JOURNAL OF COLOR SCIENCE AND TECHNOLOGY
Year:2011 | Volume:4 | Issue:4|Papers Count:8

Adsorption of a basic dye-methyl violet (MV) on bentonite clay, CuFe2O4 and /bentonite CuFe2O4 in aqueous solutions was investigated. The composite of Cu and Fe and bentonite by co-precipitation method at pH=11 was prepared. The prepared composite can be used for dye removal, and then separated. XRD result showed spinel structure for CuFe2O4. SEM image showed the particles size is about 50 nm for CuFe2O4. Effect of experimental parameters such as pH, contact time of sorbent and dye, mass of sorbent and temperature on MV removal were investigated. Maximum dye removal at pH=12 and contact time 15 min was observed. In abscence of Cu ferrite contact time of bentonite sorbent increased to 60 min. In the presence of Cu ferrite a very high rate of dye removal was observed.

It is now recognized that adsorption using low-cost adsorbents is an effective and economic method for water decontamination.Chitosan is derived by deacetylation of the naturally occurring biopolymer chitin which is the second most abundant polysaccharide in the world after cellulose. In this paper removal of two anionic dyes from textile effluent in both singular and binary systems is investigated. Direct Blue 78 and Acid Black 26 was used as anionic dye models. The surface characteristics of chitosan were investigated using Fourier transform infra-red spectroscopy and scanning electron microscopy. The influence of process variables such as adsorbent dosage and pH were studied. Results indicate that chitosan could be used as a biosorbent to remove the anionic dyes from contaminated watercourses in both singular and binary pollutants systems.

In this study, the effect of an adhesion promoter was investigated on the adhesion of an epoxy silicone coating. N-2 amino ethyl- 3 amino propyl-3 methoxy silane was used as an adhesion promoter and was incorporated into the epoxy clear coat. The effect of the additive, using a sol-gel process on the final properties of the coating was investigated by adhesion, hardness (Vickers) and tensile measurements and DMTA analysis. The results indicated an increase in the coating adhesion in the presence of amino silane as compared to that of epoxy silicone resin. This is due to the formation of chemical bridges as a result of covalent bonding between silanols and hydroxyls at the surface. On the other hand, the formation of a three-dimensional siloxane network in the condensation process of silanols resulted in a higher crosslink density of the system and a denser network. The results showed that the use of amino silane compounds in epoxy silicone coatings can be an effective way to increase the adhesion.

Curing of relatively thin polymers via radiation in various applications such as varnishes, paints and printing inks has recently developed. Urethane acrylate resins are among the most important radiation curable resins which can be used in different industries such as automotive industry. Since scratch resistance is very important in lots of these applications, improvement of scratch resistance of mentioned coatings via incorporation of nano particles attracts a lot of interest. This study is dedicated to investigation of the effect of nano alumina particles on physical and mechanical properties of UV curable urethane acrylate, especially scratch resistance. Scratch resistance of different coatings was evaluated by nano indentation microhardness and adhesion strength of coatings have also investigated. The results depicted that the scratch work increases from 470 to 700 pJ and the elastic modulus from 1.9 to 2.3 GPa. In general, results showed improvement of urethane acrylate coating properties via addition of nano alumina.

Sorption isotherms of three nonionic disperse dyes, Blue 3, Red 1 and Yellow 3 on nylon 6 fibers were studied at 90 and 98°C. A remarkable deviation from Nernst trend was obtained for all cases. Performance of Dual-Mode sorption model which is consisting of Langmuir mechanism for covering of initial curvature zone and Nernst model for the later nearly linear part was tested. Dual-Mode fitting was appeared to be in good agreement with experimental data. In addition, temperature effect on Dual-Model isotherm and on saturation point of fiber at two selected temperature was compared. The results showed the capacity of fiber for solution sorption is increased by increasing the temperature; however an important part of the total sorption was still followed as Langmuir isotherm.

Two novel monoazo acid dyes based on naphthalimide have been synthesized utilizing 4-amino-N-methyl (butyl) -1, 8- naphthalimide as the diazo components and J-acid as the coupling component. The 4-amino-N-alkyl (methyl/butyl) -1, 8- naphthalimides were diazotized with nitrosylsulphuric acid and afterwards they were coupled with J-acid. All obtained monoazo acid dyes were characterized using DSC, FTIR, 1HNMR and elemental analysis. In order to study and compare their dyeing properties and UV-visible spectroscopy, two monoazo acid dyes based on azobenzene have also been synthesized utilizing aniline and p-nitroaniline as the diazo components and J-acid as the coupling component. Spectrophtometric properties of the synthesized dyes were investigated in different solvents and their halochromic behaviors were considered. Finally, the polyamide and wool fibers were dyed by two monoazo acid dyes and then fastness properties were investigated. The data showed that all monoazo acid dyes have dyed fibers with good dyeing properties and all synthesized acid dyes have excellent wash fastness, good milling and perspiration fastness and poor light fastness.

In this research various compositions of (Pr, Zr) SiO4 were synthesized and the effect of praseodymium content and replacing Iranian rice husk with silica was investigated. The samples were calcined at 1050oC and then washed and milled. One of the interesting results of the research is that the variation in praseodymium oxide content, did not considerably alter the L*a*b* coordinates. As a result, it is possible to produce more economical pigments using less amount of this oxide. Furthermore, by substituting rice husk ash with silica the yellow component of the pigments decreased, which is probably owing to the impurities of the rice husk ash, which in this case may be removed by washing with acid. The XRD results showed the formation of ZrO2 and ZrSiO4 which regarding the yellowish color of the pigments, it may be concluded that praseodymium has entered the structure as solid solution.