Papers by Author: Jian Hong Liu

Abstract: In this paper two different thermal storage material were respectively covered by polymer layer, inorganic layer and simple way to join the concrete. Thermal energy storage and mechanical performance were researched, the reliable use methods of the thermal energy storage in the actual engineer were proposed.

Abstract: LiFePO4/PPy composites with different content of polypyrrole (PPy) were prepared by chemical oxidation reactions. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize the LiFePO4/PPy composite. The results showed that doped PPy did not destroy the olivine structure of LiFePO4 but decreased the intensity of the diffraction peaks, and PPy was found on the surface of LiFePO4 particles. PPy could remarkably increase the conductivity of the composite and improve the electrochemical performance of LiFePO4. The sample with 2.5 % (wt). PPy possessed a high initial discharge capacity of 144.5mAh/g at 0.1C. The results of both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) proved good cycle performances of the samples doped by PPy.

Abstract: AgCl@polypyrrole(PPy) nanocomposites were synthesized through in situ chemical oxidation polymerization by using poly(vinylpyrrolidane) (PVP) as dispersant, and some Au colloid were prepared by using KBH4 as reductant and sodium citrate as stabilizer, then the Au nanoparticles-AgCl@PPy hybrid material was formed by physical chemical reaction. Fourier transform infrared spectrometer (FTIR) and electron dispersive spectrometer (EDS) data suggested that the hybrid material were composed of Au, AgCl and PPy. An amperometric glucose biosensor was fabricated by adsorbing glucose oxidase (GOx) to an Au nanoparticles-AgCl@PPy hybrid material modified platinum electrode. The biosensor exhibited a super highly sensitive response to H2O2.

Abstract: A series of lithium iron phosphate /polypyrrole (LiFePO4/PPy) composite powders were synthesized by chemical oxidation method with different doping agent and oxidation agent. The composite powders were characterized by scanning electron microscopy (SEM), Fourier Transform Infrared Spectrum (FTIR), and X-ray diffraction (XRD). The results showed that the composite powders composed of PPy and LiFePO4. And the doping of polypyrrole in LiFePO4 could weaken the XRD intensity of LiFePO4 , but could not destroy its crystallization. With the increase of pyrrole in LiFePO4/ PPy composite powders, the polypyrrole on the surface of LiFePO4 increased and dispersed more homogeneously. Thermogravimetric analysis (TGA) data indicated the heat-stability of LiFePO4/PPy was very good that the composite powders would not oxidate till 300°C in the air flow.

Abstract: Ag/polypyrrole(PPy) composite nanoparticles within 100 to 150nm diameter were successfully synthesized. Fourier transform infrared spectroscopy(FTIR) and X-ray diffraction patterns(XRD) data suggested that the nanoparticles were composed of Ag and PPy. An amperometric glucose biosensor was fabricated by adsorbing of glucose oxidase(GOx) to an Ag/PPy nanoparticle-ethyl cellulose composite material modified platinum electrode. The biosensor exhibited a super highly sensitive response to the analyte with a detection limit of 1.0×10-7mol/L. Moreover, the biosensor showed quick current response. The effects of some factors, such as working voltage, pH value , mensuration temperature and mass ratio of Ag/PPy nanoparticles to ethyl cellulose, were also studied.

Abstract: Nanosized barium ferrite spinel particles were prepared with the aid of ultrasound radiation by a precursor approach. A precursor was got by sonicating an aqueous solution of BaCl2, Fe (NO3)3·9H2O and urea firstly. Nanosized BaFe2O4 particles with a size of ca.40nm were prepared after the precursor was heated at 950 °C for 15 h. The nanosized barium ferrite particles and the precursor were characterized by powder X-ray diffraction, scanning electron microscopy, FT-IR and differential scanning calorimetry.

Abstract: Copper ferrite powders were successfully synthesized by sonochemical method. The resultant powders were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), FT-IR, differential thermal analysis-thermal gravimetric (DTA-TG), differential scanning calorimetry (DSC) and VSM. The particle saturation magnetization (Ms) is 66 emu/g and an intrinsic coercive force (iHc) is 2100 Oe when the precursor calcined at 950 °C for 15 h.

Abstract: WO3 sol was prepared through the sol-gel process. Ethanol, acetone and SiO2 sol were added to the WO3 sol. The WO3 thin films on glass substrate were obtained with the hybrid sol by the dip-coating technique, and then were heat-treated at different temperatures for a certain time. X-ray diffractometer and scanning electron microscope were used to characterize the crystal structure and surface morphology of these coatings. Visible light transmittance changes of the thin films irradiated under UV light were measured with UV spectrometer. The experimental results demonstrated that photochromic effect, hardness and uniformity of thin films were improved when the thin films are obtained with the hybrid sol.

Abstract: TiO2 coatings on ceramic substrate were prepared using TiOSO4 and silica sol. Coatings were then heat-treated respectively at 300°C, 400°C or 500°C for 30mins. Degradation of the solution of chlorinated methane by UV light and TiO2 coating were investigated. It can be concluded from the results that the coating with composition of 80wt%TiO2-20wt%SiO2 heated at 500°C display better degradation effect than the other coatings. As the initial concentration of chloromethane goes up, the degradation rate increases; while as the degree of substitution by chlorine goes up, the catalytic effects decreases.

Abstract: Sol-gel coatings of mixed TiO2-SiO2 had been deposited on ceramic substrates by spraycoating technique to study their hydrophilic and photocatalytic behavior on exposure to sunlight or ultraviolet illumination. The range of the films heat-treatment temperature is from 300°C to 500°C. AFM and XRD analysis were used to characterize the crystal structure and surface morphology of these coatings. Hydrophilic property was evaluated by water contact angle measurement under sunlight illumination condition, and photocatalytic activity by decomposition rate of aniline blue under ultraviolet illumination. Attrition resistance experiment was also carried out to test the hardness and adherence strength of these films. The experimental results demonstrate that this coating possesses high photo-activity and excellent adhesion to ceramic substrates.