JOURNAL OF COLOR SCIENCE AND TECHNOLOGY
Year:2011 | Volume:5 | Issue:3|Papers Count:11

In this research, the photophysical properties of 4- (2- aminoethylene) amino - N- allyl - 1, 8- naphthalimide and its methylmethacrylate copolymer were investigated. Fluorescence spectrum of its thin film copolymer taken at different pH solutions suggest that it could be used as fluorescent pH sensors. The results showed that fluorescence emission of the polymer film dramatically decreased while pH is increased. Also, solvatochromism behavior of dye in various solvents has been evaluated. The fluorescence properties of this dye are so strongly affected by the nature of the solvent polarity in which the emission of molecule can be considered to be switched off when a solvent polarity is increased.

In different industries, protective oils are applied temporarily on the metal substrates to prevent corrosion damages. This layer should be removed before applying organic coatings. Alkali solution and solvent wash are the most frequently methods to remove oil from surface. Aforesaid methods can not remove this layer perfectly. As a result, always some residual protective oil remains on the metal surface. In this work the effect of this layer on properties of automotive phosphate layer was investigated using scanning electron microscope (SEM) and weight of phosphate layer. It was seen that oil pollution reduced the homogeneity of phosphate layer, changed the crystal shape of phosphate layer and decreased the weight of phosphate layer. In addition, the effect of residual oil on the different physical-mechanical properties of coating systems was investigated. It was seen that residual oil improved bending, cupping and impact properties of coating due to diffusion of the residual oil in coating layer. In the other hand, corrosion resistance decreased because of adhesion failure.

Human visual system is able to distinguish numerous numbers of colors. However, this matter has been always raised how the people would like to categorize colors into main clusters and which words, they usually use to name them. In this issue, Kay and Berlin’s researches are the most important studies. They claimed industrialized human societies usually categorize the colors into 11 main groups, including: Black, White, Gray, Red, Green, Blue, Yellow, Pink, Orange, Brown and Purple. This paper is a review on color naming to introduce and discuss the concept of color naming and color categorization, the experimental procedure of color naming, and the results presented in several investigations. Dividing color spaces into fuzzy sets for color categorization, establishment of WCS and MACS research centre, experiment done for color naming, naming array, color naming data analysis, some samples of WCS languages and universal color naming for all languages are reviewed.

Aqueous colloidal sol-gel method was used to produce iron-zircon coral pink pigment. Simultaneous Thermal Analysis (STA), X-Ray powder Diffractometry (XRD), and Fourier Transform Infra-Red (FTIR) spectroscopy were used to investigate the formation mechanism of this pigment. The catalytic effect of iron in promoting zircon formation was also studied by making a comparison between a sample including 30 mol.% of iron and samples free of iron. It was demonstrated that addition of iron promoted the formation of zircon in rather lower temperatures. The effects of iron content entering zircon structure on its structural characteristics were examined. These studies confirmed that the process of zircon formation have been drastically changed by increasing in iron content. It was shown that transformation of zirconia structure from tetragonal to monoclinic, that was suggested to happen before formation of zircon, was eliminated by adding more than 20 mole percent iron. This phenomenon can be related to Hedvall effect, which is caused by the amount of iron in entering the tetragonal structure of zirconia. Finally, colorimetric parameters of the enameled samples were measured by the CIE colorimetric method.

In recent years, numerous studies have been conducted on monascus growth media to optimize different conditions of pigment production in this fungus. In this research, biomass and pigment production of Monascus purpureus strain DSMZ 1603 was studied using three levels of sodium nitrate (1.5, 3 and 4.5 g/l) and five levels of saccharose (75, 100, 125, 150 and 175 g/l) in a factorial design and five levels of zinc sulfate (0, 5, 10, 15, 20 mg/l) in a completely randomized design. Treatments were cultured in a broth medium at 25 oC and 150 rpm rotating shaker. The results showed pigment production was enhanced significantly by increasing the saccharose level whereas the effect of sodium nitrate was not significant on the pigment production. The highest rate of pigment production was induced in 175 g/l saccharose with 3 g/l sodium nitrate. The highest biomass produced in the medium contained 175 g/l saccharose with 4.5 g/l sodium nitrate. The results showed pigment production decreased significantly by increasing the levels of zinc sulfate while the highest rate of pigment production was induced in the medium without zinc sulfate.

