Ren Ying; Wang Renjie; Cheng Qiaohuan; Chen Qianqian; Xu Zhigao
Abstract
Diamond-like carbon (DLC) coatings, due to excellent tribological and biological properties, were used wildly to improve the wear resistance and corrosion resistance of the metal-based artificial joints. In this work, DLC coatings were deposited by a vacuum arc using the anode-cathode diameter ratio ...
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Diamond-like carbon (DLC) coatings, due to excellent tribological and biological properties, were used wildly to improve the wear resistance and corrosion resistance of the metal-based artificial joints. In this work, DLC coatings were deposited by a vacuum arc using the anode-cathode diameter ratio of da/dc=3/1 with the negative bias applied to the P2000 steel substrate. The relation between the substrate bias and properties of DLC coatings was investigated. The study showed that DLC coating had lower ratio of sp < sup > 2 /sp < sup > 3 and lower friction coefficient at higher bias of – 750 V. With increasing bias, the wear particle size of DCL coatings tended to move towards the distribution of smaller particles. Comparing with the uncoated P2000, P2000 coated with DLC deposited at – 750 V had better biocompatibility. It was revealed that DLC coating deposited by a vacuum arc technique in conjunction with high substrate DC biasing can improve the tribological property and biocompatibility of P2000.

Wang Renjie; Ren Ying; Chen Qianqian; Cheng Qiaohuan; Wang Shun
Abstract
Functionalized polystyrene (PS) microspheres are promising materials for the isolation of the chiral drugs due to their properties, such as a large surface area, high chemical stability and tunable morphology. Considering 10-100 μm microspheres are suitable as the matrix materials of the chiral stationary ...
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Functionalized polystyrene (PS) microspheres are promising materials for the isolation of the chiral drugs due to their properties, such as a large surface area, high chemical stability and tunable morphology. Considering 10-100 μm microspheres are suitable as the matrix materials of the chiral stationary phase, and there are few reports on this. Here we report a facile synthesis of the tens-micron-sized carboxylated PS microspheres by a technology between the dispersion and suspension polymerization. The relation between the reaction solutions and the size of the carboxylated PS microspheres were investigated. The study showed that, the more H2O were used in the reaction solutions, which lead the principle of the reaction more close to the suspension polymerization, the larger size of the carboxylated PS microspheres. In addition, more acrylic acid would destroy the stability of the sphere morphology. Comparing the particle size distribution and morphology, it was revealed that tens-micron-sized carboxylated PS microspheres with narrow size distribution can be fabricated with the ratio of H2O/Ethanol 30/20 and the proportion of carboxyl groups reached to ~11%.
