نشریه علوم و فناوری رنگ
سال دهم شماره 2 (پیاپی 36، تابستان 1395)

Luster glaze is a very thin layer of silver and copper nanoparticles with a metallic luster in different color range formed on the surface of the glaze during the third stage of heating in reduction condition. Javaher name-ye-Nezami by Mohammad- ibn Abi-al-BarakatJuhari-Nishaboori is the earliest historical documents on Luster glaze which has various formulas for making this glaze.However, the key question is, whether one can still produce luster glaze based on these formulas. In the present study, by using an experimental approach, we verify the accuracy of one the formulas presented in this book. The first formula in the book Javaher Name-ye-Nezami was chosen while the research method was evaluative and it has been done through observations and experiments. The results show that the formula presented in Javaher-Name-ye-Nezami are quite capable of preparing Luster glaze.

This study was designed to investigate the effect of nano silica particles on the pressure-sensitive acrylic adhesive bonding on polypropylene film. In this work, the effect of plasma treatment on polypropylene films was examined. Selected variables including plasma treatment time, power and gas type at three levels were considered. Results were analyzed by Taguchi method and optimum condition of high adhesive strength at 7 minutes, power of 100 W and argon gas was obtained. Then varying amounts of silica nanoparticles were added to the acrylic adhesive. Adhesion strength test method was evaluated and the results showed that the strength increases to maximum value at 5.0 weight of nano silica. Functional groups on PP surface following plasma treatment were also detected using ATR- FTIR method; moreover, the etching condition of the surface was examined by both SEM and AFM methods.

In this study, woolen pile used in hand-knotted carpet was modified through biocompatible chitosan derivative, namely, chitosan- polypropylene imine dendrimer (CS-PPI) hybrid, and then its dyeability and color fastness using weld natural dye were investigated. The impact of CS-PPI, dyeing pH and dye concentration on the dyeability of the substrates were then studied. According to the results, as the CS-PPI amount increased, the dyeability and color depth was considerably enhanced. In the case of modified wool, the amount of dye exhausted at pH 7 was markedly higher than that at pH 4 while no appreciable difference was observed for pristine wool dyeability with pH changes. Color strength (K/S) data were in the following order of the CS-PPI modified wool>Aluminium-mordanted wool>pristine wool. Modification of wool had no adverse impact on color fastness and even in some cases resulted in minor improvement in fastness properties. Overall, it was concluded that mordant and acid could be eliminated from natural dyeing through wool modification with biocompatible CS-PPI that is of great importance from ecological point of view.

In this study, decoloration of reactive dyes with different structures has been discussed by using Multiwalled Carbon Nanotubes (MWCNTs) and hydrogen peroxide under UV radiation. Adsorption rate was investigated under various parameters (initial dye concentration, salt and pH). The dye removal results has been significantly decreased by increasing of dye concentration with the optimal value of carbon nanotubes (0.2 g/l) and pH=4. Also, by raising the salt dosage, the dye removal is gradually reduced. The COD removal results indicated that the hydrogen peroxide under UV radiation causes degradation color and producing pollutant. The results of coefficient constant R2 showed that the dye adsorption of this reactive dyes were correlated reasonably well by Langmuir isotherm. Moreover, the kinetic of this dyes according to their coefficient constant followed the second-order pseudo model.

Colors are the most widely consumed chemicals in different industries which always some colors enter in nature. The destruction and removal of organic pollutants in ways that are not harmful to the environment are important. Organic pollutants can be removed by many compounds such as photocatalys that porphyrin is one of the most important of them. In this study, removal of color pollutants has been investigated from environmental samples by magnetic nanoparticles functionalized with porphyrin. Firstly, magnetic nanoparticles synthesized and functionalized by the NH2 groups, then porphyrin photocatalyst had been placed on the particles. FT-IR spectroscopy and transmission electron microscopy were used for identification of strucrure and size of synthesized nano particles. After a three-step synthesis, under optimal conditions (temperature 20 °C, adsorbent 20 mg, absorption time 5 minutes and maximum capacity 76 mg g-1) remove of pigments was determined by this nanoparticles. Under these optimum conditions, group of colors that can be used as an indicator and also water-base colors were tested.

CdTe quantum dot was synthesized by a wet chemical route in aqueous solutions, and used as a visible-light responsive photocatalyst for the photodegradation of pollution dyes. The Quantum Dots (QDs) size was controlled by adding TGA as a capping agent. The structure and properties of CdTe quantom dot were characteized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Photoluminescence (PL) and UV-Vis. The average size of CdTe quantum dot was found to be 2.8 nm. In this study, a cationic dye (i.e. Thionine) was chosen as a model molecule to investigate catalytic behavior of the prepared CdTe QDs as efficient nano-materials. The effect of dosage of QDs, pH, time and initial dye concentration on the degradation effeciency of dyes were studied. The possible mechanism of visible light photocatalytic degradation is also proposed.

ZnTe Quantum dots (QDs) were successfully synthesized via co-precipitation method in an aqueous medium by using sodium tellurite (Na2TeO3) as the tellurium precursor, for the first time. Using sodium tellurite caused avoiding the complicate processes associated with the preparation of NaHTe and H2Te precursor materials and facilitated the synthesis process. Phase and microstructure of the obtained QDs were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) methods, and their optical properties were studied by UV-Vis absorption and photoluminescence spectroscopy measurements. XRD analyses revealed formation of single phase wurtzite ZnTe nanocrystals. The average nanocrystallite size was estimated by the Williamson–Hall method, came out to be ~ 2 nm. Optical band gap of the produced QDs was determined through fitting the measured optical absorption spectra, which confirmed quantum confinement effects. The average size of nanocrystals was calculated based on the optical data, using the Brus equation, to be 2.1 nm, which is close to the Williamson-Hall calculations. TEM micrographs indicated that ZnTe QDs with rather spherical shape and uniform morphology are obtained.