Papers by Author: Xin Wang

Abstract: Sn is one of the most important elements for the Cl2-evolving anode coatings, but it always used as a minor additive. In this paper, an Sn-based ternary oxide coating with its composition of SnO2-23wt%TiO2-21wt%RuO2 was prepared by a sol-gel technique through etching, painting, sintering and annealing. The differential thermal analysis (DTA) shows that the crystallization behavior of the ternary xerogel is more similar to that of pure xerogels SnO2. X-rays diffraction (XRD) indicates that the coating is composed of rutile phase (Sn,Ti,Ru)O2. Any other undesired phases, for example, anatase TiO2 and metallic ruthenium phases are not found in the coatings. The microstructure and the morphologies were studied by a transmission electron microscope (TEM) and a scanning electron microscope (SEM). The results of energy dispersive spectrometer (EDS) indicate Sn content in the coatings remain at high level and coincident with the nominal composition. The grain sizes in the coatings are around 4 nm. The voltage of Cl2-evolution and O2-evolution shows the ternary coating has good electrochemical properties.

Abstract: The crude magnesium is produced mainly by Pidgeon Process in China. Although Pidgeon Process has achieved certain technological advance in the past ten years, it is mainly by sacrificing energy, environment, and cheap labor. In the 21st century, human activities should be energy-saving and environment friendly. The equipment used in the Pidgeon process should be improved as early as possible by elevating its automatic level in order to save energy, protect the environment and realize scale economy of magnesium production. This will be the developmental trend of Pidgeon process in smelting magnesium.

Abstract: Of many polymeric biomaterials, hydrogels are of special importance because of their favorable biocompatibility and pertinence in delivering delicate bioactive agents such as proteins. Physical hydrogels have attracted much attention for controlled drug delivery because of the mild and aqueous conditions involved in trapping bioactive agents. This paper reviews our recent progress on developing a new class of physical hydrogels based on the supramolecular self-assembly between cyclodextrins and bioabsorbable poly(ethylene oxide) (PEO) or its copolymers. Being thixotropic, the hydrogels can be injected through needles and applied as injectable drug delivery systems. The properties of the hydrogels also can be fine-tuned with triblock copolymers where PEO segments flank hydrophobic or biodegradable segments in the middle.