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Zhou D.,Xian Jiaotong University | Zhou D.,State Key Laboratory of Processing for Non Ferrous Metal and Featured Materials | Pang L.-X.,Xian Technological University | Xie H.-D.,Xian University of Architecture and Technology | And 6 more authors.
European Journal of Inorganic Chemistry | Year: 2014

A new microwave dielectric (AgBi)0.5WO4 ceramic with an ultralow firing temperature was prepared by the solid-state reaction method. (AgBi)0.5WO4 can be obtained as a dense single-phase bulk material with a calcination temperature of 500 °C and sintering temperatures of ca. 580 °C. The material has a microwave relative permittivity of ca. 35.9, a Qf value of ca. 13000 GHz, and a negative temperature coefficient of -69 ppm/°C at 7.5 GHz. The crystal structure of (AgBi)0.5WO 4 was determined by a combination of X-ray and transmission electron microscopy (TEM) diffraction analysis. The compound crystallizes in the monoclinic C12/m1 (no. 12) space group with the lattice parameters a = 10.1330(8) Å, b = 11.0013(0) Å, c = 7.2756(4) Å, and β = 127.712(3)°. From an X-ray diffraction analysis, the (Ag 0.5Bi0.5)WO4 ceramic reacts with silver after heat treatment at 560 °C to form new compounds, namely, Bi 2WO6 and Ag2WO4. However, the (AgBi)0.5WO4 ceramic is chemically compatible with aluminum powder at 600 °C as an alternative cofired electrode material. All the results suggest that (AgBi)0.5WO4 ceramic is a promising new candidate material for ultralow-temperature cofired ceramic (ULTCC) technology. (AgBi)0.5WO4 can be obtained as a dense single-phase bulk material with sintering temperatures of ca. 580 °C. The material has a microwave relative permittivity of ca. 35.9, a Qf value of ca. 13000 GHz, and a negative temperature coefficient of -69 ppm/°C at 7.5 GHz. It is chemically compatible with aluminum powder at 600 °C as an alternative cofired electrode material. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Lv J.,Key Laboratory of New Processing Technology for Nonferrous Metals and Materials | Lv J.,State Key Laboratory of Processing for Non Ferrous Metal and Featured Materials | Lv J.,Guilin University of Technology | Zeng D.,Guilin University of Technology | And 2 more authors.
Advances in Polymer Technology | Year: 2015

In this paper, sisal fiber cellulose microcrystal (SFCM) was prepared by the sulfate pulping method, and sisal fiber cellulose microcrystal/unsaturated polyester (SFCM/UP) in situ resin was polymerized. Furthermore, the SFCM/UP composite was prepared by rolling and molding techniques. Effects of SFCM content on mechanical and wear properties of the UP composites were studied. Structure and properties of the in situ SFCM/UP resin and its composites were characterized by using Fourier transform infrared, polarized optical microscopy, thermogravimetric analysis, scanning electron microscopy, and other methods. The results showed that the addition of SFCM by in situ polymerization significantly improves the thermal stability of UP: The decomposition temperature (Td5) of SFCM/UP in situ resin, at thermal weight loss of 5%, is increased by 16°C compared to that of the pure UP resin. On a condition that the SFCM content was 2%, the impact strength, flexural strength, and flexural modulus of SFCM/UP composites are higher than those of UP composites by 41.08%, 52.52%, and 32.31%, respectively. Moreover, the addition of SFCM significantly enhances the wear properties of unsaturated polyester composite at 200°C; the volume wear rate of SFCM/UP composite is lower than that of UP composites by 64%, indicating SFCM could significantly strengthen and toughen UP composites. © 2014 Wiley Periodicals, Inc. Source


Wang W.,Guilin University of Technology | Chen N.,State Key Laboratory of Processing for Non Ferrous Metal and Featured Materials | Chen N.,Guilin University of Technology | Li Q.,Guilin University of Technology | And 3 more authors.
Key Engineering Materials | Year: 2014

The plane surface energy of the mullite crystals (001), (010), (100) and (-100) is comparative calculated by using first-principles plane-wave pseudopotential method and the open hydrothermal system preparing mullite phase crystal test conditions. Also the plane growth habits can be predicted according to the results. The result shows that: the descending order of the mullite crystal surface energy is: E(001) > E(010) > E(-100) > E(100). On the basis of Cune-Woolf principle, the surface energy of mullite crystals (001) surface is the maximum and growth rate is the fastest. Thus the (001) crystal face is growth surface habits of mullite phase crystal. Crystal growth morphology mostly extends in one direction. © (2015) Trans Tech Publications, Switzerland. Source


Zhang L.-Y.,Guangxi University | Zhang L.-Y.,State Key Laboratory of Processing for Non Ferrous Metal and Featured Materials | Cai S.-Y.,Guangxi University | Mo J.-H.,State Key Laboratory of Processing for Non Ferrous Metal and Featured Materials | And 5 more authors.
Materials and Manufacturing Processes | Year: 2015

Preparation of H3PW12O40-TiO2/bentonite, a new photocatalytic composite material used in wastewater treatment, by a sol-gel and intercalation process has been investigated. Effects of most significant parameters in the manufacturing process on the photocatalytic activity of H3PW12O40-TiO2/bentonite were explored. The optimum values of parameters were as follows: calcination temperature was 200°C; mass ratio of TiO2 to bentonite () was 1:1; molar ratio of H3PW12O40 to TiO2 (MHPW/MTiO2) was 0.5:100; and intercalation time was 3 h. H3PW12O40-TiO2/bentonite had good photon absorption performance and high photocatalytic activity. The possible mechanism of enhanced photocatalytic activity of H3PW12O40-TiO2/bentonite in wastewater treatment was proposed. © 2015 Copyright © Taylor & Francis Group, LLC. Source


He M.,Guilin University of Technology | He X.-J.,Guilin University of Technology | Wang L.-J.,Key Laboratory of New Processing Technology for Nonferrous Metals and Materials | Wang L.-J.,State Key Laboratory of Processing for Non Ferrous Metal and Featured Materials | Xie X.-L.,Guilin University of Technology
Advanced Materials Research | Year: 2013

Organic-LDHs was prepared by three methods including co-precipitation, ionexchange and roast reduction process using Lauryl alcohol phosphoric acid ester potassium(MAPK) asmodifier.Polypropylene(PP)/Organically-modified layered double hydroxides(LDH) was prepared by the melt blending method. The structures and morphologies of composites were characterized by X-ray diffraction and TEM. TGA, cone calorimeter, limiting oxygen index(LOI) and the UL94 protocol were used to characterize the thermal stability and fire properties of composites. The results indicate that MAPK was successfully intercalated into the interlayer of LDHs and MAPK has a different arrangement in the interlayer of organicLDHs for different preparation methods of LDHs. PP/ionexchangeorganicLDHs (PP/ion-o-LDHs) and PP/roast reductionorganicLDHs (PP/ro-o-LDHs) show a better dispersion of LDH in PP than PP/co-precipitationorganicLDHs (PP/co-o-LDHs) composites. Compared to pristine PP, the peak heat release rate of PP/10% co-o-LDHs, PP/10% ion-o-LDHs and PP/10% ro-o-LDHs decreased by 21%, 33% and 30% respectively. The limiting oxygen index increased by 3.7 from 17.2(in PP) to 20.9(in PP/10% ion-o-LDHs). All of the composites could obtain an HB in the UL-94 horizontal burning. © (2013) Trans Tech Publications, Switzerland. Source

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