No abstract

The thermal characteristics of Paulownia sawdust (PS), bamboo sawdust (BS), rice lemma (RL), and corncob (CC) in an oxidizing atmosphere were investigated using thermogravimetric analysis. The results indicated that the reaction of biomass oxidative decomposition took place in two main phases: devolatilization and char oxidation. Among various types of biomass, BS was found to possess the highest oxidative decomposition reactivity followed by PS, CC, and RL. Additionally, an increase in heating rate led to a significant improvement of the reactivity. The kinetic modeling of the oxidation reaction with the direct fitting method using the DRPM model showed a satisfied match with the experimental data, and the activation energy of biomass during the devolatilization process was higher than that of the char oxidation process. The activation energy of devolatilization was in the range of 80.7 to 133.8 kJ/mol, while that value of char oxidation fluctuated between 41.7 and 67.5 kJ/mol. In addition, with an increase in the heating rate, a marked compensation effect between the activation energy and pre-exponential factors was observed.

Compounds containing [B10H10]2− cluster are promising candidates that can be used as high energetic fuels and burning rate modifiers for propellants. The ignition and combustion behaviors of [N(C2H5)4]2B10H10 were investigated using a laser ignition system in air. Results show that [N(C2H5)4]2B10H10 (∼2.0 mm) is ignited with a delay of around 350 ms and threshold ignition energy of 0.7 J at laser ignition power density of 1.14×107 W/m2. Furthermore, the combustion of [N(C2H5)4]2B10H10 in air is found to undergo three stages of decomposition, incomplete combustion of the volatile pyrolytic products, and ejection and combustion of the molten dehydrogenated framework, giving massive smoke and a characteristic pyrotechnic flame.

No abstract

A novel hierarchical Fe 3 O 4 /TiO 2 hollow microspheres were prepared by combining sol-gel process, hydrothermal etching technology, and high-temperature calcination. The microspheres displayed excellent performance in the photodegradation of methylene blue under visible light. The Fe 3 O 4 /TiO 2-LiNO 3 composite phase change material showed high latent heat of fusion without leakage of salts. The morphology and properties of the Fe 3 O 4 /TiO 2 hollow microspheres and the Fe 3 O 4 /TiO 2-LiNO 3 composite phase change material were investigated by field emission scanning electron microscopy (FESEM), Ultraviolet-visible (UV-Vis) spectroscopy and differential scanning calorimetry (DSC). The results show that the hierarchical Fe 3 O 4 /TiO 2 hollow microspheres have potential applications in energy materials.