Chromic materials

Chromic materials is a term used increasingly to refer to dyes and pigments that exhibit a distinct colour change induced by an external 

Specific colour change phenomena are named using the suffix chromism and a prefix that describes the stimulus causing the change. Table 1 provides a list of phenomena and the stimulus involved, lonochromism, thermochromism, photochromism, and electro-chromism are the most extensively studied. The others listed are generally less well-established and have either experienced limited commercial exploitation or are essentially academic curiosities. Indeed, the list in the table is probably not exhaustive. 

Chromic materials are the general term referring to materials, which their eolor changes by the external stimulus. Due to color changing properties, chromic materials are also ealled chameleon materials. This eolor ehanging phenomenon is caused by the external stimulus and 

Solvatechromism is the phenomenon, where color changes when it makes contact with a liquid, for example, water. Materials that respond to water by changing color are also called hydrochromic and this kind of textile material can be used, e.g., for swimsuits. 

Comfort is very important in textiles because stresses lead to increased fatigue. The potential of smart textiles is to measure a number of body parameters such as skin temperature, humidity and conductivity and show the level of comfort through the textile sensors. To keep the comfort of textiles, adequate actuators are needed that can heat, cool, insulate, ventilate and regulate moisture. The use of the smart system should not require any additional effort. The weight of a smart textile system should not reduce operation time of the rescue worker. 

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The book is divided into seven chapters. Chapter 1 describes photo-chromic materials which have critical applications in memory technology. These compounds generally are activated by light. Chapter 2 covers leuco quinones which, in many cases, when oxidized, have their absorption maxima in the near-infrared region. Chapter 3 describes leuco dyes of a common group of compounds—oxazine, thiazine, and phenazines—that have found applications in color photography. Chapters 4-6 describe arylmethine-type compounds that can be triggered to dyes by common chemistry. Chapter 7 describes a special class of leuco dyes, namely, tetra-... 

Metal Complexes as Dyes for Optical Data Storage and Electro chromic Materials... 

The term chromic materials is a general one relating to materials that radiate, lose or change colour because of an induction caused by the external stimuli. Chromic is a suffix that means colour. Depending on the stimuli affecting the chromic materials, they can be classified as ... 

For use in write/read/erase memories various organic photo-chromic materials have been studied, and these are described in detail in Section IV. A wide variety of organic materials have been considered for use in permanent memories, all apparently involving some form of photoinduced polymerization, and these are described in Section V. While high sensitivity is desirable in these applications, it is less critical than in holographic interferometry, and in many cases it is not necessary that the material be sensitive in the visible spectral region. 

Dvornikov, A. S., Malkin, J., and Rentzepis, P. M. Spectroscopy and kinetics of photo-chromic materials for 3D optical memory devices. J. Phys. Chem. 1994, 98, 6746-6752. 

The sensing fibers explained in this section are based on the modified cladding structure [18-20]. The passive cladding of the optical fiber is removed from a small section and is replaced by a chemo-chromic material as shown in Fig. 11. The refractive index is a complex quantity given by... 

Electrochromism is the reversible change in optical properties of a material caused by redox reactions. The redox reactions can be initiated when the material is placed on the surface of an electrode. When the electro-chromic material is capable of showing several colors, it is addressed as polyelectrochromic. 

Carotenuto, G., LaPeruta, G., and Nicolais, L., Thermo-chromic materials based on polymer-embedded silver clusters. Sens. Actuators B, 114,1092-1095 (2006a). 

The first steps towards smart behaviour started off with the advent of Chromic Materials where textile fil es and fabrics were shown to display chairges in colour when subjected to differoit stimuli i.e. light, heat, electricity, pressure and liquids. Given their rather narrow spectrum of functionality, they initially attracted the fashion, design and the sport industries. However, currently much research is in progress trying to develop them into precision indicators and reactive technical devices that could be utilised in a wide range of medical and technical applications ... 

T Komatsu, Chromic materials Part I - Liquid-crystalline behaviour and electrochromism in bis(octakis-n-alkylphthalocyaninato) lutetium(III) complexes , J Matl Chem, 1994 4 533-536, DOI 10.1039/JM9940400533... 

Various other chromic materials are known, as listed in Table 1. Solvatochromism is an extensively-studied phenomenon whereby a dye... 

R. M. Christie, Chromic materials for technical textile applications, in Advances in the Dyeing and Finishing of Technical Textiles, ed. by M. L. Gulrajani, Woodhead Publishing, Oxford, UK, 2013. 

Chromism is the ability of a material to change its colour according to a stimulus. Chromic materials might also be called chameleonic materials , due to their ability to adapt to their environment [34]. The types of chromism are defined after the different stimuli that cause their change, such as ... 

Talvenmaa P. Introduction to chromic materials. In Intelligent textiles and clothing. Woodhead Puhhshing 2006. 

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