نشریه مطالعات در دنیای رنگ
سال هشتم شماره 1 (پیاپی 28، بهار 1397)

The current report aims at reviewing the all coating-based methods to protect the cultural heritage assets. At first, the necessity of protection for cultural heritage assets is proposed. Then, all types of cultural heritage objects including textiles, papers, metals, leathers and … are introduced. Finally, general protection procedures are proposed. The main characteristics and requirements which have to be used in coating of cultural heritage objects are explained. Among various coating systems, Acrylic, Fluorinated resins, silanes, hybrid coatings are introduced that can be good candidates for cultural heritage protections against various harsh environments. In addition different functional coatings (like self-cleaning, weathering resistant, anti-bacterial, …) are proposed for cultural heritage protection purposes.

Different types of pollutants contaminated waste paper and various methods are used for removing these compounds. One of the most important of these pollutants is printing ink. Deinking of waste paper is done in different ways and also the research on new methods is ongoing. Among various printing techniques, electrophotography technique (LaserJet printers and photocopiers) because of the toner mixing with paper tissue during the fixation process which is combined with high temperatures the traditional deinking methods are nor useful. Therefore, research are and are necessary to use newer. Deinking method for papers printed by electrophotography methods is done by using enzymes, alkaline process, free radicals, radiation, UV, ultrasound. The purpose of this article is to explain the methods and also their efficacy is comparable.

One of the most common approache for protection of metals against corrosion is application of organic coatings. These coatings provide physical barrier against diffusion of water and ions to the metal surface. However, environmental issues such as UV irradiation, thermal and mechanical stresses (scratch and crack) are responsible for the coating damage, resulting in the creation of pores and defects in the coating matrix. Therefore, active corrosion inhibition and barrier protection action are required for metal protection against corrosion. One method for achieving an active corrosion inhibition effect is the use of inhibitive anti-corrosive pigments. Chromate is one of the most popular inhibitive pigments. Howevre, its use in organic coatings has been strongly restricted due to its toxic and carcinogenic nature. The organic/inorganic pigments can be categorized into barrier, sacrificial and active inhibitive pigments. Direct loading of corrosion inhibitors into the coating results in undesirable and negative effects on its curing and structural properties. One effective strategy for overcoming this issue is encapsulation of corrosion inhibitors into the micro-nano containers. In this study different methods for encapsulation of corrosion inhibitors and their inhibitive mechanisms are reviewed and discussed.

Eliminating and preventing the spread of microbes from the past has been considered. Antimicrobial coatings are one of the ways to fight pathogens. Acrylic and methacrylic resins, cationic conjugated polyelectrolytes, siloxane resins, hyperbranched resin, tetrachloride resins, resins with quaternary ammonium end group, heterogeneous resins with nitrogen, guanidine-containing resins, natural mimic peptides resins, synthetic peptides, resins with main chain of arylamide and phenylethylene, halogenated resins containing phosphorus and sulfur derivatives, phenol and benzoic acid derivatives resins, and organometallics compounds are the materials studied. Also, to create antimicrobial activity in them, other operations such as covalent integration of low molecular weight antimicrobial compounds, antimicrobial peptide binding, grafting other antimicrobial resins, addition of low molecular weight antimicrobial compounds, alloying with antimicrobial resins, and addition of antimicrobial inorganic compounds to resins by different researchers has taken place. In this article, examples of these studies are briefly presented.

Forgery occurs when a person deliberately deceiving individuals or legal entities by changing something. Although the forging has old history, it has increased a lot in the twentieth century with the progression of applied science. Among various types of forgery, our goal is to review documents forgery. In the document forgery, three cases may happen: 1. Forgery by obliteration 2. Forgery by adding text 3. Sequence of intersecting lines. Consciousness of each of these three items and ability to identify each one is mandatory to prevent possible abuses. One of the issues involved in document forgery in the judicial industry is sequencing of intersecting lines. Thus far the methods given in this study have many problems that declare more research is needed to engage in real events. The purpose of this article is to understand the types of forgery and some methods for detecting forged documents.

Today, due to the concerns about the importance of environmental issues, the tendency of applying of natural dyes for dyeing the textile materials has been increased. In this regard, it is preferred to apply the natural additives instead of synthetic materials for pre-, meta- and post treatment processes. As instance, the use of herbal mordant instead of those of mineral or metal for dyeing process of natural fibers has been extremely attracted attentions. However, replacement of metal mordant by the herbal ones will influence both the colorimetric attributes as well as the color fastness of the final product. In this report, the basic concepts and studies related to definition of colorimetric attributes of natural dyes employed for cotton, woolen and silk textiles have been considered, firstly. Then, the effect of applying of natural dyes on different fastness properties, i.e., light fastness, wash fastness, wet and dry rubbing fastness have been reviewed.