Papers by Author: Bing Bing Fan

Abstract: Using the density functional theory method, we have characterized the geometrical structures and adsorption energy of water clusters adsorption on graphite surface. When one water molecule inter- acts with graphite surface, one of the H-O bonds formed hydrogen-bond with carbon atom in graphite sheet; in the two water molecules structure, the linear dimmer nearly parallel to the graphite surface, and also formed the hydrogen-bond; when the number of water molecules increased to six, all the H-O bond that point to the graphite surface has formed Hydrogen-bond with it. The binding energy of the water clusters with a graphite surface depends only on the number of water molecules that form hydrogen bond.

Abstract: High-temperature anti-oxidation coating was prepared by a milling process, which mainly composed of flake graphite and hexagonal BN (hBN). The coating was brushed on the sliding plate surface and dried in air for 24 h, The surface of the sliding plate painted was smooth and without peeling, suggesting a strong bonding strength. The samples were heated at 1200 °C for 20 min to evaluate the mass-loss rate. The mass-loss rate of the slide gate painted is 3.7%, less than the un-painted 5.1%. XRD and SEM techniques were used to characterize the as-heated samples. The results showed that the surface of the slide plate painted was skin rolling. And the graphite reacted with oxygen at an elevated temperature to reduce oxygen concentration. In addition, hBN also reacted with oxygen to form B2O3, which also has an oxygen-resistant role in the sliding plates. These coatings exhibited unique oxidation-resistant properties, and the service life of the coated sliding plates was obviously improved.

Abstract: SiO2-SiC composite particles were prepared using a sol-gel process. BaTiO3 powders were synthesize through solid-state reaction. They were mixed as microwave absorbents with Fe3O4 powders to obtain the complex absorption. Epoxide resin (EP) was used as matrix and solidified with the mixtures. The techniques of DSC-TG, XRD were used to characterize the composite particles and the obtained compacts. A vector network analyzer was used to measure the reflectivity of the SiO2-SiC-based composites. The effects of the aborbents’ contents on the reflection of the microwave absorption materials were disscussed. It was found that SiO2-SiC composites could be prepared using sol-gel process and BaTiO3 powders could be synthesize through solid-state reaction. The results indicated that SiO2-SiC composite is contribute to absorb microwave, where SiO2-SiC: BaTiO3: Fe3O4 = 6:2:2 (vol %), the frequency region in which the maximum reflectivity is more than -10 dB is 5.4-7.6 GHz.