the saturated polarization and the large piezoelectric d33 coefficient under the high electric field of [150 k V/cm. Besides,multiferroic properties were improved through the rare earth elements’ doping in pure Bi Fe O3. Magnetization commonly increases with the proportional increase of Nd,La, Sm and Dy contents up to ＊30 %, while ferroelectric phase can transform to paraelectric phase at a certain proportion. An improved magnetoelectric coupling was often observed at ferroelectric phase with a relatively large proportion. Besides, an enhanced piezoelectric coefficient is expected in Bi Fe O3-based ceramics with morphotropic phase boundaries as they are already observed in thin epitaxial Bi Fe O3 films.     

Microstru cture and oxygen storage capacity of Sr-modified Pt/CeO2 –ZrO2catalysts

Strontium was introduced into CeO2–ZrO2 mixed oxides (CZ) by doping and impreg-nation metho ds, and then Pt was impregnated on the Sr-modifie d CZ to obtain the catalysts. X-ray diffraction (XRD), X-photon spectra (XPS), high-resolution transmission electronic microscopy (HRTEM) and H2 temperature programmed reduction (TPR) were carried out to characterize the micro-structure and reducibility of catalysts. The oxygen storage capacity (OSC) was evaluated with CO serving as probe gas. The results showed that the incorporation of Sr₂₊ in the lattice of CZ could promote the OSC properties by increasing the structure defects and enhancing the diffusion rate of oxygen from bulk to surface. For the Sr-impregnated sample, the strong metal–support interaction (SMSI) between Pt and CZ was interrupted, since Sr covered parti al surface Ce species. Such interruption retarded the back-spillover effect occurring at the Pt/Ce interface at low temperature, resulting in the loss of OSC. Meanwhile, it was found that a part of impregnated Sr₂₊ could partially diffuse from the surface to the inner atomic layers of CZ and partially incorporated in the lattice during the calcination. The OSC performance of Sr-impregnated sample therefore climbed remarkably with the rise of temperature.     

Effect of rolling technologies on the properties of Pb?0.06wt%Ca?1.2wt%Sn alloy anodes during copper electrowinning

The objective of this work was to study the effect of different rolling technologies on the properties of Pb?0.06wt%Ca?1.2wt%Sn anodes during copper electrowinning and to determine the relationship between the properties of the anodes and rolling techniques during copper electrowinning. The anode process was investigated via anodic polarization curves, cyclic voltammetry curves, electrochemical impedance spectra, and corrosion tests. The microscopic morphology and phase composition of the anodic oxide layers were observed by scanning electron microscopy and X-ray diffraction, respectively. Observable variations in the electrocatalytic activity and reaction kinetics of anodes during electrowinning indicated that the electrochemical behavior of the anodes was strongly affected by the rolling technology. An increase in the rolling number tended to decrease the oxygen evolution overpotential and the corrosion rate of the anodes. These trends are contrary to that of the apparent exchange current density. Furthermore, the intensities of diffraction peaks associated with Pb O, Pb Ox, and α-Pb O2 tended to increase with increasing rolling number. In addition, the rolled anodes exhibited a more uniform microstructure. Compared with one-way rolled anodes, the eight-time cross rolled anodes exhibited better electrocatalytic activity and improved corrosion resistance.     

H2O/CO2 co-electrolysis in solid oxide electrolysis cells

A solid oxide electrolysis cell （SOEC） is an environmental-friendly device which can convert electric energy into chemical energy with high efficiency. In this paper, the progress on structure and operational principle of an SOEC for co-electrolyzing H2O and CO2 to generate syngas was reviewed. The recent development of high temperature H2O/CO2 co-electrolysis from solid oxide single electrolysis cell was introduced. Also investigated was H2O/CO2 co-electrolysis research using hydrogen electrode-supported nickel （Ni）-yttria-stabilized zirconia （YSZ）/YSZ/Sr-doped LaMnO3 （LSM）-YSZ cells in our group. With 50 % H2O, 15.6 % H2 and 34.4 % CO2 inlet gas to Ni- YSZ electrode, polarization curves （I- U curves） and electrochemical impedance spectra （EIS） were measured at 800 ℃ and 900 ℃. Long-term durability of electrolysis was carried out with the same inlet gas at 900 ℃ and 0.2 A/cm2. In addition, the improvement of structure and development of novel materials for increasing the electrolysis efficiency of SOECs were put forward as well.     

