Papers by Author: Gao Yang Zhao

Abstract: A superplasticizer (WPS) was synthesized from waste plexiglas and sodium allysulfonate in this paper. Poly (methyl methacrylate-co-ethyl acrylate) grafling sodium allysulfonate (PMMA-g-AS) was prepared through reactive extrusion in self-single screw extruder and hydrolysis reaction. The structures of the WPS was characterized by FT-IR spectrometer. The results show that structure of the WPS are clear. By using UV-visible adsorption spectrophotometer, micro-electrophoresis potential analyzer, and X-ray photo spectroscopy, the adsorption characteristics and surface electrochemical properties of WPS were studied in comparison with traditional naphthalene sulfonated formaldehyde condensates (FDN) whose dispersion ability mainly depends on electrostatic repulsive forces. The results indicated that the adsorption behavior of WPS on gypsum particles follows a Langmuir isothermal adsorption model with an adsorption heat of 18.79 kJ/mol and an adsorption layer thickness of 17. 52 nm. Adsorption isotherm suggested that Langmiur single layer adsorption occurred during the process of adsorption of WPS and FDN on gypsum particles.

Abstract: In this paper, superplasticizer was synthesized from waste plexiglas and sodium allysulfonate (WPS). Poly(methyl methacrylate-co-ethyl acrylate) grafling sodium allysulfonate (PMMA-g-AS) was prepared through reactive extrusion in self-single screw extruder and hydrolysis reaction. The structures of the WPS were characterized by FT-IR spectrometer. The results show that structures of the WPS are clear. Properties of WPS and traditional naphthalene sulfonated formaldehyde condensates (FDN) were investigated, when water-cement ratio (W/C = 0.29) and the dosage of superplasticizer is 0.6 wt.% of cement, water reducing rate of mortar is 22.1%, which is 7.3% higher than that of FDN. BWP of the mortar of WPS is 1.4%. In addition, the compressive strengths of mortar of 3 d, 7 d and 28 d are higher than that of FDN, respectively, indicating that over-all performance of WPS reaches the standard of superplasticizer and its ratio of performance to cost is higher than FDN.

Abstract: In this study, by using UV-visible adsorption spectrophotometer, ζ-potential analyzer and X-ray photo spectroscopy, the adsorption characteristics and surface electrochemical properties of WPS were studied in comparison with traditional naphthalene sulfonated formaldehyde condensates (FDN) whose dispersion ability mainly depends on electrostatic repulsive forces. WPS was prepared through free radical copolymerization in self-Single screw reactive extruder and synthesized from waste plexiglas and vinyl monomers by way of special extrusion modification. The results show that the adsorption of WPS and FDN on cement particle surface approximately conforms to Langmuir’s adsorption isotherm. The adsorption of WPS belongs to physical adsorption and its saturated adsorbed quantity was 5.38mg/g. When the dosage of WPS was 1 wt.% of cement, the thickness of the adsorption layer on the surface of cement particles was 61.2 nm. The ζ-potential of cement particle with WPS changed from positive (15 mV) to negative (-64.74mV) with its concentration increasing from 0 to 20 g/L and decreased from -65.19 to-39.82 mV (reducing by 38.9%) with its concentration of 10 g/L within 60 h.

Abstract: Amorphous SiO2 thin films were fabricated at different temperatures using sol-gel technique. The unipolar resistive switching behavior was observed in Cu/ SiO2/ ATO (SnO2: Sb) sandwiched structure when the SiO2 thin film annealed at 500°C. The average ratio of Roff /Ron is 102. We investigated the successful device using HRTEM and XPS. It shows that the Cu defuses into the SiO2 thin film and it forms CuSiO3 in the interface between SiO2 and ATO films according to the high resolution images.

Abstract: Using La(NO3)3•nH2O and Ni(CH3COO)2•4H2O as starting materials, alcohol mixed with methoxyethanol as solvent, the LaNiO3 (LNO) solution was prepared. Using this solution, conducting LNO films with sheet resistance of 10Ω were obtained. XRD and HRTEM indicate that the LNO films are epitaxially grown on LaAlO3 (LAO) substrates. Using Pb(CH3COO)2•3H2O, La(NO3)3•nH2O, Ti(OC4H9)4, Zr(OC4H9)4 as starting materials, the PZT films were prepared on the LNO films. The PZT films are c-oriented. The as-prepared PZT film has a remanent polarization of 34.7µC/cm2, superior to the PZT film with random orientation and a remanent polarization of 18.4µC/cm2 prepared on ITO/quartz substrate.

Abstract: SnO2:F transparent conductive thin films with the area of 500×500mm2 were deposited on glass substrates by spray pyrolysis using SnCl4•5H2O and HF as the starting material and dopant respectively in methanol. The effects of HF concentration on the crystallized status, microstructures, transmittance, conductivity and low emissivity performances of the films have been studied. The results indicated that when HF content was excessive the solution presented strong acidity and it was difficult to obtain the uniform and dense films. However, when HF content was less, the conductivity of the film was poor. In this paper, The optimal mount of dopant HF was investigated and the molar ratio of Sn to F is 1:0.5. And also the uniform and dense SnO2:F transparent conductive oxide thin films can be obtained, whose resistivity reached 6.36×10-4Ω•cm, and the average transmittance in visible region was 80%.The low emissivity of this film was 0.25, which could be used as the Low-E glass.

Abstract: In this paper, fluorine & antimony-doped tin oxide (FATO) transparent conductive thin films are deposited by Spray Pyrolysis on glass substrate, and low emissivity properties achieved. The emissivity of glass in far infrared region is optimized by changing the spray volume, the resistivity and sheet resistance of thin films. Research shows that the resistivity of thin films has important influence on infrared reflectance and hemispheric emissivity. This paper further investigates the quantitative relationship between emissivity and resistivity of low-E glass and also provides a basis for emissivity control and performance evaluation of Low-E glass.

Abstract: precursor solution was prepared using barium trifluoroacetae (Ba-TFA) and non-fluorine yttrium (Y) and copper (Cu) organic salts. The precursor solution was modified by benzalacetone (BzAcH), in which the Cu2+ were chelated with BzAcH, which preventing the loss of Cu in the pyrolysis process. Dense YBCO superconducting films with smooth surface, which confirmed by scanning electron microscopy (SEM), were repeatedly obtained through sol-gel process. X-ray diffraction (XRD) 2θ scanning and φ scanning indicated that the as-prepared YBCO films had good c-axis texture. YBCO films with superconducting transition temperature (TC) above 89K were obtained.

Abstract: with yttrium, barium, copper acetates as starting materials, a low-fluorine-content solution was prepared. YBa2Cu3O7-x (YBCO) films on LaAlO3 (LAO) single crystal substrates were fabricated by a new TFA-MOD method. Solution-derived YBCO films exhibited epitaxial growth, which was confirmed by X-ray diffraction (XRD). The humidity of the furnace atmosphere during annealing process influences the texture of YBCO film. Under high-humidity of furnace atmosphere, a-oriented grains, which were confirmed by scanning electron microscopy (SEM), were generated on film surface. High-resolution transmission electron microscopy (HRTEM), however, indicated that although a-axis oriented grains formed on the film surface, c-axis oriented grains occupied the area near the YBCO/LAO interface. High-performance YBCO films with Tc above 90K, and Jc more than 106A/cm2 at 77 K and zero magnetic field were obtained.