To improve the distribution of ultraviolet absorbers (UVAs) on coating surface, novel fluorinated triazine UVAs with surface enrichment property were developed. The structure of these compounds was characterized by FT–IR, 1H NMR, 13C NMR and HRMS. UV–Vis spectroscopy results indicate that these new UVAs possess an outstanding UV absorption ability, as verified by quantum calculation. Contact angle measurements show that PVC coating mixed with these novel UVAs exhibit excellent hydrophobicity and oleophobicity. Attenuated total reflection Fourier-transform infrared spectroscopy and X–ray photoelectron spectroscopy suggest that the surface enrichment ability of these modified UVAs are improved almost four times.Compared with traditional ultraviolet absorbers, the fluorinated ultraviolet absorbers with tail can spontaneously travel to material surface.Download high-res image (199KB)Download full-size image

Research on corrosion behaviour of zinc in natural sea water without and with fucoidan was carried out by potentiodynamic polarisation test and electrochemical impedance spectroscopy (EIS). The results revealed that fucoidan serves as a good inhibitor for zinc in sea water. Polarisation curves suggested that corrosion potential values shifted to the positive ones after adding inhibitor and fucoidan retards anodic reaction more. Thus, fucoidan can be acted as anodic inhibitor. EIS results showed two phenomena including a charge transfer and an adsorption film. The corrosion inhibition of fucoidan was further confirmed by the scanning electron microscope (SEM) and atomic force microscope (AFM) analysis. Langmuir’s adsorption isotherm was found the appropriate adsorption model.

3-level-3-factor robust parameter design and variance analysis were employed to optimize the formulatimemon process of antimony doped tin oxide (ATO) particles with high conductivity. Results indicated that optimized formulation parameters were as follow: Sb doped content of 11 mol%, calcination temperature of 800 °C and calcination time of 0.75 h. For the ATO powder prepared under the above optimal condition, the conductivity of ATO in the validation experiment was 7.6511 S cm−1, which was almost close to the predicted value, and the ATO powder had smaller diameter, higher transmittance in visible region as well as better thermal insulating properties than its counterparts.

•Uniform design was used to study waterborne alkyd resin.•The optimum formulation conditions of the resin were determined.•All resins exhibited excellent stability and water-solubility.In order to optimize the formulation of waterborne alkyd resin preparation, a 9-level-3-factor uniform design and regression analysis were firstly employed to evaluate the effects of the selected variables including fatty acid content (L), hydroxyl/carboxyl molar ratio (r) and molar ratio of polyatomic acids (f) on set-to-touch time of film. The results indicate that the data can be adequately fitted with a first-order polynomial model, and the main factors successively affecting set-to-touch time are fatty acid content (L) and molar ratio of polyatomic acid (f). The above model is proved valid within the designed scopes of the investigated formulation parameters by validation experiments. The optimized formulation parameters for waterborne alkyd resin synthesis is predicated as follows according to the model, i.e. L is 30%, r is 1.2, f is 2.2, the result set-to-touch time is 43 min, which significantly shorten the drying time.

Effects of pH value, chloride ion concentration and alternation of wetting and drying time in acid rain on the corrosion of 35CrMn and Q235 steel were investigated through the measurement of polarization curves, electrochemical impedance spectroscopy, x-ray diffraction, and quantum mechanical calculations. The corrosion rate of 35CrMn and Q235 steel increased with decreasing pH values of the simulated acid rain, whereas the corrosion potential of 35CrMn and Q235 steel became more negative. The impedance became higher and the corrosion rate decreased with increasing test time. The dissolution rate of samples increased with chloride ion concentration. Results suggested that the corrosion rate of 35CrMn steel was obviously lower than that of Q235 steel for a more compact rust, α-FeOOH. Quantum chemical calculations further revealed that the increase in corrosion rate of the steel resulted from pitting corrosion caused by the corrosive chloride ion.