نشریه علوم و فناوری رنگ
سال دهم شماره 3 (پیاپی 37، پاییز 1395)

The decolorization conditions of aqueous solutions containing basic red 13 with sonoelectrochemistry system by titanium dioxide nanoparticles using central composite design was optimized. The effect of different parameters affecting on decolorization process, including time, the amount of TiO2 nanoparticles, initial pH and the applied potential was investigated. Based on the results, lowest amount of color removal at pH = 5.0 and the highest amount of decolorization in moderate alkaline environment (pH=8) has been achieved. Decolorization was increased by increment the amount of titanium dioxide nanoparticles to 0.68 g/l and then slightly decreases. By increasing the applied potential up to 0.85 V, the Decolorization increases with mild slope and then remains constant. The time of sonoelectrochemistry process has a direct effect on decolorization.The analysis of variance (ANOVA) showed that the main influencing factor was the pH and amount of TiO2 nanoparticles, the time and amount of applied potential followed in order to be effective. The optimum conditions for the degradation of dye were found to be as follows: pH= 8, time = 91 min, applied voltage = 0.85 V and nano TiO2 amount = 0.685 g/l. The present results showed that sonoelectrochemistry assisted by TiO2 nanoparticles have a good potential for dye removal from aqueous solution in the industrial application.

In this study, spherical-like polypyrrole nanoparticles with diameter smaller than 100 nm were synthesized via emulsion polymerization using FeCl3 as dopant and initiator simultaneously. Chemical structure of polypyrrole was confirmed with FTIR spectra. Furthermore, the morphology and the size of polypyrrole nanoparticles were investigated by SEM images. The structural order of samples was investigated using XRD analysis and the conductivity of samples was measured by four point probe method. In this work, effective factors on the conductivity of resulted polypyrrole including reaction temperature, initiator concentration and feeding strategy were investigated. In this study, without the use of complex equipment of synthesis or the use of different raw materials simply by optimizing the reaction conditions, a product with a conductivity of 8.5 S/cm was obtained. Moreover the aging effect on the conductivity of product was discussed.

The color phenomenon is one of the subjects and matters that has remained as a secret among some of philosophers and scientists and has not been still presented an acceptable theory to explain all the questions and issues of the color.In contemporary times, the epistemology has acquired a great importance in every matters, so the philosophers and some other scientists - specially the western scientists- take the color phenomenon with the epistemological methods into account.Maybe it Will be possible to contemplate and investigate all the epistemological questions about the subject of color, but investigating these kinds of epistemological questions requires the precise basis in the relation of some solids with the color and also knowing the color.It seems that it is impossible to answer the epistemological questions about color without considering those relations.This research would assert to at least five great important subjects as, "solid(body)"," light "," sight system ", " brain", "mind" and their relation in knowing the color as the first step.

The presence of nanoparticles in the polymer matrix will cause an increase in the mechanical performance of nano-composite. In this research the nature of reinforcing material was investigated by mixing pure polyurethane with two different nanoparticles, silicon carbide or alumina. The composition was selected in three levels; 1, 2.5 and 5 in weight percent. The dispersion and distribution of nanoparticles were examined by scanning electron microscopy (SEM). Adhesion, abrasion and hardness tests were applied to study the physical properties of the coated layers. The results were confirmed that in case of silicon carbide by increasing the amount of additive to 5%, all the adhesion, abrasion and hardness values reduced. While by substituting alumina with silicon carbide this trend has been changed to a positive value. Polyurethane-5% Alumina nanoparticles shows 25% increase in adhesion, 23% increase in abrasion and the hardness increases from 3H to 5H.

Azo dyes are a group of hardly degradable dyes characterized by existence of azo group in their structure. The purpose of present study is the isolation of capable fungi for azo dyes biosorption. Fungi strains isolation was performed by enrichment method. The ability of selected fungal isolate in bio-decolorization was examined using different concentrations of dye. The best dye removal with a rate of 90% at concentration of 1000 mg/l was achieved after 5 days. This fungal isolate is capable to grow in 100 g/L NaCl. Molecular identification revealed 99% similarity to Neosartorya fischeri. Investigation of dye desorption showed that acetone is the best solvent for desorption. It is worth mentioning that, this strain has high ability for biosorption of dyes from textile wastewater. To our knowledge, this is the first report regarding the biosorption potential of Neosartorya sp., and it can be a potent biological agent for treatment of textile effluent.

In this research the effect of appearance factors of automotive finishes on their blackness perception is investigated under various types of illumination. In order to decrease the effect of colorimetric attributes on perceived blackness of panels, samples with nearly identical colorimetric properties, i.e., lightness, chroma and hue, are selected. Regarding the industrial and commercial approach of the subject, the selected panels benefit from the optimum geometric appearance factors (higher values of distinctness of image and gloss as well as lower orange peel values) which are preferred by the majority of luxury vehicles customers. The pair comparison method was used to visually rank the blackness perception of metallic black panels. Results showed that there is not any significant relationship between the geometric appearance factors of automotive finishes and their blackness perception under different types of illumination, i.e., light booth, diffuse illumination and the unidirectional illumination.

In this study, kinetic behavior and dyeability of woolen yarns with madder and cochineal natural dyes were investigated. Dyeing rate was separately calculated for each dye at different times and temperatures. Results showed Patterson’s rate equation as the best model to describe dyeing rate in which rate constants in the range of 0.0031-0.0341 and 0.0024-0.0318 were obtained for cochineal and madder, respectively. Dyeing temperature had essential role on kinetic behavior and with the increase of temperature, dyeing rate and equilibrium time increased. Cochineal demonstrated better dyeability on wool than madder. Saturation point on wool was achieved using 20% and 60% owf of cochineal and madder dyes, respectively. Diffusion coefficient values at different temperatures were calculated from Hills’ equation, and it was found that temperature had key role on diffusion values. As temperature raised from 30 to 95 °C, diffusion coefficients increased from 0.83×10-11 to 7.4×10-11 in the case of madder and from 1.02×10-11 to 11.32×10-11 in the case of cochineal dye. Overall, the results of this study confirmed better dyeing performance, higher rate constant and diffusion coefficient for cochineal on wool compared to madder.