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Multi-walled carbon nanotubes (MWNTs) were separately modified using chitosan (CS) through covalent grafting (MWNTs-CS) and non-covalent blending (MWNTs/CS). The modified MWNTs were characterized by FTIR, SEM, XRD, thermogravimetric analysis (TGA), and UV-vis spectroscopy. Then, they were incorporated into starch to compare their effects on the structure and properties of the resulting nano-composite films. The results showed that CS and MWNTs were homogeneously mixed in MWNTs-CS, while they were self-aggregated in MWNTs/CS. Moreover, MWNTs-CS presented a better dispersion property in aqueous solution and in starch matrix, compared with MWNTs/CS. Loading of MWNTs-CS into starch not only improved the tensile strength and Young's modulus of the composite films, but also simultaneously increased the elongation at break. However, addition of MWNTs/CS just made the composite films more brittle. Furthermore, the migration rate of MWNTs-CS from films to aqueous solution was lower than that of MWNTs/CS when their composite films were immersed in water. The better performance of the composite films containing MWNTs-CS compared with those containing MWNTs/CS can be attributed to the enhanced dispersion of MWNTs-CS and improved interfacial adhesion with starch. Therefore, MWNTs-CS are regarded as promising nano-fillers to reinforce biopolymers and thus promote their applications in food packaging and biomedical areas. Starch/Stärke 2016, 68, 220-229 Comparison studies on covalently and non-covalently modified MWNTs. . .

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3D mesoporous Bi2WO6 flower-like spheres, which compose of nanosheets, were successfully synthesized by simple hydrothermal treatment. Bi2WO6 flower-like spheres exhibited high photocatalytic activity to tetracycline under visible light irradiation, because of the mesoporous structure, narrowed band gap and high surface area. Therefore, 3D mesoporous Bi2WO6 flower-like spheres can be a promising candidate material to be applied to the field of wastewater treatment.

Mesoporous Ni/La2O3/γ-Al2O3 catalysts with different La contents (0, 0.5, 1.5, 2.5, 3.5, and 4.5 wt.%) were prepared by the step-by-step impregnation method. The physicochemical properties of the prepared Ni/La2O3/γ-Al2O3 catalysts were characterized by H2-TPR, XRD, BET, O2-TPO, and TG. The effect of La dosage on the catalytic performance of Ni/γ-Al2O3 catalyst for dry reforming of methane was further investigated. The results show that the La content has a significant effect on the reducibility of high-valence Ni species, specific surface area, pore size, and pore volume as well as the catalytic performances. The high-valence Ni species in the NL3.5A catalyst precursor has high reducibility. And the specific surface area, pore size and pore volume of the NL3.5A catalyst are 145.9 m2 g−1, 11.7 nm, and 0.47 cm3 g−1, respectively. The catalytic activity of the series of prepared mesoporous Ni/La2O3/γ-Al2O3 catalysts follows the order: NL3.5A > NL2.5A > NL4.5A > NL1.5A > NL0.5A > NL0A. Namely, the NL3.5A catalyst possesses the best catalytic activity. The CH4 and CO2 conversions of NL3.5A catalyst are 61.6 and 39.1% at 600 °C, respectively. Additionally, it maintains a superior recycle capability for dry reforming of methane reaction because of the high coke resistance compared with the Ni/γ-Al2O3 catalyst.