Papers by Author: Ye Bin Cai

Abstract: Polypropylene grafted with maleic anhydride (PP-g-MA) was prepared and then was used as compatibilizer in the alloy of r-PET/PP to improve the compatibility of different phases. The influences of grafting ratio of MA, the additive amount of PP-g-MA, and the ratio of r-PET and PP to the flowability and the mechanical properties of r-PET/PP were researched. The results obtained show that PP-g-MA can improve the compatibility of different phases; the favorite grafting ratio of MA on PP mainchains is 1.4%; when the additive amount of PP-g-MA is 12%, melt index of r-PET/PP indicates that not only the flowability of r-PET/PP becomes better but also the tensile strengthen is higher; the ratio of r-PET and PP should be designed at 20/80 in order to obtain satisfied results.

Abstract: Friction and wear tests of Al₂O₃ and SiC were conducted from room temperature to 1200 °C both in air and in vacuum. Results show that the wear mechanism of Al₂O₃ is dominated by micro fracture, debris abrasive and delamination at temperatures below 600 °C, while is controlled by plastic deformation and recrystallization among 600~1200 °C, resulting in an obvious decrease of wear loss. The wear rate and surface microstructure of SiC are closely depending on the testing temperature, atmosphere and contact pressure. Oxidation of SiC at elevated temperatures plays important role on the wear rate. Self lubrication of both Al₂O₃ and SiC at high temperatures was observed, which is mainly depending on the formation of a specific surface layer composed of nano-particles or very thin glassy film.

Abstract: In this work, synthesis of the nanocrystalline Ce_0.8Nd_0.2O_1.9 Solid solution Powders by a nitrate-glycine gel-combustion process was investigated. The effects of glycine/metal ratio and calcination temperature on the powders phase structure, morphology and particle were investigated. TG-DSC curves and XRD peak of different glycine/metal ratio show that smaller particle size can be obtained with a slightly fuel-deficient ratio. XRD results indicate that the as-prepared powders are crystallinzed in a single fluorrite structure. The crystalline size ranges from 9 nm to 24 nm, which increases with the increase of calcination temperature. The SEM results imply some organic agent may be eliminated by high temperature calcination process.

Abstract: In a neutral environment, Chrysotile nanotubes have been synthesized by hydrothermal method, with MgO and SiO₂ powder as the starting materials. X-Ray Diffraction(XRD), Scanning Electron Microscopy(SEM), Transmission Electron Microscopy(TEM) are used to characterize the crystal structure and morphology of the as-prepared samples. We found that the diameter of Chrysotile is uniform. Their outer diameter is about 30~50 nm and the inner diameter is about 6~8 nm. The length of them is a few hundred nanometers. The XRD analysis indicates that the as-prepared Chrysotile is a Rhombohedral structures. The results of HRTEM and SAED showed that the {006} planes of serpentine roll up along the [600] direction to form the tubular structure. In addition, the curves of temperature and pressure with time showed that the water might participate in the reaction.

Abstract: Bismuth sulfide (Bi2S3) nanorods were successfully fabricated by sonochemical aqueous solution. The morphology, crystallinity and composition of samples at various growth stages were investigated by transmission electron microscopy (TEM), selected area electron diffraction (SAED) and X-ray diffraction (XRD). The results showed that the Bi2S3 nuclei had an obvious tendency to arrange themselves in rod-like arrays over extended length scales under soft template. Moreover the crystallinity would be reinforced with the elongation of the aging periods. The growth mode of particle−to−particle by self-assembly under soft template was proposed. The band gap energy of Bi2S3 nanorods was estimated at about 1.36 eV by UV-Vis absorption spectroscopy.