نشریه مطالعات در دنیای رنگ
سال هفتم شماره 1 (پیاپی 24، بهار 1396)

In this paper, a review on the synthesis methods of carbon hollow micro/nano structures according to the recent literatures is presented. At first, the kinds of hollow structures will be mentioned and then, the synthesis methods of carbon hollow spheres (CHS) including chlorination of metallcarbides, hard templating, soft templating and self templating will be discussed. Two first methods are widely used for synthesis of CHS. Hereby, in the first step, basic concepts of the methods and then, kinds of templates used in synthesis of CHS and the related publications will be considered. Soft and self templating methods are the most important ways for synthesis of hollow structures based on polymer, metal oxides and silica materials. These methods are not appropriate for the synthesis of CHS due to hydrothermal and carbonization processes at high temperature. Consequently, these methods will be briefly described.

Many types of colorants obtained from plants, animals and microbes sources have been investigated for their usage in different kinds of application. Much research into new natural colorants sources along with low cost and eco-friendly are in progress for their varied production and application in different domains. This paper present recent research performed in the area of application of natural colorants, with specific emphasis to technological development in natural textile and fabrics dyeing, food colorants and dye-sensitized solar cells. Finally, some newly discovered applications of natural colorants have been presented.

Doping corrosion inhibitor in a host structure (container) draws much attention among the researchers. This system, called smart corrosion inhibition, is designed not only to avoid undesirable reactions between the corrosion inhibitor and the matrix but also letting the inhibitor to be consumed just where it is needed. Moreover, in some cases, this system can undergo self-healing properties, if the coating is scratched. A lot of strategies are suggested to achieve these purposes, including loading corrosion inhibitor in nano-micro capsules, doping corrosion inhibitor in porous containers and etc. Other reservoirs that can be loaded with corrosion inhibitor are nanotubes, ion exchange particles, conductive materials, layer by layer polyelectrolytes, and porous materials. For instance, multi-layer polyelectrolytes can be used to immobilize the corrosion inhibitor. Changing the system conditions can cause polyelectrolytes to weaken, and letting the corrosion inhibitor release. In general, an ion exchange occurs between corrosive ions and inhibitor's in the system, or the inhibitor is released due to local pH changes, or as a long-term diffusion, the inhibitor can avoid corrosion reaction. Therefore, some changes are needed in the system to commence smart corrosion inhibition process.

Carpet is an instance of Islamic art and a display of beauty and religion. This national art became the center of focus during the reign of the Safavid dynasty. Many carpets with different designs and patterns have survived from this era, each carrying a particular meaning with the aim of promoting Shia Islam. These include prayer carpets and rugs which were produced in many sizes and variants in court workshops. These carpets and rugs gained importance in this era due to their religious applications. Prayer rugs which have affinity with the architecture and structure of mosque sanctuaries, have decorations of plant colors, geometric abstract arrays, and pictographs which contain content from Hadith and the Quran. With regards to symbolism in Persian carpet and religious application of prayer carpets, first, the colors of Safavid prayer carpets have been studied in this paper in order to identify the common colors used in these carpets. Next, the color of prayer carpets have been compared to other types of carpets in order to specify whether the use of these colors were deliberate or accidental. Results show that these colors were knowingly chosen and have differences with colors in non-prayer carpets. Although many patterns are used in prayer carpets, only seven specific colors have been applied. These colors, which are considered sacred and respected in Islamic mysticism, are white, black, brown, blue, red, yellow, and green. Each of these colors are constantly utilized in general prayer carpets and portray symbolic and sacred meanings such as promoting Shia Islam, unity, and the presence of man in heaven. Thus, it can be concluded that the role and composition of colors in Safavid prayer carpets is based on implied meanings, which in addition to introducing Islamic and Shia concepts, increases the spiritual state of worshipers in their prayers. This research has been conducted with library sources, and descriptive and analytic qualitative method.

The most important challenges in color technology with that researchers and industries are faced, is description, consistency and control of color appearance while is supposed to be transferred between different reproduction devices. In this article, the concept of color management for color reproduction of digital images as a suggested solution has been reviewed in brief to achieve a color consistency of an image during workflow from the design step to the publishing step. Color management system makes it possible to keep the color appearance of image consistent between different devices. This is possible if dependent-device color values could be converted to independent-device ones through an intermediate color space. Moreover, the image color management workflow, the conventional methods and the related standards with that have been pointed, too.

Hair color is one of the oldest cosmetics known by many ancient cultures in different parts of the world like the ancient Egyptians, Greeks, Persians, Chinese and Hindus have been used. Before the advent of chemical colors, creative use of natural products for hair color, was common. Natural colors, including colors with plant source (henna, beet, madder, chamomile), animal origin (Cochineal insects, species of mussels) and metal salts. As well as chemical dye the hair into three categories: temporary (non-oxidizing), semi-permanent colors (non-oxidizing) and permanent colors (antioxidant) are divided. In general, chemical hair colors is divided into two main categories oxidant and non-oxidant. And the durability of color into three categories: temporary, semi-permanent and permanent split. In this article, we will describe the types of hair color and structure and characteristics of each are discussed