JOURNAL OF COLOR SCIENCE AND TECHNOLOGY
Year:2011 | Volume:5 | Issue:2|Papers Count:12

In this study the potential of canola stalks to ramove of reactive Remazol Black B from artificial aqueous solution were studied. Adsorption isotherm study using various concentrations showed that the Remazol Black B absorption was well described by both Langmuir and Freundlich isotherms, but Langmuir model with a higher correlation coefficient was better fitted than Freundlich model. Using Langmuir model, the highest adsorption capacity was found 32.8 mg/g. Kinetic study showed that the adsorption of RBB of canola stalks obeyed the pseudo-second order kinetic model. The adsorption capacity of canola stalks was higher than that obtained for other lignocelluloses raw materials, and it could be applied as a cost-effective absorbent for treatment of wastewater containing of Remazol Black B.

Copper (II) and cobalt (II) complexes with dipicolinic acid ligand have been synthesized by a novel and facile synthetic rout using amino acid L-lysine. Characterization, structural and colorimetric studies of synthesized complexes were carried out by single-crystal X-ray diffraction, elemental analyses, colorimetric analysis, thermal analysis and FT-IR, UV-Vis and diffuse reflectance spectroscopies. Results showed that copper (II) complex, has the polymeric structure of one-dimensional (1D) zigzag chains, whereas in the cobalt (II) complex, cobalt ions occupied two different octahedral positions. Dipicolinic acid ligands lie approximately on ab crystal planes and p-p interactions of pyridine rings formed 3-D networks. Results showed that amino acid did not participate in the structure of complexes and assist the formation of multi dimensional structures. Synthesized colored complexes have favorite color properties and high solubility in water and polar solvents due to carboxylate functional groups and the total net charge of complexes.

Sorption isotherms of two acid dyes, Blue 127 and Green 25 on nylon 6 fibers were studied at 90 and 98oC, respectively. A remarkable deviation from Langmuir isotherm was obtained for both dyes. Performance of Dual-Mode sorption model which consists of Langmuir mechanism and Nernst model was tested. Dual-Mode fitting was appeared to be in good agreement with the experimental data rather than Langmuir. In addition, the sorption capacity of fiber from measuring the amino end-group content and that calculated from Langmuir isotherm was compared. The results confirmed that the adsorption is not limited only to the sitting mechanism and there are the other sites involving in the adsorption. Studying the temperature effect on Dual-Model isotherm showed the total adsorption capacity of fiber is decreased by increasing the temperature. However the most part of total sorption was still followed as Langmuir isotherm.

In this research, the miniemulsion polymerization method was used to prepare a hybrid polymer system based on an alkyd resin and an acrylic monomer. For this purpose a medium oil length alkyd resin, butyl acrylate monomer, sodium lauryl sulphate as an emulsifier, cetyl alcohol as a miniemulsion co-stabilizer and potassium persulphate as an initiator were used. To prepare miniemulsion an ultrasonic mixer was used. It was found that the resulting polymer had a broad molecular weight distribution and a bimodal particle size distribution about 138 nm and 550 nm. Furthermore, two glass temperature were observed (at -18°C and -41°C) which showed the presence of two distinct components in final resin. One of them obtained from grafting of acrylic monomer on alkyd resin via reaction with double bonds of fatty acid of alkyd resin and the other one from homopolymerization of acrylic monomer in the continuous phase (water) which is confirmed with results obtained from GPC.

In this research nanocrystalline cobalt-doped zinc oxide pigments were prepared via solid reaction and combustion, using glycine as fuel. Obtained powders were characterized by X-ray diffraction, fourier transformation infrared, scanning electron microscopy, transition electron microscope and diffuse reflectance spectroscopy. X-Ray diffraction patterns showed the formation of wurtzite single phase in combustion reaction whereas in the case of solid reaction pure structure appeared after calcinations at 1000oC. Crystallite size of the combustion sample was significantly reduced in comparison with the solid reaction samples. Morphological studies using scanning electron and transition electron microscopy revealed that combustion method changes particle size to nano scale ranging from 50 to 100 nm. The colorimetric studies showed a broad reflectance band around 530 nm (green region) for all samples. These results indicated that the samples obtained by combustion reaction have deep green color properties than solid reaction ones. It can be related to smaller crystallite size of nanoparticles in combustion reaction. Fourier transformation infrared results indicated that the main broad band assigned to the zinc-oxygen bond.

