Papers by Author: Peng Sun

Abstract: The TiO₂-activated carbon fiber (ACF) was successfully prepared by electrospinning and thermal treatment. The nanofiber was characterized by scanning electron microscopy (SEM), thermogravimetric-differential thermal analysis (TG-DTA), X-ray diffraction (XRD) and Brunner-Emmett-Teller method (BET). The results showed that the average diameter of ACF was in the range 200-500 nm, and the preoxidation temperature and carbonation temperature were 250°C and 500°C, and the anatase TiO₂ appeared in fiber after carbonation, and TiO₂-ACF specific surface area was 1146.7 m²/g. The TiO₂-ACF was used for adsorption of low concentration SO₂. The results showed that the adsorption rate increased with an increase in SO₂ concentration, furthermore the adsorption rate increased with prolonged adsorption time, the high adsorption rate was 67.6% after 40 min. While temperature was below 60°C, the adsorption rate decreased as the temperature increased, however when temperature was above 60°C, there was a slight increase of adsorption rate as the temperature increased.

Abstract: The poly (vinyl pyrrolidone) (PVP)/Cobalt Acetate Composite nanofibers were prepared by electrospinning method. Then we got Co₃O₄-activated carbon fiber (ACF) from PVP/Cobalt Acetate composite nanofibers after preoxidation, carbonation and activation. Study the effect of different adsorption conditions on the adsorption rate of low concentration SO₂. The SEM, TG-DTA, XRD, FT-IR and BET analysis methods is used to characterize. The results show that the specific surface area of Co₃O₄-ACF obtained reach 1238.5 m²/g, and it contains Co₃O₄ after carbonation. The adsorption rate can reach 69.0%, when the concentration of SO₂ is 1.0 μg/mL, adsorption temperature is 20, and adsorption time is 10 minimum.

Abstract: Polyvinglpyrrolidone (PVP), cetyltrimethylammonium bromide (CTAB), and poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (P123) were used as templates, respectively. The morphology, structure and luminescent properties of the products were characterized and studied. The results show that all the products are pure LaPO4 with hexagonal structure. Comparing with the morphologies of LaPO4:Eu3+ nanocrystals prepared with PVP and CTAB as templates, the LaPO4:Eu3+ nanocrystals with P123 as template present regular spherical structure. The sizes of all products are in the range of 50–120 nm. When ultrasonic time was 2 h, the tendency, intensity and stability of fluorescent irradiation is obviously difference with different templates. In addition, the luminescent intensity of the LaPO4:Eu3+ nanocrystals using PVP as template is the strongest and using P123 as template is the weakest. All above results indicate that the template kinds have played an important role in the morphology and luminescent properties of the LaPO4:Eu3+ nanocrystals.

Abstract: In this paper, we made two different chemical conversion coatings on aluminum alloy by TiOSO4 and Na2WO4. The morphology of the chemical conversion surface layers were observed by scanning electron microscopy (SEM). The microcosmic phase structures were characterized using X-ray diffraction (XRD). Electrochemical method was used to study the coatings corrosion resistance. The results indicated that the two conversion coatings were crystal structure material, the surface of coating were both show pothole structure. TiOSO4 coating have better corrosion resistance than Na2WO4 coating.

Abstract: Ti-W composite coating was made by chemical conversion method on aluminum alloy. By orthogonal experiment, the optimal coating-forming conditions were the concentration ratio of TiOSO4 and Na2WO4 was 0.3 g/L:0.3 g/L、KMnO4 1.0 g/L、NaF 1.0 g/L、reaction temperature 40°C、reaction time 2min. The morphology of the coating was observed by scanning electron microscopy (SEM). Coating composition and the microcosmic phase structure were characterized using energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD) respectively. Electrochemical test was used to study the coatings corrosion resistance. The results indicated that the composite chemical conversion coating is a crystal structure material that composites with Al、Mn、W、Ti et al., its surface appears as a accumulation of fibroid spherical particles, the crystallinity of conversion coating is better than uncoated sample obviously. The corrosion potential of the coating is improved to -0.440V, they were both prove the corrosion resistance has improved.

Abstract: A chrome-free chemical conversion coating was prepared using stannous sulfate as the main salt. The morphology of the chemical conversion surface layer was observed by scanning electron microscopy (SEM). Coating composition and the microcosmic phase structure were characterized using energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD) respectively. Electrochemical method and dropping test were used to study the coatings corrosion resistance. The results indicated that the tin salts conversion coating is a crystal structure material that composites with Sn-F-O-Al et al., the surface appears as a accumulation of spherical particles, the crystallinity of conversion coating is better than uncoated sample obviously, the corrosion resistance has improved too.