The graphene oxide (GO) was prepared by the Hummers method, and then modified with ethylenediamine to obtain aminated graphene oxide (NGO). The anti-corrosion and fire-proof waterborne epoxy composite coating was prepared by adding pentaerythritol phosphate (PEPA), aluminum triphosphate (ATP) and NGO to the waterborne epoxy resin, and then applied on the surface of steel sheet by air spraying method. The structure and morphology of GO and NGO were characterized by IR, XRD and SEM. The performance in anti-resistance and fire-proof resistance of the prepared coatings with different color ratios (pigment/resin ratio: P/B) was further investigated by means of electrochemical test, salt spray test, fire resistance test, residual carbon morphology analysis and thermogravimetric analysis. The results show that the composite coating with the P/B ratio of 0.2 presents the best comprehensive performance in anti-resistance and fire-proof.

Microcapsules of the urea resin encapsulated polysulfide sealant was designed and prepared successfully by in situ polymerization technology with the poly(urea-formaldehyde) resin (PUF) as shell material and the polysulfide sealant as core material. The surface morphology and chemical structure of the microcapsule were characterized by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR),respectively. In order to further investigate the effect of microencapsulation process on the mechanical properties of polysulfide sealant film after curing, a mixture of polysulfide sealant microcapsule and a certain proportion of vulcanizing agent was made, and then to apply polysulfide sealant containing film on standard nuts or to prepare test pieces of polysulfide containing sealant film respectively for mechanical testing. According to the relevant standards, the breaking torque, demolition torque, tensile strength and hardness of the polysulfide sealant film with unencapsulated and encapsulated polysulfide sealant respectively were comparatively tested. The results showed that based on the in-situ polymerization of PUF, the polysulfide sealant microcapsules with regular surface morphology, narrow particle size distribution, rough surface and dense shell were successfully prepared under the optimum reaction conditions. In comparison with the unencapsulated polysulfide sealant, the micro-encapsulated polysulfide sealant could greatly improve the mechanical properties of the sealant film. In short, the present research may provide an important reference for the exploring pre-coating technique of polysulfide sealant in the future.

During curing process, the temperature and strain of liquid epoxy resin, which was used for electronic packaging, were online monitored by fiber Bragg grating (FBG) sensors. The evolution of the temperature and strain with the curing time was measured by FBG sensors in the same mould for various desired spots, where locate at the same height but different positions. Besides, under the same experimental condition, the effect of the epoxy resin dosage on the temperature- and strain-evolution was also examined. The results show that during the curing process, the strain-time and the temperature-time curves for the epoxy resin at the same height but different positions have good consistency, which means that the temperature and strain responses during the curing process of the epoxy resin are independent of the horizontal position. In addition, for fixed embedded positions of FBG sensors, both of the maximum temperature during the curing process and the final residual strain after curing increase with the increasing dosage of epoxy resin.

The kinetics of precipitation and coarsening of Si-containing phases and the microstructure evolution of the die-casting plate of supersaturated Al-20%Si alloy during thermal treatment at 450 to 550℃ were investigated by means of differential scanning calorimeter (DSC), scanning electron microscope (SEM), and X-ray diffractometer (XRD). Results show that due to the pressure die casting induced rapid solidification and modification, the Al-20%Si alloy presented a non-equilibrium solidified and distorted microstructure with fine Si-phases (the average size of Si phase grains was less than 1 μm). In the annealing process the lattice distortion of the α-Al matrix was alleviated to some extent and the diffusion mechanism related with the coarsening of Si-phases seemed to be the bulk diffusion control (the coarsening index is approximately 3) with the activation energy of 69.59 kJ/mol. The annealing temperature exerted a significant effect on the coarsening rate constant but not on the coarsening index. In the initial stage of annealing, the tensile strength of the alloy decreased while the elongation increased with the increasing holding time. As the holding time longer than 90 minutes, the tensile strength and elongation both stabilized.

The effect of microstructure heterogeneity on the intergranular corrosion susceptibility of the extruded Al-alloy 6005A was investigated by means of optical microscopy (OM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and intergranular corrosion (IGC) test. Results show that the microstructure of the surface layer is quite different from that of the central portion of the Al-alloy profile. The surface layer is full of coarse grain bigger than 100 μm, coarse and scattered second phase particles and large angle (≥10°) grain boundaries, while the size of grains and second phase particles is much finer in the central portion, and many low angle grain boundaries can be observed this portion. The PCG (peripheral coarse grain) surface layer-reserved sample presents better IGC resistance than that of the PCG surface layer-removed sample, correspondingly the maximum depth of IGC was 37.08 μm for the former, while 459.28 μm for the later. The major cause why corrosion resistance of the surface layer LS superior to the central portion of the alloy may be ascribed to the less grain boundary and lower density of grain boundary precipitates of the surface layer.