Cathodic reaction mechanisms in CO2 corrosion of low-Cr steels

The cathodic reaction mechanisms in CO₂ corrosion of low-Cr steels were investigated by potentiodynamic polarization and galvanostatic measurements. Distinct but different dominant cathodic reactions were observed at different pH levels. At the higher pH level (pH >~5), H₂CO₃ reduction was the dominant cathodic reaction. The reaction was under activation control. At the lower pH level (pH <~3.5), H+ reduction became the dominant one and the reaction was under diffusion control. In the intermediate area, there was a transition region leading from one cathodic reaction to another. The measured electrochemical impedance spectrum corresponded to the proposed cathodic reaction mechanisms.     

Synthesis and Property Studies of Transparent Resins Containing Rare Earth Complex Eu(Ⅲ) (TTA)_2(MA)_2 Phen·H_2O

A new rare earth complex Eu(Ⅲ)(TTA)2(MA)2Phen·H2O was synthesized and characterized by element analysis, FTIR, UV, thermal analysis, and fluorescence spectra. The strong fluorescence and high thermal stability of Eu(Ⅲ)(TTA)2(MA)2Phen·H2O were used to modify resin. The copolymer containing europium was prepared by copolymerization of Eu(Ⅲ) and styrene/α-methylacrylic acid, and characterized by FTIR and fluorescence spectra. The fluorescence spectra showed that the copolymer was a sort of materials with good ...     

Novel approaches to produce Al2O3– TiC/TiCN– Fecomposite powders directly from ilmenite

Al2O3 –TiC/TiCN–Fe composite powders were successfully prepared directly from ilmenite at 1300–1400℃.The effects of Al/C ratio,sintering atmosphere,and reaction temperature and time on the reaction products were investigated.Results showed that the nitrogen atmosphere was bene cial to the reduction of ilmenite and the formation of Al2O3 –TiC/TiCN–Fe composite powders.When the reaction temperature was between 600 and 1100℃,the intermediate products,TiO2,Ti3O5 and Ti4O7 were found,which changed to TiC or TiCN at higher temperature.Al/C ratio was found to affect the reaction process and synthesis products.When Al addition was 0.5 mol,the Al2O3 phase did not appear.The content of carbon in TiCN rose when the reaction temperature was increased.     

Cu-Zn-Al2O3 nanocomposites:study of microstructure,corrosion,and wear properties

Alumina nanoparticles were added to a Cu-Zn alloy to investigate their effect on the microstructural, tribological, and corrosion properties of the prepared alloys. Alloying was performed using a mixture of copper and zinc powders with 0vol% and 5vol% of α-Al nanopowder in a satellite ball mill. The results showed that the Cu-Zn solid solution formed after 18 h of mechanical alloying. The mechanically alloyed powder was compacted followed by sintering of the obtained green compacts at 750℃ for 30 min. Alumina nanoparticles were uniformly distributed in the matrix of the Cu-Zn alloy. The tribological properties were evaluated by pin-on-disk wear tests, which revealed that, upon the addition of alumina nanoparticles, the coefficient of friction and the wear rate were reduced to 20% and 40%, respectively. The corrosion properties of the samples exposed to a 3.5wt% NaCl solution were studied using the immersion and potentiodynamic polarization methods, which revealed that the addition of alumina nanoparticles reduced the corrosion current of the nanocomposite by 90%.     

Etching mechanism of barium strontium titanate （BST） thin films in CHF_3/Ar plasma

Reactive ion etching was used to etch barium strontium titanate thin films in a CHF3/Ar plasma.BST surfaces before and after etching were analyzed by X-ray photoelectron spectroscopy to investigate the reaction ion etching mechanism,and chemical reactions had occurred between the F plasma and the Ba,Sr and Ti metal species.Fluorides of these metals were formed and remained on the surface during the etching process.Ti was almost completely removed because the TiF4 by-product is volatile.Minor quantities of Ti?F could still be detected by narrow scan X-ray photoelectron spectra,and Ti?F was thought to be present in the form of a metal-oxy-fluoride.These species were investigated from O1s spectra,and a fluoride-rich surface was formed during etching.BaF2 and SrF2 residues were difficult to remove because of their high boiling point.The etching rate was limited to 12.86 nm/min.C?F polymers were not found on the surface,indicating that the removal of BaF2 and SrF2 was important for further etching.A 1-min Ar/15 plasma physical sputtering was carried out for every 4 min of surface etching,which effectively removed remaining surface residue.Sequential chemical reaction and sputtered etching is an effective etching method for barium strontium titanate films.     

