Papers by Author: Feng Cao

Abstract: Poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/organoclay blends were prepared by solution blend method. The effect of organoclay on the thermal degradation and crystalline morphology properties were studied by thermogravimetry (TG)X-ray diffraction (XRD) and polarizing optical microscopy (POM) analyses. TG results indicates better processability of the blends with 5wt% organoclay than that of pure PHBV. XRD results show that the organoclay does not modify the crystal structure in the blends but only increase the intensity of diffraction peak. PHBV and PHBV/organoclay revealed integrated Maltese crossed spherulitic morphologies. While small-sized PHBV spherulites were formed when organoclay added to PHBV.

Abstract: Poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/CaCO₃ blends were prepared by solution blend method. The effect of CaCO₃ on the thermal and crystalline morphology properties was studied by differential scanning calorimetry (DSC), thermogravimetry (TG) and polarizing optical microscopy (POM) analyses. DSC showed the CaCO₃ affected the crystallization behavior of PHBV as heterogeneous nucleation agent. TG results indicated better processability of the blends with 3wt% CaCO₃ than that of pure PHBV. Integrated Maltese crossed spherulitic morphologies were revealed for both pure PHBV and PHBV/CaCO₃ blend. While small-sized PHBV spherulites were formed when CaCO₃ added to PHBV.

Abstract: Several blends of poly (trimethylene terephthalate) and the classical mesogen jacketed liquid crystal polymer poly{2,5-bis[(4-butoxyphenyl)oxycarbonyl]-styrenes}(PBPCS) have been prepared with different compositions. The rheological and crystallization properties of the prepared blends have been investigated. The effect of the PBPCS amount on the complex viscosity was quit prominent at low frequency, and decreased with increasing frequency. Differential scanning colorimetry(DSC) experiments showed that adding small content of PBPCS (0.5wt%), the melting point of was slightly higher than that of pure PTT and The crystallinity of PTT incresased.

Abstract: Poly(trimethylene terephthalate) (PTT), and three different rubbers(maleated styrene-butylene-co-ethylene-styrene copolymer (SEBS-g-MA), ethylene-propylene-diene copolymer grafted with maleic anhydride (EPDM-g-MA) and maleic anhydride grafted poly (ethylene-octene) (POE-g-MA)) were mixed in the melt state. Their rheological properties and spherulite morphology were investigated. Rheological properties shows torque decreases with the time increasing for all blends. PTT/SEBS-g-MA blend have better processability than PTT/EPDM-g-MA and PTT/ POE-g-MA blend. Polarizing optical microscopy (POM) experiments showed that the introduction of rubber chain greatly affects the size of the PTT spherulites. Small-sized PTT spherulites were formed when rubber added to PTT.

Abstract: The LaFeO3 nanoparticle was synthesized using Fe(NO3)3 and La(NO3)3 as starting materials by homogeneous precipitation method. The as-prepared LaFeO3 product was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). XRD and SEM demonstrate the successful synthesis of single phase perovskite LaFeO3 and with 60-80 nm particle size. It was found that the as-prepared LaFeO3 shows strong visible-light absorption with absorption onset of 532 nm, indicating a narrow optical band gap of 2.33 eV. Furthermore, the as-prepared LaFeO3 shows high visible-light photocatalytic activity for decomposition of methylene blue in comparison with the commercial Degussa P25.

Abstract: To prolong blast furnace campaign life, a great deal of research work has been carried out on the structure of stave cooler in the past decades, which, in turn, produced favorable results. However, due to the different thermal expanding property of the metal stave from that of the brick lining, the latter is subjected to crack, slide and damage. To solve the problem, a new stave cooler has been developed in this paper. Thus, a certain amount of anchors were welded on the traditional stave cooler, the unshaped gunning material can be fixed by anchors and the whole-lining be formed by gunning. The results of thermal simulating indicates: the bonding strength between the surface of stave cooler with anchors and the gunning lining is much higher than that between the surface of traditional stave cooler and the brick lining. Consequently, the service life of blast furnace will be extended. The optimizing design of the anchor was also described in the paper.

Abstract: A double-sheets model was proposed to investigate the interlayer structure and properties of hydrotalcite (HT) containing CO₃^2-, CrO₄^2-, SO₄^2- and NO₃^- using density functional theory, and the configuration and distribution of four anions in the interlayer of HT were obtained. The frontier orbital of the host layer interacts with that of the guest anions, and the electron transfers from HOMO of anions to LUMO of the host layer. Moreover, the order in the absolute value of binding energy is: CO₃^2- >CrO₄^2- >SO₄^2- > NO₃^-, that remains consistent with the ion-exchange ability of HT reported.

Abstract: The LaNiO₃ nanoparticles were prepared by a sol-gel process. The LaNiO₃ nanoparticles were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-Vis diffuse reflectance spectroscopy (DRS). XRD and SEM demonstrate the successful synthesis of single phase perovskite LaNiO3 and an average grain size of 80 nm in diameter. It was found that the as-prepared LaNiO₃ shows strong visible-light absorption with absorption onset of 545 nm, indicating a narrow optical band gap of 2.28 eV. Consequently, LaNiO₃ nanoparticles show high visible-light photocatalytic activity for decomposition of methyl orange in comparison with the commercial Degussa P25. The photocatalytic experiment shows the high photocatalytic activity for the decomposition of methyl orange under visible-light irradiation, which is attributed to the strong visible-light absorption.

Abstract: With China cast CAE / InteCAST, we analyzed the ordinary valve casting parameters of solidification process, flow and heat transfer, and frequency smelting refining furnace used in the process of feeding wire, argon technology in the intermediate. Comparison-ray testing and physical anatomy of the results, we developed nuclear power valve steel casting process parameters. The results showed that the software forecast casting the shrinkage tendency of value; frequency smelting refining controlled sulfur, phosphorus and aluminum content; products fully comply with the ASTM A216/A216M overcome hot cracking defects, improving the casting ability of anti-fatigue.

Abstract: The two-sheets model was proposed to investigate interlayer structure and properties of Mg/Al layered double hydroxides (LDHs) containing F^-, Cl^-, Br^-, I^- and OH^- using density functional theory (DFT). The results show that four types of halogen anions in the interlayer of LDHs have the same configurations due to simple sphere structures of isolated anions. As the size of halide anions increasing, the interlayer spacing d_c increase. Mulliken charge analysis illustrates that the host layers interact with the guest anions by the electrostatic interaction and hydrogen bonding, and the charge transfers from anions to layers. The frontier orbital of the host layer interacts with that of the guest anions, and the electron transfers from HOMO of anions to LUMO of the host layer. Moreover, the order in the absolute value of binding energy is: OH^- >F^- >Cl^- >Br^- >I^-, that remains consistent with ion-exchange ability of LDHs reported.