JOURNAL OF COLOR SCIENCE AND TECHNOLOGY
Year:2010 | Volume:4 | Issue:2|Papers Count:8

Corrosion inhibition effect of 2-mercaptobenzimidazole (MBI) and 2-mercaptobenzoxazole (MBO) compounds on steel in hydrochloric acid solution was investigated by electrochemical impedance spectroscopy (EIS) and it was observed that both of these compounds have corrosion inhibition effect on mild steel. Evaluation of electrochemical behavior in test solutions showed that by increasing the immersion time from 15 to 300 min corrosion resistance of samples are increased and at the same immersion time MBI have the better corrosion inhibition in comparison to MBO. Quantum chemical calculations were performed using Hyperchem7 software for MBI and MBO. The results of calculations showed superior inhibition efficiency of MBI in comparison to MBO, which could be attributed to the more negative charge of pyrole-like nitrogen atom in comparison to oxygen atom. This can cause easier protonation and consequently adsorption on the metal surface occurs easily.

In this work nano silica was treated by an amin silane at different pH conditions and analysed using different techniques. It was found that the pH of treating bath highly affected the grafting of silane on the surface leading to grafting ratios between 29 and 58 percent. The zeta potentials changed from -7.1 mv for pristine silica to +5.5 mv and +18.01 mv for the lowest and the highest grafted particles respectively. The results showed that, the sample with higher grafting has better dispersion stability in solvents with higher hydrogen bonding parameter and lower polar parameter. The higher mechanical properties of the nano clear coats using a polyurethane filled with these particles may confirm the better dispersion and possibility of a physicochemical interaction between the surface modified silica and the matrix. The tensile strength, elongations at yield and break and micro indentation hardness as well as the Young modulus were used to show the improvement achieved in properties of modified particles containing resin.

Dianilides 1 and 2 derived from concerned substituted anilines were transformed to corresponding coupling components 3 and 4 in good yields using melted AlCl3.These compounds were coupled with diazotized aryl and heteroaryl amines to give to corresponding azo dyes 5a-d and 6a-d. The structure of the new azo dyes was confirmed by UV-Vis, FT-IR, 1H NMR spectroscopic techniques. The solvatochromism of dyes was evaluated with respect to wavelength of maximum absorption (0max) in six solvents: acetic acid, ethanol, chloroform, acetonitrile, dimethyl sulfoxide and dimethyl formamide. The color of the dyes is discussed with respect to the nature of cyclic and heterocyclic ring and substituents therein. The effects of acid and base on the visible absorption spectra of the dyes are also reported.

In this research, a lithography ink formulation based on the Maleic and Alkyd resin has been prepared and its rheological parameters such as viscosity vs. shear rate, thixotropy cycle, storage and loss modules and dynamic viscosity were studied. It was observed that viscosity values augmented severely by increasing the pigments concentration and reducing the particle size distribution. Time dependence thixotropy values were significant in samples containing small particle size and high pigment concentration. Structural networking and association of carbon black particles as well as particle-particle and particle-binder interaction are reasons for this behavior. Storage and loss modules were increased with reduction of particle size and/or increasing of pigment concentration. Besides, the differences between dynamic parameters in low frequencies were obvious.

This study provides information on the application of the Fenton process as an advanced oxidation method for the treatment of wastewater containing an azo reactive dye (C.I. Reactive Red 120). To establish cost-efficient operating conditions for potential application of Fenton oxidation process, the influence of the main operating parameters such as iron sulfate and hydrogen peroxide doses, solution pH, temperature, initial dye concentration and presence different concentrations of sodium chloride and sodium sulfate have been studied systematically in a laboratory scale. The obtained results showed that the best pH value for decolorization of dye solution was 3. The decolorization of RR120 enhanced with the increasing of reaction temperature but decreased as a presence of chloride and sulfate ions. The increase of Fe2+ and H2O2 doses accelerated the color and COD removals until a point where further addition of Fe2+ or H2O2 became inefficient and unnecessary. The result indicated that over 99% color removal and up to 74% COD removal can be obtained by Fenton’s oxidation.

This research aims to create the selfcleaning property on wool/ polyester fabric using TiO2 nano-particles. In order to provide the fabric with higher absorption of nanoparticles, the oxidation of wool with KMnO4 were carried out. The crosslinking agent namely butane tetra carboxylic acid (BTCA) was used to stabilize the nanoparticles on the fabric surface. To investigate the properties on the treated fabric, discoloration of Methylene Blue and Acid Blue 113 stains, water drop absorption, crease recovery angle, yellowing and bending of the fabric were examined and the results reported. Furthermore, the FT-IR spectrum of some samples was analyzed. The changes in color differences for different samples showed that an appropriate discoloration achieved on the fabric samples treated with TiO2 after UV radiation. Also the reflectance spectrum of samples was investigated and the results confirmed the UV absorption by TiO2 nano particles that protect the fabric from yellowing.

One of the recurring problems observed with most of commercial anionic reactive dyes for dyeing nylon was the low degree of exhaustion and fixation. In this paper, a number of attempts were made to improve the fixation efficiency of an anionic reactive dye, Procion Rubine XL+, on modified nylon. This dye was selected for further study since, from the previous study, under non-optimised conditions fixation efficiency was particularly poor and therefore offered more scope for significant and readily observable improvements. The following process variables were studied; (a) effect of added alkali; dye was exhausted at pH 4 and then alkali added, (b) effect of added electrolyte, The addition of alkali and electrolyte during dyeing resulted in reduced dye fixation.