Core-shell nanoparticles of Fe₃O₄/PAMAM/ZnO/TiO₂ and Fe₃O₄/PAMAM/TiO₂ were prepared by hydrothermal method with polyamidoamine (PAMAM) as template and isolation layer, while the construction mechanism and performance of which were investigated. The mophology, size, structure and proporties of these particles were characterized by HRTEM, EDS, XRD, SQUID and UV-Vis measurements. The results show that core-shell nanoparticles present clearly structure composed of magnetic core and shell, which were stacked with nanoparticles less than 5 nm in diameter, leading to high saturation magnetization and MB-adsorption rates. Althouth the interfacial contact area of core and shell was reduced by PAMAM isolation layer, trace electrons Fe²⁺ at the inerface could migrate into the TiO₂ shell through the residual interfacial contact area, and then combine with the holes in shell, which brought the narrowing of shell band gap and the red-shifting of the absorption spectrum and thus the decreasing of catalytic activity. As for Fe₃O₄/PAMAM/ZnO/TiO₂, the thicker PAMAM and ZnO layers cutted off the way of electrons migration to the TiO₂ shell. The heterogeneous structure of ZnO/TiO₂ facilitated the separation of the photogenerated electron hole pairs in shell. The new interface electronic states brought further red-shifting of the the absorption spectrum, higher utilization ratio of visible light, and therewith resulted in higher catalytic activity. The magnetic recovery and MB-degradation rate of Fe₃O₄/PAMAM/ZnO/TiO₂ are 93.8% and 90.8% respectively after being recyced for 5 times.

Nanopowders of 3C-SiC were synthesized at 1400°C for 3 h in Ar atmosphere via catalytic carbothermal reduction reaction method with industrial diatomite powders and phenolic resin as raw materials and ferric nitrate as catalyst precursor. XRD, SEM and TEM analysis were employed to characterize the phase composition and microstructure of the final products. The effect of temperature, catalyst content and holding time on the formation of the SiC powders was investigated. The results show that: 1) 3C-SiC can be synthesized at 1400°C for 3 h with 1.0% (mass fraction) Fe as catalyst. In the contrast, for the case without Fe catalyst, only small amount of 3C-SiC was obtained in the final products under identical condition; 2) The as-prepared 3C-SiC nanopowders are granular in morphology, and the diameters of most particles are in nano-scales; 3) Density Functional Theory (DFT) calculation results further show that the Fe catalyst played important role in breaking the Si-O chemical bond.

Novel Ag-coatings of high density and high coverage were prepared on Cu-powders via composite electroless plating. Then the phase composition, surface morphology, oxidation resistance and electrical conductivity of the Ag-coated Cu-powder were characterized by means of X-ray diffractometer (XRD), scanning electron microscopy (SEM), high temperature oxidation test and digital ohmmeter respectively. The results show that when a proper amount of nano-Ag particulate was added to the plating electrolyte, the chemical deposition of Ag-coating of high density and high coverage can be facilitated on the surface of Cu-powder, besides,such nano-Ag particulate containing electrolyte presents better plating effect than that without adding nano-Ag particulate. Furthermore, the Ag-coated Cu- powder has good oxidation resistance and electrical conductivity.

Novel (PEO-PVP)/LiI/I₂ gel electrolyte was prepared by blending polyvinylpyrrolidone (PVP) and polyethylene oxide (PEO), and then the quasi-solid-state sensitized solar cell was prepared with the electrolyte. The effect of the amount of conductive substance on the conductivity of electrolyte, interfacial recombination kinetics between TiO₂ and electrolyte, and the photoelectric performance of the DSSC was investigated. It follows that with the increase amount of the conductive substance, the recombination resistance and recombination reaction factor decrease gradually for the recombination between the light-generated electrons on TiO₂ with the I₃^- in the electrolyte, thereby the recombination reaction is facilitated, correspondingly the open circuit voltage (V_OC) of the dye-sensitized solar cells (DSSC) also reduced gradually. When the conductive substance is less than 15% (in mass fraction), the short-circuit current (J_sc) is controlled by the conductivity of the electrolyte, and the increase of the conductive substance may result in enhancement of the conductivity and the J_sc value. When the conductive substance is more than 15%, the dark current (j₀) of the DSSC becomes the dominant factor affecting the J_sc value, and the increase of the conductive substance caused increase of j₀ while decrease of the J_sc. The conversion efficiency (η) of the DSSC increases first and then decreases with the increase of the conductive substance and which reaches the optimum value of 5.6% when the amount of conductive substance is 15%.

Core/shell structured composite microspheres of sSiO₂/D-mSiO₂ composed of solid silica (sSiO₂) as core and dendritic mesoporous silica (D-mSiO₂) as shell were synthesized via an oil-water biphase stratification approach with cetyltrimethylammonium bromide (CTAB) as template, tetraethylorthosilicate (TEOS) as precursor, Triethanolamine (TEA) as catalyst and n-hexane as emulsion agent. The synthesized products were characterized by means of field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), and nitrogen adsorption/desorption measurements. As revealed by FESEM and TEM that there existed plenty of radiate-dendritic-like open meso-channels, which were perpendicular to the sSiO₂ sphere surface.The thicknesses of D-mSiO₂ shell could be controlled by adjusting the TEOS amount. Low-angle XRD analyses suggested that the mesochannles in the shells exhibit poor degree of order, and the average pore diameter was 7~9 nm. Moreover, the D-mSiO₂ shell thicknesses (5~60 nm) increased firstly and then decreased with the increase of stirring rate (50~500 r/min). Finally, the formation mechanism for the mesoporous shells with radiate-dendritic-like open meso-channels of composite microspheres was also discussed.