PROGRESS IN COLOR, COLORANTS AND COATINGS
Year:2017 | Volume:10 | Issue:2 |Papers Count:6

several silicate materials were plasma sprayed and characterized by the authors in recent years from the point of view of their chemical and phase compositions, microstructure and mechanical as well as thermal properties. The present work is concerned with selected dielectric properties of these deposits. Synthetic mullite and steatite as well as natural olivine-forsterite were plasma sprayed using the water-stabilized plasma system (WSP® ). The deposits were striped-out, ground and polished to produce samples in form of plates with a smooth surface. Part of samples was later annealed in air. These samples-after coverage by metal electrodes functioning as monoblock capacitors-were tested in the alternative low voltage electric field to measure capacity and loss factor in the frequency range from 200 Hz to 1 MHz. Relative permittivity was calculated from the measured capacity. Volume resistivity was measured in the direct electric field. It is shown that the relative permittivity of as-plasma sprayed silicates is less stable compared to bulk in the whole studied frequency range. However, thermal annealing modifies the structure much closer to the sintered bulk which is also reflected in dielectric properties. Insulating ability of plasma-sprayed silicates with and without annealing is discussed in consequence with chemical changes and phase changes induced by annealing. Prog. Color Colorants Coat. 10 (2017), 105-114© Institute for Color Science and Technology.

in corrosion protection study, it is important to develop economically attractive test method for mitigation of corrosion damage of coated structure. Faster predication of protective behavior of any coating is a big challenge for the coating industries. In present work, in-house waterborne anticorrosive coating system was selected for study. The corrosion protection of coating evaluated as per ISO12944-C3-High which includes salt spray (ISO 9227, 480 h) and quick condensation test (ISO6270, 240 h). The exposure period was extended up to 1000 h for further monitoring of deterioration of selected coating system. In view of early predication of coating performance, different accelerated test exposure conditions were designed in laboratory, such as thermal aging in distilled water (50° C and 80° C), chemical immersion (H2SO4 and NaOH), wet-dry cycle and thermal cycling. The corrosion protection properties of coating exposed to ISO 12944-C3-High environment was compared against the lab designed test method using electrochemical impedance spectroscopy (EIS) technique. The deterioration rate of coating was measured by evaluating polarization resistance (Rp), water uptake (w) and break point frequency (Fb). The coated specimens after exposure were also evaluated for loss of adhesion strength. Results showed that thermal aging in distilled water at 80° C is the most severe exposure condition as coating system loses its protective behavior in relatively short period. Prog. Color Colorants Coat. 10 (2017), 93-104© Institute for Color Science and Technology.

polypropylenes loaded with different alkyl ammonium-modified montmorillonite are prepared to utilize a melt-mixing technique in various ways. Two types of polypropylene and compatibilizer are incorporated to improve the dispersion of various types of nanoclay and the dyeing behavior of the nanocomposites with various disperses, acid and basic dyes were studied. For the first time, the aim of this study was to investigate the effect of operational and material parameters in dyeing behavior and color buildup of producing nanocomposite due to better understanding of the dyeability mechanism of PP/nanoclay composite. The extent of exfoliation and dispersion of the nanoclay in PP was analyzed by XRD and TEM analytical techniques and the dyeability was studied through color build up and spectrophotometric measurement. The results showed that the mixing condition had no significant effect on dyeability. The lower the molecular weight of polypropylenes and compatibilizer caused the better the dyeability. The most intercalated nanocomposite also showed better dyeability and within various types of dye, disperses dye showed better dyeability. All things considered, it is appeared that between the two mechanisms suggested for dyeing improvement in the PP/nanoclay composite, the dominant mechanism is creating the path. Prog. Color Colorants Coat. 10 (2017), 73-84© Institute for Color Science and Technology.

nickel films of 150 nm thickness were deposited on 304 stainless steel and post annealed under flow of nitrogen at different temperatures. The prepared samples were corrosion tested in 1. 0 M H2SO4 solution using potentiodynamic polarization technique. Crystallographic and morphological structure of the samples were analyzed by X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively, before corrosion test, and scanning electron microscope (SEM) after corrosion test. A clear correlation between the physical analyses (XRD, AFM and SEM) and the potentiodynamic results is achieved. The variation of corrosion resistance of the samples showed that the optimum annealing temperature is 673 K. Prog. Color Colorants Coat. 10 (2017), 85-92© Institute for Color Science and Technology.

in this paper, the sorption activity of Salvadora Persica fine particles provided from internal natural resources in Iran with respect to Crystal Violet, Basic Violet-16 and Basic Blue-41 dyes is investigated. Salvadora Persica particles were modified and prepared via particle size reduction and they were characterized by CHNS, XRD, SEM and FT-IR analysis. In the batch system, the influence of pH, adsorbent dosages and dye initial concentration was investigated. The results of isotherm and kinetics studies show that the Langmuir isotherm and pseudo-second order kinetic have better correlation with the experimental data. Calculations of thermodynamic parameters show negative Gibbs free energy (Δ G) values or spontaneous reaction, the enthalpy (Δ H) changes shows the exothermic process and values of entropy (Δ S) indicate low randomness at the solid/solution interface during the uptake of dyes. So, these locally available cheap adsorbents for the removal of basic dyes from the aqueous solution have high efficiency and can also be utilized for other water pollutants such as toxic elements. Prog. Color Colorants Coat. 10 (2017), 115-128© Institute for Color Science and Technology.

an ecological approach has been obtained by using natural dyes and mordants for dyeing process. Silk fabrics were dyed using natural mordants including powder of sour pomegranate, sweet pomegranate and their mixture. A beautiful red color was obtained using theses mordants. The color of dyed silk fabrics was investigated in CIELab (L*, a* and b*) and K/S values. Finally, all dyed fabrics were tested for wash and light fastness properties as per ISO standard test methods. The results of using biomordants for silk dyeing were comparable with that of metallic mordants in terms of color strength and fastness properties. Pomegranate extract as biomordant produced red color with medium fastness properties and thus offer full potential to replace metal salts in silk dyeing process. Prog. Color Colorants Coat. 10 (2017), 129-133© Institute for Color Science and Technology.