نشریه مطالعات در دنیای رنگ
سال سیزدهم شماره 2 (پیاپی 49، تابستان 1402)

The water-resistant polymer coating has attracted much attention due to its low toxicity, low volatile organic compounds, and outstanding chemical resistance. Despite these advantages, the microporous defects and polar channels that are formed during the curing process lead to O2</sub>, H2</sub>O, and Cl</em>-</sup></em> being sent to the metal substrates and cause blistering of the coating and loss of adhesion in the coatings, and as a result, the properties of the barrier coating are reduced. Participating nanofillers in a polymer resin to reduce coating defects is an effective method. Epoxy matrices with layered nano-plates as reinforcement have recently attracted significant attention in scientific research and practical applications due to their excellent mechanical performance, barrier against gas factors, and thermal conductivity. In general, enhanced barrier function in corrosive environments provides excellent corrosion prevention. In this regard, in this article, the effects of graphene oxide nanosheets, graphene, graphite fluoride, carbon nitride, boron nitride, boron carbonitride, LDHs, and Mxene are investigated.</em>

Many studies have been conducted on the synthesis, properties, and application of core-shell polymeric nanostructures. In this review, organic-organic and organic-inorganic core-shell structures, along with their synthesis techniques, have been investigated. The processes of making these structures include multi-stage seeded polymerization (including emulsion, miniemulsion, Microemulsion, Pickering emulsion, etc.), co-precipitation, and sol-gel. Among them, the emulsion polymerization strategies are the most paramount. Core-shell polymers are hybrid composite particles that have at least two different components. There are also parameters such as the kind and quantity of initiators, glass transition temperature (Tg</sub>), and crosslinks Density (CLD), which affect the morphology of particles. Soft or stiff core or shell, glass transition temperature, type of inorganic nanoparticles, and nanoparticle modifier can lead to different efficiencies for this type of core-shell polymer structure.

In recent years, perovskite solar cells have attracted attention due to their increased power conversion efficiency, simple manufacturing process, low-cost materials, and unique properties such as band tunability, high electron and hole mobility, and low exciton binding energy. Also, the efficiency of perovskite solar cells has exceeded 25 % due to the high quality of perovskite film, synthesis methods, coating, and appropriate electrode materials. This article examines the recent progress of perovskite solar cells, structure, and types of coating methods to understand better and gain complete insight into perovskite solar cells. In the following, some types of perovskites, holes, and electron transfer layers are compared, and their effect on solar cell efficiency is reported. Finally, the types of perovskite coating methods with large and small areas are discussed, and the challenges and opportunities of perovskite solar cell commercialization are suggested.

Thermochromic or thermochromic materials change color reversibly with an external stimulus, i.e. temperature. It is used to change color in a certain environmental range to prepare smart textiles. A variety of thermochromic materials are available, which can be classified into direct and indirect. Thermochromic materials change color in a subtle and reversible way with increasing and decreasing temperature and can change from colored to colorless or vice versa or from one color to another. These materials can be combined with ordinary colors and get newer colors. Thermochromic dyes cannot be used on direct textiles due to the surrounding environment and low reactivity. They are usually used in the form of microcapsules. Thermochromic materials are used to produce smart textiles through dyeing or printing. These textiles are used in various fields such as wearable displays, sensors, insulation materials, anti-counterfeiting materials, and military industries. Textiles printed with thermochromic microcapsules have good stability properties but are very sensitive to light, solvents, and high temperatures.

It is no secret that color is one of the most important visual elements in art, culture, and marketing. Color is the fastest way to convey messages and meanings among the different types of non-verbal communication. Due to the way colors stimulate or activate the senses, colors can have other psychological and emotional effects on people. The science of color therapy is also used to improve and correct mental patients' moods since color affects their mental health. According to this article, Pantone company has chosen blue as its clothing and interior decoration color in different years. The psychology of Max Loescher shows that people choose colors based on sensory reactions, and this research shows that the most popular color in the world is blue.  

Pictographs of Lorestan province in Kuhdasht city are one of central Zagros' most prominent and important cultural works. The paintings of this region have not been studied from an experimental point of view. Considering the use of colors and their importance in Iranian art, these colors were sampled in a tiny amount, considering the principle of no visual damage. To achieve the research goal, laboratory methods have been used to identify the color substrate and pigments. In this research, three pigments, red, black, and orange, have been investigated by petrographic and FT-IR methods. In the method of thin section petrography and device analysis with James Swift model polarizing microscope, aiming to determine the bed and type of rock, Fourier transform infrared spectrometer (FT-IR) was used to identify the type of pigment. The archeological investigations on the colored pieces show that the type of pigments used to make the motifs were completely mineral, and no organic pigments were found. Microscopic images of the sections of the paint layer show that these pigments were applied directly on the rock, and as a result, there was no substrate. Therefore, the pigments used to draw motifs are a mineral structure and a combination of iron; where the natural red pigment of the earth, depending on the iron oxide chromophores and the presence of other minerals, can create orange tones to red and black shades, which can be seen as increasing or decreasing the type of iron oxide. Finally, considering that the structure of the colors was in the form of mineral compounds, it can be acknowledged that this structure is one of the most important reasons for their durability.