نشریه علوم و فناوری رنگ
سال چهاردهم شماره 2 (پیاپی 52، تابستان 1399)

In this study, the response surface method (RSM) of the central composite design model was used to optimize the extraction of dyes in madder plant root by a shaker-incubator. The optimum conditions for the assessed parameters including pH, time and temperature was 6.57, 63.88 min and 47.46 °C, respectively. Each experiment’s response was determined by assessing light absorption intensity at 413 nm. Experiments to obtain optimum condition out of the chosen model show that there is a very insignificant difference between the model’s absorption and our experimental method. To prepare powder of the extracted dye material, we extracted the dye through four steps. The resulted solution was condensed by a rotary machine in vacuity. Then it was added to a formulation that encompasses filling materials and superficial active materials agents. The results imply that the prepared powder can dye wool thread which in turn showed stable properties involved wash fastness of 4-5, light fastness of 4-5 and rubbing fastness of 3-5.

Engineering and biological properties of pyrimidines have stimulated chemists to develop the chemistry of these compounds as dyes and organic-metal complexes. Metal complexes of monoazo compounds are principally useful as metal complexes for dyeing of protein, polyamide and engineering materials and Countless shades from greenish yellow to deep black can be generated, depending upon the metal, the dye ligands, and the combination of dye ligands in mixed complex dyes. In this research for the first time a number of new azo dyes were synthesized by coupling 4, 6- dihydroxy pyrimidine with diazotized heterocyclic aromatic and nonheterocyclic aromatic amines. Then one of the synthesized dyes and also 4, 6-dihydroxypyrimidine was used as ligands to preparing some new Azo and Azo-metal (Cupper (II), Nickel (II) and cobalt (II)) complexes. Studies have shown that some metals such as Copper (II) reacts with the other nitrogen and oxygen atoms in the pyrimidine ring at a ratio of (3: 2) in addition to the covalent coordination with the azo group and the hydroxy pyrimidine group. The structures of all synthesized compounds were confirmed by instrumental and elemental analysis (C.H.N.). The antibacterial activity of the selected products was examined. Some products contain donor group like methyl exhibit promising activities.

The influence of adding benzimidazole (BIA) and benzothiazole (BTA) as corrosion inhibitors to the acidic solutions on corrosion behavior of silane coatings was investigated using electrochemical impedance spectroscopy (EIS), polarization test, Field Emission Scanning Electron Microscopy (FESEM) and electrochemical noise method. The results of EIS, polarization and electrochemical noise showed that the presence of inhibitors reduce severe corrosion attacks on metals' surface leading to obtain uniform silane coatings. Corrosion current density was reduced from 108 µA/cm2 in the absence of inhibitor to about 64 and 2 µA/cm2 in the presence of BIA and BTA, respectively. FESEM images confirmed that presence of inhibitors provides uniform corrosion products. Moreover, EDS Results well confirmed previous electrochemical results by claiming that benzothiazole surface adsorption is higher than benzimidazole.

Today, the treatment of industrial wastewater, including textile is in a high importance. Actually the use of nanomaterials in the removal of wastewater from sewage has attracted widespread attention in recent years. The color of the Indigo is one of these pollutants. In this study, optimum nano fiber chitosan-itaconic acid was prepared using experimental design and in the following adsorption of Indigo dye wastewater treatment and the study of its kinetics and its isotherm was investigated. X-ray diffraction (XRD), Field Emission Scanning Electron Microscopes (FESEM), Infrared Fourier Transform (FT-IR), Vibrational Sampler Magnetic Meter (VSM) and thermal gravimetric analysis (TGA) are also used to study synthesize nano-fibers. Also, the effect of the initial concentrations of pollutants for absorbance, contact time, temperature and pH were investigated.In this study, the optimal concentration of Indigo 100 ppm, optimal time of 45 minutes and optimal pH 3 was obtained. The mechanism absorption of chitosan-itaconic acid follows the pseudo first-order kinetics and Freundlich isotherm model.

In this research, acid orange7 dye removal is investigated by using hen feather and its carbon as adsorbents. The effect of different parameters such as pH, temperature, initial concentration of dye adsorption dosage and contact time was studied. The results illustrated that the maximum amount of dye removal could be obtained under pH of 3, ambient temperature, dye concentration of 20 mg/L and retention time of 90 min using 30 mg/L of adsorbent. The maximum removal percentages and maximum adsorption capacity were 89.37, 96.41% and 134.23 mg/g, 157.11mg/g, respectively for hen feather and its carbon. The experimental results have been fitted well by the Freundlich isotherm model with R2=0.969 and 0.966 for hen feather and its carbon respectively.Also acid orange7 dye removal follows the pseudo second-order kinetic equation and it's a spontaneous process.

In this study, colored glass was prepared using layer coating with silver nanostructures such as nanowire, spherical nanoparticles and dendritic. Silver nanowires were prepared by a solvo-thermal and polyol combination method with different molar ratios of poly-vinyl-pyrrolidone and silver nanoparticles by polyol and chemical reduction methods. The silver dendritic nanostructure was made by dip coating method in different sizes. Characterization of silver nanostructures was accomplished by X-ray diffraction, scanning electron microscopy and ultraviolet-visible spectroscopy. The cleaned glasses then were coated by immersion in a solution of silver nanostructures. In order to fix the color of the glasses after the coating operation, the glasses were heated at 700 °C. The colors of the glasses were in the yellow color range. The glass color characteristics, including the color parameters and color coefficients and the dominant wavelength, were studied using a spectrophotometer and color triangle. It was observed that the color coefficients (L*a*b*) for the same concentrations and different morphologies of the nanostructures were different and varied from (55.87, -8.39 and 9.94) for nanowires to (-66.85, -20.65 and 18.91) for dendritic and (46.69, -1.65 and -30.62) for nanoparticles. The effect of the concentration and size of nanostructures on the color of the glasses was also investigated.

Since 1980s, visible light initiating systems have been highly regarded due to the overcome of UV initiating systems challenges. In this study, a new visible light three-component photoinitiating system (PIS) consisted of safranin O (SFH+), thiol derivatives and diphenyl iodonium salt was used for the free radical photopolymerization of a diacrylate monomer (SR349). Conversion and rate of polymerization of SR349 were determined by using RT-FTIR. Results showed that the new PIS could be used as an efficient PIS for free radical photopolymerization. The final conversion of photopolymerization reaction of the acrylate system was found to be more than 75%. In addition, the initiating mechanism of the three-component PIS was studied by using laser flash photolysis (LFP). It was shown that radicals were produced by a sequential reaction between photosensitizer and coinitiators. Also, photosensitizer would be reproduced by a photocyclic reaction behavior.