Jin X.,Zhejiang Province Key Laboratory of Soldering and Brazing Materials and Technology |
Mao A.,Anhui University of Technology |
Mao A.,Anhui Ruital New Material Technology Co. |
Ding M.,Anhui University of Technology |
And 5 more authors.
Applied Spectroscopy | Year: 2016
Water-dispersed Cu@Ag core-shell nanoparticles (NPs) with 15 nm-diameter Cu core and 5 nm-thick Ag shell can be synthesized by a facile one-step chemical reduction at room temperature without any protective atmosphere. To obtain a homogeneous Ag coating on Cu, the influence of [Cu/Ag] molar ratio was investigated. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) confirmed that Ag formed a dense coating on the surface of Cu, and that phase-pure spherical Cu@Ag core-shell bimetallic NPs were prepared when the [Cu/Ag] molar ratio was between 1/0.5 and 1/0.75. The time dependence of ultraviolet-visible (UV-Vis) spectra and XRD patterns of six-month stored Cu@Ag NPs showed that the as-prepared Cu@Ag NPs have a long-term antioxidant activity. Also, the surface-enhanced Raman scattering (SERS) signals had a high stability and reproducibility for the substrates. Hence, the as-prepared Cu@Ag nanostructures can be used as an efficient substrate for SERS signals. © Society for Applied Spectroscopy.
Xu N.N.,Wuhan University of Science and Technology |
Li S.J.,Wuhan University of Science and Technology |
Li S.J.,Anhui Ruital New Material Technology Co. |
Li Y.B.,Wuhan University of Science and Technology |
And 4 more authors.
Advances in Applied Ceramics | Year: 2015
High voltage insulator waste (HVIW) eliminated from high voltage transmission lines was used in the preparation of porous mullite ceramics. The fabrication and characterisation of porous mullite ceramics are described. The relationship between phase transitions, sintering temperature and physicochemical properties of the porous mullite ceramics are analysed and compared. The results show that the complex properties are the best when the mass ratio of HVIW/clay is 4 : 1, the amount of pore former is 500 mL kg-1 and the sintering temperature is 1500°C, the cold crushing strength reaches 4·8 MPa. Increasing the sintering temperature could strengthen the specimens. The average pore diameter of the specimens enlarged with the increasing sintering temperature. Meanwhile, the crystalline and morphology of mullite grains advanced and the maximum grain diameter reached to 1·5 μm. This improvement was attributed to the fact that complex properties of specimens could be optimised by new formation of new mullite phase. © 2015 Institute of Materials, Minerals and Mining
Xu N.,Wuhan University of Science and Technology |
Li S.,Wuhan University of Science and Technology |
Li S.,Anhui Ruital New Material Technology Co. |
Li Y.,Wuhan University of Science and Technology |
And 4 more authors.
Ceramics International | Year: 2015
In this paper, porous ceramic aggregates were prepared by electrical insulators waste (EIW). Effects of sintering temperature and content of EIW on the aggregates' properties such as bulk density, and apparent porosity, total porosity, and cold crushing strength were investigated. With increasing sintering temperature and content of EIW, bulk density and cold crushing strength of the aggregates increased, apparent porosity and total porosity decreased. Based on these results, total porosity of specimens in group B sintered at 1200 °C is 62.0%, cold crushing strength is 35.3 N, and thermal conductivity is 0.165 W/(m K) at 300 °C. Comprehensive properties of specimens can be optimized by adjusting sintering temperature. Meanwhile, strength variation resulted from the combined effects of phase transformation and matrix densification under different sintering temperatures. © 2015 Elsevier Ltd and Techna Group S.r.l.