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It’s generally accepted that the transport of lithium ions in solid polymer electrolytes exists mainly in the amorphous regions, thus the research has focused on reducing the crystallinity to obtain high conductivity at room temperature. However, the point has been challenged: crystalline systems can provide a better ionic conductivity. In this paper, PEO/LiClO4 polymer electrolytes with different lithium-oxygen ratios were prepared by melt-blending. The results show that [EO]/ [Li+] = 3 system has higher ionic conductivity, 4.26×10-6 S/cm, more than twice as that of [EO]/ [Li+] = 4 system. DSC and XRD results show PEO3:LiClO4 crystalline phase present in both systems, the crystallinity of [EO]/ [Li+] = 3 system is higher. It illustrates the generally accepted mechanism is not suitable for these systems, suggesting the high conductivity of [EO]/ [Li+] = 3 system is due to the unique crystal structure of PEO3:LiClO4. Besides, as the crystallinity increases, the tensile strength of [EO]/ [Li+] = 3 system increases greatly, to 1.43 MPa. In addition, because of the high melt temperature of PEO3:LiClO4, the electrolytes will gain excellent heat resistance. In summary, this paper provides a new idea to prepare polymer electrolytes with high ionic conductivity, improved strength and excellent heat resistance in large scale.

Cu-Ni-W alloy coating was electroplated on the surface of mild steel and the effect of Cl- concentration on its corrosion behavior was evaluated in this paper. Polarization techniques and electrochemical impedance spectroscopy (EIS) have been used to investigate the corrosion behavior in aqueous solution contain various Cl-. The results showed that The increased Cl- is prejudice for the Cu-Ni-W coating from 0.01 to 0.3 mol/L, and the critical value of Cl- content is 0.3 mol/L, the coating corrosion present better resistance when immerse in the solution with Cl- content exceeds the critical value or more .

Effect of grain size and Cl- concentration on corrosion behavior of Cu was investigated by using a series of electrochemical analysis in borate buffer solution (pH=8.40).The results indicated that in all cases, the Mott-Schottky plots of the passive films on the surface of Cu were linear with negative slop, and showed behavior of the p-type semiconductor.With the decrease of the grain size and the increase of anode passivation potential, the acceptor density (NA) of the passivation film on the surface of Cu was reducing. As the concentration of Cl- in the medium solution was heightening, the acceptor density (NA) of the passivation film on the surface of Cu was increasing.

Ni–B4C composite coatings on carbon steel substrates with various contents of B4C nano-particulates were prepared by electrodeposition in Ni plating bath containing B4C nano-particulates. Microhardness, Scanning Electron Microscopy (SEM), Tafel polarization and Electrochemical Impedance Spectroscopy (EIS) measurements were used to compare pure nickel coatings and Ni–B4C composite coatings. Pure Ni coating microhardness is lower than that of Ni–B4C coatings and the microhardness of the composite coatings increases with the increase of the content of B4C nano-particulates. The effects of various contents of B4C nano-particulates on the corrosion resistance were investigated and it was found that the best anti–corrosion property of Ni–B4C composite coatings is at 6 g/L B4C in the bath formulation.

Montmorillonite was introduced into the multicomponent epoxy resin by using the intercalation polymerization. Intercalation effect of epoxy/montmorillonite composite system and the influence of the addition of montmorillonite on the glass transition temperature (Tg), mechanical properties and barrier of H2S to coating under high temperature and pressure conditions were investigated. The results showed that it was easy to intercalate epoxy resin into the organic montmorillonite layers, and the interlayer spacing of Montmorillonite was further swelled. In addition, the epoxy/montmorillonite nanocomposite coating with intercalated/ exfoliated structures were prepared. Compared to pure epoxy coating, the heat resistance and mechanical properties of epoxy/montmorillonite nanocomposite coating were slightly improved, and the barrier efficiency to H2S was substantially increased under high temperature and pressure oil-gas environment.