• QI LIU

      Articles written in Bulletin of Materials Science

    • Study of structural transformations and phases formation upon calcination of Zn–Ni–Al hydrotalcite nanosheets

      Zhanshuang Li Yanchao Song Jun Wang Qi Liu Piaoping Yang Milin Zhang

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      In this paper, we describe a general process for the synthesis of highly crystalline Zn–Ni–Al hydrotalcitelike materials. The structure and thermal decomposition of the prepared samples are studied by XRD, FT–IR, TG–DSC, SEM, TEM and N2 adsorption/desorption. The morphology of large-sized, porous and hexagonal platelike Zn–Ni–Al hydrotalcite is affected by calcination temperature. BET specific surface area and pore volume are observed to increase with increase of the calcination temperature up to 700°C followed by a further decrease with increasing temperature.

    • Preparation of semi-IPN(BA–VAc–VAE) by emulsion polymerization and its properties investigation

      Shi Luo Zonghui Liu Bailing Liu Qi Liu

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      A semi-interpenetrating polymer network (semi-IPN) combining vinyl acetate–ethylene (VAE) and butyl acrylate (BA), as well as vinyl acetate (VAc), was prepared through emulsion polymerization with the help of self-made dispersant and diethylene glycol diacrylate (DEGDA), the cross-linking agent. Both the dispersant and DEGDA had significant contribution on the preparation of semi-IPN(BA–VAc–VAE). And, the DEGDA had a strong influence on the conversion of polymerization system. The effects of emulsifiers and their amounts on the stability of obtained emulsions have been determined, and the best choices have been made after series experiments. The optical microscopy (OM), FTIR and DSC methods were adopted to characterize the structure and composition, morphology, and Tg of the prepared emulsions, respectively. Various comparisons have been made between the semi-IPN and VAE emulsions, and the experimental results indicated that the semi-IPN(BA–VAc–VAE) had been developed with improved properties in both water resistance and adhesion.

    • Ex situ synthesis of G/$\alpha$-Fe$_2$O$_3$ nanocomposite and its catalytic effect on the thermal decomposition of ammonium perchlorate

      MERIEM AMINA FERTASSI QI LIU RUNZE LI PINGAN LIU JINGYUAN LIU RONG-RONG CHEN LIANHE LIU JUN WANG

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      $\alpha$-Fe$_2$O$_3$ nanoparticles were prepared by a facile hydrothermal method using ferric chloride hexahydrate(FeCl$_3$·6H$_2$O) as a precursor. Graphene oxide (GO) was synthesized using a modified Hummers method and graphenenanosheets (G) were successfully obtained by thermal reduction of GO. G/$\alpha$-Fe$_2$O$_3$ nanocomposite was prepared using ex situ synthesis in the presence of $\alpha$-Fe$_2$O$_3$ nanoparticles and GO solution. The characterization of the as-prepared materialswas performed using X-ray diffraction analyses and Fourier transform infrared spectroscopy; their morphology wasinvestigated by scanning electron microscopy and transmission electron microscopy; the specific surface area (SBET) wasdetermined by nitrogen adsorption; their catalytic activity on the thermal decomposition of ammonium perchlorate (AP) wasinvestigated by differential thermal analysis (DTA). The results of DTA indicated that the obtained nanomaterials contributein ameliorating the thermal decomposition of AP; specifically, the high decomposition temperature of AP decreases from432 to 380$^{\circ}$C. A significant decrease in the activation energy was also achieved in the presence of these nanomaterials, and the mixture of ammonium perchlorate with G/$\alpha$-Fe$_2$O$_3$ showed the lowest value (from 129 to 80.33 kJ mol$^{−1}$).

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