فهرست مطالب

  • سال هشتم شماره 1 (پیاپی 27، بهار 1393)
  • تاریخ انتشار: 1393/03/28
  • تعداد عناوین: 8
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  • M. Parvinzadeh Gashti*, Sh. Eslami, A. Almasian Page 1
    In this research, nano-iron oxide was synthesized on the surface and between clay layers using sodium carbonate and iron nitrate after thermal oxidation in 400 ° C. X-ray diffraction from synthesized pigment showed the presence of nano-iron oxide II crystals on the surface of the pigment. Moreover, thermal measurement of nano-iron oxide-clay pigment showed an improvement of thermal stability in comparison with clay. SEM and EDX results showed the presence of chemical elements of Fe, Al and Si on the surface of clay. Reflectance properties of nano-iron oxide-clay pigment showed that the intensity of reflectance in visible region and lightness value of pigment is decreased which is due to deposition of iron oxide nano-particle in the final pigment compound. Results from electromagnetic test showed an increased electromagnetic absorbance in clay/nanoiron oxide pigment in comparison with clay. J. Color Sci. Tech. 8(2014), 1-11©. Institute for Color Science and Technology.
    Keywords: Iron particles on clay, Thermal oxidation, Reflectance spectrophotometer, Electromagnetic waves instrument
  • L. Fathyunes, M. Azadbeh* Page 13
    In this study, the effect of different surface activation methods on characteristics of phosphate coating, such as morphology and paint adhesion quality, was investigated. The SEM micrographs showed that, surface activation by sandblasting, leads to formation of fine-grained and more compact coating including phosphate crystallites with the average length of 57.65 μm due to increasing the active centers for nucleation. While, the phosphate crystallites size of formed coating on the shot blasted or grinded surface were with the average length of 169.72 μm and 118.14 μm, respectively. Also, the SEM investigations showed that by using rephosphating as an innovative method, further reduction in the phosphate crystallites size to about 24.99 μm was obtained. EDX analysis and further SEM investigation confirmed that the formation of such coating could be in consequence of dissolution of base metal during first stage coverage and entrapping the small debris of initial phosphate layer in these regions, which can be act as nucleation sites during rephosphating. However, paint adhesion increases using phosphate coating, significant improving in adhesion was obtained with applying dense phosphate layer. On the other hand, by formation of denser coating with improved protective properties, the quality of wet adhesion of paint increases. J. Color Sci. Tech. 8 2014), 13-25©. Institute for Color Science and Technology.
    Keywords: Mechanical activation, Rephosphating, Fine grain, compact structure, Quality of paint adhesion
  • A. H. Karimy*, Gh. Vatankhah Page 27
    One of important aspects in the field of Art technology and conservation of Persian historical paintings is the characterization of binder (or binding medium) used in paints. The basic rule in this field is identification of historic materials without destruction of the works or the sample taken from them. ATR-FTIR (attenuated total reflectance-FTIR) is one of the common non destructive methods for characterizing organic materials in paintings. In this paper samples prepared using common binders of Persian paintings, have been tested for the evaluation of ATR-FTIR method. In the second step real historic samples have been tested. Results showed that the method is efficient in classification of binders (to hydrocarbon, protein and drying oil groups), but is not perfectly successful in detailed identification. Detailed research needs other test methods. J. Color Sci. Tech. 8(2014), 27-36©. Institute for Color Science and Technology.
    Keywords: Binder, Persian painting, Proteins, Drying oils, ATR, FTIR
  • F. Talebnia, F. Nourmohammadian*, S. Bastani Page 37
    In this research, disperse yellow 232 was synthesized, purified and subjected to spectroradiometric study in different resin media. Alkyd, maleic and phenolic resins as common useful resins in offset printing inks were applied to study the effects of different media on fluorescent emission of the dye. Reflectance curves in two UV-cut and UV-add statuses were measured under A light source. The emissions in the different media were calculated in two different ways. First, calculation of emission intensities differences in UV-cut and UV-add reflection curves in maximum emission wavelength, and second, calculations of difference area between the two curves were measured, and the results were in good accordance. J. Color Sci. Tech. 8(2014), 37-46©. Institute for Color Science and Technology.