In the present research, poisoning phenomenon of catalyst that applies for total oxidation process of volatile organic compounds (VOCs) has been studied. The VOCs emitted to workshop environment of printing industries from rapid drying of printed papers. Solvent of printing inks contain silica organic compounds that poisoned the catalyst. Pt/g-Al2O3 catalyst is able to remove around 100% of organic pollutants in workshop atmosphere by total oxidation process. The process is carried out at the temperature more than 623K in a plug flow reactor. But poison, such as silica organic compounds, deactivates the catalyst so fast. Available laboratorial, pilot and industrial information were investigated and compared to understand the deactivation process, its main parameter (s), and scale up ability of data. Results showed that duration of process was the main parameter and prior to others.

Nanoclay, Cloisite 20A, in 0, 0.5, 1, 2 and 3 w% were dispersed by mechanical and Ultra sonic mixing method in polyester-ether vehicle in the same conditions. Then solvent free aromatic isocyanate hardener was added in the above specimens stoichiometrically in order to synthesize nanocomposites. The X-Ray Diffraction (XRD) analysis and Transmission Electron Microscopy (TEM) indicate that the nanoclay has intercalated in the 100% Solid Polyurethane. Results of Dynamic Mechanical Thermal Analysis (DMTA) show that nanoclay content increases the thermal transition (Tg) for nanocomposite specimens, while the storage modulus decreases due to decrease of cross linking density of nanocomposites.

Pure bitumen which is used as a binder for asphalt has some functional limitations. Many works have been done to resolve these problems to develop better bitumen. The polymer modifiers are the most popular substances for these kinds of transformations. Many research approaches have been pursued to improve the bitumen quality as well as production cost reduction. Polysulfide polymer (PSP) which also can be gotten by synthesizing of Petrochemical Wastes (wPSP), is used as a modifier for bitumen in this research. Different weight percentages (1, 3 and 5) of PSP were mixed with Bitumen 60/70 from Tehran Refinery and then physical and mechanical properties of the results were experimented and compared. The results were shown that PSP was dispersed homogenized and increased the penetration, the softening point and also the penetration index. It also decreased the flashing point while the ductility and weight loss percentage stayed the same. The blend viscosity increase was the other result of this research. Using wPSP as oppose to PSP not only was more efficient but also could help to save the environment better. J. Color Sci. Tech. 5 (2011), 137-144 © Institute for Color Science and Technology.

In this work, betacyanin food colorant were extracted from amaranthus by two different methods and purified with sephedex (LH20) and cellulose microcrystaline as solid phases. After extraction of colorant, spectrophotometric method was used for determination of extraction yield and quantification of colorant. Two extraction method was compared regarding to their content of the colorant and purity. High level colorant was observed in the methanolic extraction. But more colorant purity observed in acidic extracts. Applying the Sephadex column rised the purity to 3.6% for acidic and 8% for methanolic extraction. Final pure colorant was characterized by various spectroscopic techniques and high performance liquid chromatography.

Advanced Oxidation Processes (AOPs) are the effective processes in treatment of the various wastewaters contaminated with hazardous organic pollutants. In this work, decolorization of Acid Blue 74 in the UV/H2O2 process by using a batch photochemical reactor equipped with a 15 W low pressure mercury lamp (Osram) and aeration system as stirrer was studied. At the short time decolorization was complete and follows first order kinetic with respect of dye concentration. The rate of decolorization at the maximum absorption wavelength was monitored with spectrophotometric analysis. Effect of the important parameters such as initial concentration of H2O2, pH and initial concentration of dye on the dye decolorization was studied. It was found that the rate of decolorization increase with increase in H2O2 concentration up to 0.0294 mole.L-¹. The great rate of decolorization observed at the pH=3. With increasing the initial concentration of the dye up to 6.43×10-5 M, initial reaction rate was increased.