Transparency and Color

Phenazine leuco dyes, like their thiazine and oxazine analogues, have also found application in electrolytic recording, overhead transparencies, and Color Dry Silver. The phenazine leuco 48 is employed in electrolytic recording,17 whereas compounds 49, 50 are described as useful in thermographic and photothermographic systems.18... 

Nacreous pigments require transparent or at least translucent binders or other carriers. Formulations with other pigments have to take their transparency and color mixing rules into account. Producers specify certain product lines for specific applications on the basis of national regulations and technical considerations. They also provide handling guidelines and starting formulas. 

Preparation of Glass Ceramics 17.3.3.5. Control of Transparency and Color... 

Different types of detectors have been developed and many are under development. These are based on distinctive physicochemical properties of plastics and employ different techniques such as x-ray, near-infrared spectrophotometry, fluorescence, and optical measurement of transparency and color. Automatic systems consisting of a platform for selection according to plastics topology, a number of identification and detection steps, and adequate checks on the efficiency of separation following detection have been developed. The Poly-Sort system described above is one such example. 

Transparent and colored ESD bags for content control, technical article (www. omnexus.com). SpecialChem-Omnexus 2008 (downloaded 23 July 2008). 

Pellenc Selective Technologies (PST), based in Prance, has 100 machines installed around the world for various types of waste separation. It has two plastics sorting systems. The Mistral uses NIR to identify aU materials in a single pass. The Sirocco uses a vision system to identify objects by location, shape, transparency, and color. Purity levels of 90 to 98 percent can be obtained output varies from 2 to 10 tonnes/hr. The systems can handle plastic, paper, metal, and multilayer aseptic packaging. Ottawa recently installed a Mistral system in their MRP. ... 

Gel Networks for Reversible Transparency and Color Control with Temperature. A novel class of polymer gel networks which change both their color and transparency with changing temperature has been developed (61). Starting from a... 

Chromogenic Polymer Gels for Reversible Transparency and Color Control... 

An example of a cyclosiHcate is beryl BejAljSi Ojg (Figure M58). It usually occurs in green, bluish-green, yellow or pink hexagonal prisms. Transparent and colored gem varieties include emerald, aquamarine, heliodor and golden beryl. In the tourmaline... 

Several optical properties, such as transparency and color, are crucial in determining the suitability of plastics for packaging applications. For example, the choice for a plastic alternative to glass or glass-like packaging material may be dictated by properties such as clarity and colorlessness. Visual appearance of materials is usually a result of how the material absorbs/transmits, scatters, reflects or refracts UghL... 

Figure 6.6 shows a scheme of the CIELab system. Park and Chang [20] prepared some polyimide nanocomposites films with pristine clay and analyzed the transparency and color change. This is an important aspect since colorless polyimide films have in particular been widely used in electro-optical devices and semiconductor applications. The measurements were obtained for 80 pm thick films by a spectrophotometer and the color coordinates on CIELab system were determined. 

Almost all liquid crystals are diamagnetic. An exception is made with those substances whose molecules incorporate free radicals with permanent magnetic moments. Anisotropy of electric and optical properties of the liquid crystals, closely connected with anisotropy of their molecular structure, causes variety of their electrooptical properties. The external electric field can render a very strong influence on optical properties of liquid crystals, changing, for instance, their transparency and color. Therefore they have found very wide application as electronic indicator panel in microelectronics (calculators, watches and other devices). Such types of devices require very low voltage (parts of volts) and power (pW). 

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