Search

The thermal decomposition characteristics of microwave liquefied rape straw residues with respect to liquefaction condition and pyrolysis conversion were investigated using a thermogravimetric (TG) analyzer at the heating rates of 5, 20, 50 °C min−1. The hemicellulose decomposition peak was absent at the derivative thermogravimetric analysis (DTG) curve of liquefied residues, because it had been decomposed during the liquefaction. Furthermore, among the liquefied residues, the one from the reaction condition of 180 °C/15 min had the highest thermal stability under a high temperature (>700 °C). The DTG profiles revealed that raising the temperature heating rate could result in an increase in the maximum decomposition temperature. The apparent activation energy (Eα) values of the liquefied residues were lower than that of non-liquefied raw rape straw, whereas the recondensation reaction occurred at 180 °C/15 min remarkably increased the Eα. A noticeable increase in the Eα was observed for the liquefied residue from the 180 °C/10 min samples as the pyrolysis conversion increased from 0.15 to 0.55, suggesting a complex decomposition process with the increasing pyrolysis temperature. The liquefaction process could decrease the thermal decomposition temperature of biomass, which means higher reactivity and lower operational costs during pyrolysis. [ABSTRACT FROM AUTHOR]

FeO/CNTs nanocomposites, which were prepared by polyol-medium in situ high-temperature decomposition of Fe( acac) using PVP as stabilizing agent and modified with SDS, were further decorated with high-quality ZnS nanocrystal via a wet technique in glycol solution. The obtained ZnS/FeO/CNTs nanohybrids were characterized by XRD, FT-IR, Raman microscope, TEM, EDS, XPS, VSM and fluorophotometers. Results indicated that magnetic FeO nanoparticles and fluorescent ZnS nanocrystal were uniformly dispersed on the surface of CNTs layer-by-layer with PVP and SDS as stabilizing agent and ion-capture agent, respectively. The novel multi-functional nanohybrids exhibit super-paramagnetic properties with a saturation magnetization about 6·795 emu g at room temperature and show a strong emission band at 367 nm with a broad shoulder around 342-483 nm due to the interactions and/or background emissions of FeO and CNTs. The superparamagnetic and fluorescent properties of obtained products are promising for potential applications in magnetically guided and fluorescence tracing drug delivery systems. [ABSTRACT FROM AUTHOR]