Anguo Xiao

Hydrothermal synthesis of porous Co(OH)2 nanoflake array film and its supercapacitor application

Porous α-Co(OH)2 nanoflake array film is prepared by a facile hydrothermal synthesis method. The α-Co(OH)2 nanoflake array film exhibits a highly porous net-like structure composed of interconnected nanoflakes with a thickness of 15 nm. The pseudo-capacitive behaviour of the Co(OH)2 nanoflake array film is investigated by cyclic voltammograms (CV) and galvanostatic charge–discharge tests in 2 M KOH. The α-Co(OH)2 nanoflake array film exhibits high capacitances of 1017 F g − 1 at 2 A g − 1 and 890 F g − 1 at 40 A g − 1 as well as rather good cycling stability for supercapacitor application. The porous architecture is responsible for the enhancement of the electrochemical properties because it provides fast ion and electron transfer, large reaction surface area and good strain accommodation.

Recent Research Progress of Branched and Functional Branched Polyethylene Prepared Using Ni- and Pd–Based Catalysts

In this paper, the recent development of branched and functional branched polyethylene prepared using Ni- and Pd-based catalysts are reviewed. The influence of ligand species, steric effect, electronic effect and polymerization condition on branching density of resultant polymer prepared using Ni- and Pd-based catalysts is discussed. In addition, the review is also focused on functional branched polyethylene produced by copolymerization of ethylene and polar monomer and copolymerization mechanism.

Luminescence properties of Tb3+-doped borosilicate scintillating glass under UV excitation

Transparent Li₂O-BaO-La₂O₃-Al₂O₃-B₂O₃-SiO₂ glasses doped with Tb(3+) ion were prepared by high temperature melting method. Luminescence properties of Tb(3+)-doped borosilicate glasses have been investigated by transmission, excitation, emission and luminescence decay measurements. The transmission spectrum shows the glass has good transmittance in the visible region. Under the 236 nm UV excitation the intense green emission from (5)D₄ level is observed in Tb(3+)-doped borosilicate glass, comparable in intensity to the violet-blue emission starting from the (5)D₃ level. The green emission intensity of Tb(3+) ion firstly increases and then decreases with the decreasing B₂O₃/SiO₂ ratio in glass matrix. (5)D₄→(7)FJ (J=6, 5, 4 and 3) transitions of Tb(3+) ion in borosilicate glass are greatly enhanced with increasing concentration of Tb(3+) through the cross relaxation [Tb(3+) ((5)D₃)+Tb(3+) ((7)F6)→Tb(3+) ((5)D₄)+Tb(3+) ((7)F₀)] between two Tb(3+) ions. Luminescence decay time of 2.13 ms is obtained for the emission transitions starting from (5)D₄ level in 2.5Li₂O-20BaO-20La₂O₃-2.5Al₂O₃-20B₂O₃-35SiO₂-0.5Tb₄O₇ glass. The results show that Tb(3+)-doped borosilicate glasses would be potential candidates for scintillating material for static X-ray imaging.

Mechanical Properties of Elastomeric Terpolymer Composites Containing Carbon Nanotubes

Nanocomposites were obtained by mixing terpolymer and carbon nanotubes (CNTs) in a twin-screw extruder at 135–155°C. The results indicated that increasing the amount of PSt, the molecular weight of PSt macromonomer of terpolymers and CNTs charged resulted in improving the tensile strength and modulus at 300% elongation of nanocomposites.

Synthesis, Electrochemical Behaviors and Anion Recognition of A Novel Star-[Polystyrene-b-poly(ferrocenyloxy ethyl acrylate)]6 with Hexafunctional Cyclotriphosphazene Core

A novel star-[polystyrene-b-poly(ferrocenyloxy ethyl acryl ate)]6 with hexa- functional cyclotriphosphazene core (star-(PS-b-PFcEA)6) was synthesized by atom -transfer radical polymerization(ATRP) and its electrochemical behaviors and anion recognition was investigated through CV. The results indicated that increasing of molecular weight resulted in obvious decreasing of reduction peak potential Epc, and the oxidation peak potential Epa kept comparatively stable. Moreover, when titrating anion into polymer solution, Epc increased while Epa reduced evidently, which suggested that star-(PS-b-PFcEA)6 provided with high anion recognition capacity of .

Mechanical Properties of Nanocomposites Prepared Using Elastomeric Terpolymer and Nano-SiO2

Nanocomposites were obtained by mixing elastomeric terpolymer and nano-SiO2 in double-screw extruder at 130–150°C, in which elastomeric terpolymer was prepared by terpolymerization of poly(methyl methacrylate (PMMA) macromonomer, butyl acrylate (BA), and acrylic acid (AA) in benzene using azobisisobutyronitrile (AIBN) as initiator. The results indicated that increasing the amount of PMMA, the molecular weight of PMMA and terpolymers as well as the content of carboxylic acid were favorable to increase the mechanical properties of nanocomposites. In addition, the tensile strength and the modulus at 300% elongation of nanocomposites reach to a maximum while the mass ratio of nano-SiO2 to terpolymer is 3%.

Luminescence and energy transfer of Tb3 +–doped BaO–Gd2O3–Al2O3–B2O3–SiO2 glasses

Transparent Tb3+-doped BaO-Gd2O3-Al2O3-B2O3-SiO2 glasses with the greater than 4g/cm3 were prepared by high temperature melting method and its luminescent properties have been investigated by measured UV-vis transmission, excitation, emission and luminescence decay spectra. The transmission spectrum shows there are three weak absorption bands locate at about 312, 378 and 484nm in the glasses and it has good transmittance in the visible spectrum region. Intense green emission can be observed under UV excitation. The effective energy transfer from Gd3+ ion to Tb3+ ion could occur and sensitize the luminescence of Tb3+ ion. The green emission intensity of Tb3+ ion could change with the increasing SiO2/B2O3 ratio in the borosilicate glass matrix. With the increasing concentration of Tb3+ ion, 5D4→7FJ transitions could be enhanced through the cross relaxation between the two nearby Tb3+ ions. Luminescence decay time of 2.12ms from 546nm emission is obtained. The results indicate that Tb3+-doped BaO-Gd2O3-Al2O3-B2O3-SiO2 glasses would be potential scintillating material for applications in X-ray imaging.