    Keywords: Coumarin, Fluorescent dye, Reflectance, Printing ink, Offset printing
  • H. Ahmadi Moghaddam* Page 47
    B2O3-PbO, La2O3, Nb2O5 base glasses have uses in electro-optics, special reflective glazes and semi-mirror glasses. The aim of utilising of these glass systems as glaze bases is to attain special optical properties, for example, ultra high refractive index and low dispersion. In this research, B2O3, as a strong glass-former, hosted great amounts of PbO, La2O3 and Nb2O5. They were mostly colourless, or had low colour shades. The challenge was to achieve ultra-high optical properties stable glasses. Thermal Differential Analysis, DTA, experiments were carried out to determinate the glass stability. From the stable glasses, accurate slabs, circular bars and prisms were prepared for measuring optical properties. High refractive index and light dispersion were measured by minimum angle of deviation in prism. Results indicated that the stable glasses were limted. The light dispersion was low i.e. Abbe No.>10, and the relative reflection was 8-14. J. Color Sci. Tech. 8(2014), 47-57©. Institute for Color Science and Technology.
    Keywords: Glaze base, High refractive index, glazes, Heavy element oxides, Stable glassy structures
  • N. Tahmassebi*, R. Marashi Page 59
    In this study, the influences of thickness on the weathering performance of coating systems including zinc rich epoxy or ethyl silicate primer, epoxy/polyamide surfacer and polyurethane topcoat were investigated. Natural weathering was evaluated in Arak in center of Iran and Mahshahr located near Persian Gulf. The results showed that gloss retention of the systems exposed to Arak was higher and there was a relatively low variation in yellowness index of the systems that can be attributed to gradual surface erosion. Surface erosion, postcuring and photodegradation of the topcoat also caused a fluctuating variation in hardness of the systems. In addition, the results presented that 800 hours accelerated weathering was equal to 7 months natural weathering in Mahshahr. It was also found that an increase in thickness increased cyclic corrosion resistance of the epoxy systems, while, no defects were detected on surface of all the systems during salt spray and natural weathering. J. Color Sci. Tech. 8(2014), 59-74©. Institute for Color Science and Technology.
    Keywords: Zinc rich epoxy, Zinc ethyl silicate, Natural weathering, Accelerated weathering, Salt spray, Cyclic corrosion
  • Fahime Razavi, Mahdi Ghahari*, Majid Rashidi, Huyeh Page 75
    Lustre production technique is one of the oldest methods of metal nanoparticles fabrication depended on chemical reducing atomosphere. This kind of ceramics is consisted of three steps; body production, applying white glaze on a body and after baking, recovering the lustre glaze on the opaque white glaze. Lustre has fascinating features due to the formation of a thin layer and metal nanoparticles. In this situation, the sample appears in different colors by changing the incident light angle. This happens due to the nano structures created during the manufacturing of the glaze. In this research, a new combination of lustre glaze was produced which is suitable for Arcopal body. Therefore, numbers of thermal treatment steps were reduced from 3 steps to one step. SEM analysis was used to identify the thickness of the thin layer. The layer varies between 200 to 400 nm. The theoretical studies and stimulation of the reflection spectra at different angles show that these results have good agreements with the experimental ones. J. Color Sci. Tech. 8(2014), 75-83©. Institute for Color Science and Technology.
    Keywords: lustre, Silver nanoparticles, Arcopal
  • F. Mahyar*, H. Izadan, L. Taghavi, S. Sadeghian Nodoushan Page 85
    Due to the lack of consistency in defining colour harmony by different people, the present research was focused on finding the meaning of colour harmony. The relationships between colour harmony and colour pleasantness, beauty, calmness, and hue contrast were examined in order to fascinate the selections of the most harmonious colour combinations in different applications. A psychophysical experiment carried out for two colour combinations. On the basis of a novel method of data analysis, the results show that the term of colour harmony is not the same as any of the inspected colour terms. However, the meaning of colour harmony is much closer to the meaning of the colour beauty and the colour calmness. The concepts of colour beauty and colour pleasantness are also similar to each other. Furthermore, it seems that the male observers have a less tendency in selecting the complementary colour harmony pairs than the female observers. J. Color Sci. Tech. 8 2014), 85-92©. Institute for Color Science and Technology.
    Keywords: Colour harmony, Colour beauty, Colour pleasantness, Colour calmness, Hue contrast