In this study, the dye removal of acid and metal complex dyes (Acid Black 26 and Acid Yellow 59) by electrocoagulation process using aluminum electrodes were studied at single and binary systems. The effect of several operating parameters such as conductivity, current density, initial dye concentration and pH on the electrocoagulation process was studied. The Beer-Lambert’s law has been applied to the binary system analysis by spectrophotometer and measurements at two wavelengths for each sample have led to determine the concentration and extinction coefficient of the two components at their maximum wavelength. It was found that increasing the current density has a positive effect on color removal efficiency. It was also indicated that increasing conductivity, did not have a significant effect on color removal efficiency but decreased the cell voltage. The most important result is that the data for single and binary systems are too close and it can be concluded that the electrocoagulation process is an effective method to remove acid and metal complex dyes from single and binary systems

Titanium dioxide is a pigment with the highest consumption amongst all other white and colored pigments in different industries which solely is produced from mining procedures and its consumption in Iran is thousands of tons per annum. In the present research, two new synthetic white pigments based on organic and inorganic materials were evaluated for their potential for substitution of TiO2 in white textile printing formulations. According to the results, both synthetic white pigments were capable of full substitution of TiO2 in textile printing formulations. Rubbing, washing and light fastness of printed patterns using synthetic white pigments were acceptable and inorganic white pigment showed very high stability even up to 600oC whilst organic white pigment could only withstand temperatures of up to 190oC.

In this research, novel hybrid nanocomposite containing iron modified titanium dioxide and tetraisoindole organic pigment has been synthesized and characterized. Modified nanoparticles and hybrid nanocomposite have been characterized by X-ray diffraction (XRD), FT-IR spectroscopy, energy dispersive X-ray (EDX) analysis, BET surface area determination, diffuse reflectance spectroscopy, simultaneous thermal analysis (TG, DTA) and transmission electron microscopy (TEM). The results confirmed the formation of the hybrid nanocomposite containing iron modified titanium dioxide and tetraisoindole organic pigment with the pure anatase phase. The TEM micrograph displayed that particle sizes of the hybrid nanocomposite were about 25 nm. The band gap energy of the hybrid nanocomposite was about 2.53 eV that has been decreased significantly in comparison with modified titanium dioxide nanoparticles (3.10 eV) and pure titanium dioxide (3.66 eV). Hence, synthesized hybrid nanocomposite with absorption edge in the visible region is much appropriate for optical applications of photocatalyst and photovoltaic under solar light irradiation.

In this research, coagulation process efficiency using three coagulants poly aluminum chloride (PACl), alum and ferric chloride in the presence of coagulants aid anionic polyelectrolyte and kaolin were studied for removal of synthetic wastewater containing reactive blue 19 dye in lab scale. The effect of main parameters such as pH, coagulant concentration, initial dye concentration and presence of coagulants aid has been investigation. The results showed that the best efficiency for dye removal using three coagulants was acheived in neutral pH. Under this condition optimum concentrations of poly aluminum chloride, alum and ferric chloride was 200mg/L, 300mg/L and 400mg/L and their related removal efficiency was 91%, 92% and 81% respectively.Addition of polyelectrolyte as a coagulant aid with ferric chloride slightly increased process efficiency, whereas adding polyelectrolyte with alum and poly aluminum chloride slightly decreased efficiency. Adding kaolin as a coagulant aid with PACl increased process efficiency about 5%, whereas adding kaolin with alum slightly decreased process efficiency and can be ignored also, in the case of ferric chloride no significant effect on process efficiency observed in the presence of kaolin. Finally regarding above mentioned results, coagulation can be a robust alternative method for the treatment of reactive dye containing wastewaters.

In this paper, the adsorption of Acid Yellow 36 (AY36), and Acid Red 73 (AR73) onto Pine Cone (PC) was investigated in aqueous solution in a batch system with respect to initial dye concentration, pH, contact time, temperature, inorganic anions (salt) and biosorbent doses at 25oC. Surface studies of PC were investigated by Fourier transform infrared (FTIR). Studies of dye concentration and salt effects exhibited that dye removal percentage by PC was decreased. The results indicated that acidic pH supported the adsorption of this dyes by PC. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetics data. The experimental data fitted well to the pseudo-second - order kinetics model for both dyes. Equilibrium isotherms were analyzed by Langmuir and Freundlich adsorption models. It was found that the isotherm data of AY36 and AR73 followed langmuir and Freundlich isotherms, respectively. Effective desorption of dyes were showed that adsorption of dyes on PC is physical process. The results indicate that PC could be employed as effective biomaterial for the removal of dyes from textile wastewater