Papers by Author: Bo Feng

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Authors: Bo Feng, Ji Yong Chen, Xing Dong Zhang
Authors: C. Huang, Shao Xing Qu, Bo Feng, R. Shen, Z.M. Hong, M.H. Li, Y.R. Liu, Xiao Hong Li, Jie Weng
Abstract: The purpose of this paper was to investigate the effect of various Chinese medicine adding methods on their contents in calcium phosphate (CaP) and the crystal structure of the CaP comparatively. In the present study, CaP was synthesized by the wet chemistry method, in which starting reagent grades calcium nitrate and diammonium phosphate were used as the molar ratio Ca/P=1.5. Chinese medicine parenteral solution, Salvia Miltirrhiza Bunge (SMB), was added into the Ca2+ and PO43- reactive solutions before, during or after synthesis process. CaP was synthesized without adding SMB as the control. UV-VIS spectrophotometer was used to measure the supernatant absorbency. Zeta potential was used to characterize the various CaP slurries. Thermogravimetry, X-ray diffraction and transmission electron microscope were used to characterize the various powders, respectively. The presented results showed that adding SMB during the reaction can obtain the maximal medicine content among the four different adding methods. There was a slight effect on the crystal structure of CaP by adding SMB.
Authors: C.G. Hu, W.L. Wang, Bo Feng
Abstract: The carboxyl modified carbon nanotubes were obtained by treating them in the concentrated nitric acid with a little surfactant. The complete electrochemical combustion of phenol has been found under 5 M at the carboxyl modified carbon nanotube electrode in phosphate buffer solution. The reaction was discussed in details. Due to the porous tubule of the structure of the carbon nanotube and large quantity of hydroxyl exists in the carboxyl modified carbon nanotube electrode, which were necessary for the continually electrochemical combustion of phenol. Long time potentiostatic oxidation showed that the phenol could be eliminated from the aqueous media without any foul at the carbon nanotube electrode.
Authors: Bo Feng, Jie Weng, Shao Xing Qu, Xing Dong Zhang
Abstract: A microporous apatite coating was fabricated by a heat-oxidation and chemical routine. The morphology, composition and structure were characterized by scanning electron microscopy with X-ray energy dispersion spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The components of the coating were predominantly apatite, next tri-calcium phosphate and octa-calcium phosphate. The pore size ranged from 1µm to5µm. The thickness of the coating was about 6µm ~ 10µm. The microporous coating was Ca-deficient carbonate apatite.
Authors: Bo Feng, Jie Weng, Yu Liang, Shu Xin Qu, Jin Wang, Xiong Lu
Abstract: A network-like porous layer on titanium was prepared by acid-etching with a mixture of CaCl2 and HCl. The pores ranged from 1 to 10!m. The small pores distributed in big pores. In the simulated biological environment, porous octacalcium phosphate (OCP) coatings spontaneously formed on the porous- surfaced titanium. Pre-calcification after acid-etching accelerated OCP precipitation. The OCP coatings had big pores of about 25!m and small pores of 1~3!m, the latter distributed in the former at different depth.
Authors: Bo Feng, Jie Weng, Jian Hui Zhao, L. He, S. Qi, X. Zhang
Authors: N. Wu, Jie Weng, Shu Xin Qu, Jian Xin Wang, Xiong Lu, Bo Feng
Abstract: In this work, triethyl phosphate (TEP) was used to bioactivating titanium. Titanium plates grafted with TEP were immersed in a two times concentrated simulated body fluid (2SBF) to investigate deposition of hydoxyapatite (HA) on the surface. A phosphate buffer solution (PBS) with bovine serum albumin (BSA) was used to evaluate adsorption of protein on the grafted titanium surface. The morphology, component and structure of samples were examined by scanning electronic microscopy, attenuated total reflection Fourier transform infrared spectroscopy and X-ray diffraction respectively. The concentration change of BSA in adsorption test was examined with the ultraviolet-visible absorption spectra (UV). The analyses showed that TEP grafted onto the titanium surface. In 2SBF, calcium and phosphate ions deposited spontaneously onto the grafted titanium surface and formed a HA coating with a network-like microporous structure after being immersed for 3 days. The coating consisted of HA particles with 180-265nm in thickness and 72-85nm in width. The diameter of the micropores was about 200nm. The HA coating appeared better uniformity than that on the modified titanium using phosphoric acid. BSA rapidly adsorbed onto the grafted titanium surface at first half an hour and then the adsorption quantity almost kept constant. These results indicate that TEP grafting is an effective approach to modify bioactivity of titanium.
Authors: H.Q. Rao, Jian Xin Wang, X. Lu, Bo Feng, Jie Weng
Abstract: In the present work, technique of plasma polymerization was used to generate amido (- NH2) and carboxyl (-COOH) on titanium surface for immobilizing bovine serum albumin (BSA). After plasma polymerization of allylamine and crylic acid, the contact angle with respect to double distilled water significantly increased. Surface components were detected by X-ray photoelectron spectroscopy and Fourier transform infrared reflection-absorption spectroscopy. The results showed that BSA was successfully immobilized on the titanium surface and the amounts of BSA on specimens were relied on the properties of thin film deposited through plasma polymerization, which was corresponding to the ultraviolet spectrophotometer result.
Authors: Lie Feng Liang, Jie Weng, Bo Feng, Shao Xing Qu
Abstract: Porous blocks of bioactive ceramics are a more preferable tissue substitute to replace and reconstruct the defected tissues in that their interconnective pores are beneficial to new tissue ingrowth. The most important specification requires the controlled interconnective pores with required mechanical strength. A novel chitin-gel-cast approach is utilized to prepare porous bioceramic blocks. In order to improve their interconnection of pores, several acids are selected to etch the windows between porous. Light microscope (LM) and Scanning electronic microscope (SEM) are used to investigate the etching effect on the windows and walls of porous blocks. The results show that the acid etching can improve the interconnection of porous blocks with slight decrease of compressive strength under carefully controlled process conditions.
Authors: Bo Feng, Jie Weng, Shao Xing Qu, Yong Xiang Leng, Zhong Rong Zhou
Abstract: Influence of heat-treatment conditions on wear resistance of titanium was investigated. Titanium plates were subjected to heat-treatment in air and water vapor respectively. Heat-treatments increased micro-hardness of titanium. The plate heat-treated in air (H) has the highest roughness and the plate treated in water vapor (W) lowest. After heat-treatment surface oxide was rutile. The friction coefficient of W was the lowest and almost stable at about 0.18. Non-heat--treated titanium plate (S) had a highest coefficient up to 1.1. Wear resistance of heat--treated titanium, especially W was significantly superior to non-treated titanium. The wear of S resulted mainly from adhesion failure, H involved with abrasive wear and fatigue failure. For W, a complex wear mechanism was probably existed.
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