The synthesis and properties study of 6,13-diphenylpentacene

6,13-diphenylpentacene（DPP） was synthesized by 6,13-pentacenequinone and the Grignard reagent with the SnCl2/HCl as the reducing agent. It was detected by ^1H NMR, infrared spectra, X-ray diffraction （XRD）, UV-visible spectra and fluorescence spectra. Substitution with phenyl at the C-6 and C-13 positions of pentacene leads to phenomenal enhancement in solubility and a little enhancement in photooxidative stability. XRD results showed that the pattern of 6,13-diphenylpentacene was different from the patterns of pentacene and 6,13-pentacenequinone. UV-Visible spectra showed that the λmax of DPP in HCCl3 was 600 nm. The fluorescence spectra showed that DPP emitted purple （430 nm） and red （612 nm） when excited by UV, while only emitted red when excited by visible light. But it is still susceptible to photooxidation. The photooxidation product of DPP was also studied.     

Synthesis and formation mechanism of micro/nano flower-like MgCO3·5H2O

Micro/nano magnesium carbonate pentahydrate（MgCO3 ·5H2 O） with flower-like morphology was synthesized using magnesite as a substrate and potassium dihydrogen phosphate as an additive. The synthesized samples were characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry and differential scanning calorimetry. The influence of pyrolysis time on crystal morphology was explored. The formation mechanism was investigated on the basis of the characterized results and the crystal structure of MgCO3 ·5H2 O. The results showed that the flower-like MgCO3 ·5H2 O was 1.5-3.0 μm in length and 100-500 nm in diameter and was successfully obtained with a pyrolysis time of 30 min. The formation mechanism of flower-like MgCO3 ·5H2 O is suggested to be the selective adsorption of potassium dihydrogen phosphate on the surface. The process of flower-like crystal growth is as follows： amorphous nanoparticles formation, acicular and rod monocrystal formation, flower-like monocrystal formation, and flower-like polymers（MgCO3 ·5H2 O） crystallization. In the MgCO3 ·5H2 O crystal, the magnesium ion presents two different octahedral coordinations corresponding to2 26 Mg（H O）＋and2 2 2 4 23 [Mg（H O）（CO） ]--, and the chemical formula of the crystal is2 2 6 2 4 23 Mg（H O） Mg（H O）（CO）2.     

Mechanism of Cathode Process of B(Ⅲ) in LiF-NaF-KBF4 Melt by Electrochemical Titration Technique

The mechanism of cathode process of B(Ⅲ) at molybdenum and platinum electrodes in LiF-NaF-KBF₄ melt was studied and the transferred electron number of the reaction was calculated by means of cyclic voltammetry.The effect of adsorption of electroactive component on the electrochemical response (e.g., the voltammetric i─E curves) was analyzed and discussed. The "electrochemical spectra" for linear sweep voltammetry was used to elucidate the electrode reaction accompanied by a following transform process. The results show that the reduction of B(Ⅲ) to B(0) proceeds in reversible one step three-electron reaction and the cathode process of B(Ⅲ) is affected by product adsorbed strongly at the electrode surface. It is assumed that the reduction and deposition of B(Ⅲ) at molybdenum and platinum electrodes proceed in two kinds of mechanism: (1) B(Ⅲ)+ 3e = B_ads→ B (surface diffusion deposition mechanism) and (2) B(Ⅲ) + 3e = B (direct deposition mechanism).     

A.C. conductivity and relaxation dynamics in zinc–borate glasses

The frequency-dependent dielectric dispersion of ZnO–Na2O–Al2O3–B2O3(in mol%) glass prepared by the melt quenching technique is investigated in the temperatur e ranges from room temperature to 420 K. Dielectric relaxation has been analyzed based on the behavior of electric modulus behavior. An analysis of the real and imaginary parts of dielectric is performed assuming the ideal Debye behavior as confirmed by Cole–Cole plot. The activation energy associated with the dielectric relaxation determined from the electric modulus spectra was found to be 1.863 eV, which is close to that the activation energy for d.c. conductivity (1.871 eV), indicating the similar nature of relaxation and conductivity.     

Resonance-enhanced multiphoton ionization spectroscopy on the B′2Σ+ and B2Π states of NS

Resonance-enhanced multiphoton ionization （REMPI） spectra of N^32S and N^34S have been recorded in the range of 35700-40200 cm^-1. The radical was generated by a pulsed dc discharge of a mixture of SF6 and N2 under a supersonic free jet condition. All the 16 observed bands of N^32S radicals have been assigned, among which 12 bands belong to three transition progressions （v′=0-4, 0）, （v′=1-4, 1） and （v′=2-4, 2） from the X^2П ground state to the B′^2∑^＋ upper state and the rest correspond to （9, 0）, （10, 0）, （11, 0） and （12, 0） bands of B^2П-X^2П transition, respectively. Analysis of the rotationally resolved spectra yields exhaustive spectroscopic constants of both the X^2П ground state and the B′^2∑^＋ excited state. The electronic transition bands of the isotopic molecule N^34S have been rotationally analyzed for the first time and the rotational constants of the ground and upper states have been determined simultaneously.