Dye in polymer

Dyeing accelerants Dyeing classes Dyeing of leather Dyeing paper Dyeing processes Dye initiators Dye-in-polymer systems Dye intermediates... 

Polymers are only marginally important in main memories of semiconductor technology, except for polymeric resist films used for chip production. For optical mass memories, however, they are important or even indispensable, being used as substrate material (in WORM, EOD) or for both substrate material and the memory layer (in CD-ROM). Peripheral uses of polymers in the manufacturing process of optical storage media are, eg, as binder for dye-in-polymer layers or as surfacing layers, protective overcoatings, uv-resist films, photopolymerization lacquers for repHcation, etc. 

WORM writablenot erasable polymeric or glassy substrates with metal or ahoy layer, dye-in polymer film substrate <51/4 in./ PC0 > 51/4 in. glass, partly PC... 

A special implementation of the CD-R disk is the Photo-CD by Kodak which is a 5.25 in. WORM disk employing the dye-in-polymer principle for storage of up to 100 sHdes /pictures on a CD (after data compression) with the possibhity of interactive picture processing. 

Writing by Bubble Forming. Bubble formation occurs under thin metal layers on polymeric substrate films, caused by local evaporation when hit by a focused laser beam (see Fig. 3c). Bubble formation occurs as in the DIP concept in dye-in-polymer films which are covered by a thin metal (mostiy gold) or ceramic layer (6) (see Fig. 3d). 

Dyes for WORM-Disks. Regarding their memory layer, dye-in-polymer systems show advantages over metal layers in their higher stabiHty, lower toxicity, lower heat conductivity, lower melting and sublimation temperature, and simpler manufacturing technique (substrate coating by sublimation or spincoating). 

The Dye-in-Polymer concept was first proposed and reduced to practice in our laboratory (12). It involves the ablative marking with an appropriate laser, of a polymer film containing a dissolved dye. The dye-in-polymer film can be easily prepared by spin-coating a dye/polymer solution onto a reflective substrate. The structure of the DIP recording medium is shown in Figure 8. 

The reflectivity of the marks, (Rf — Rf, was measured as a function of pulse energy. At high pulse energies, the reflectivity saturates indicating that all the dye in polymer material is removed. Furthermore, the reflectivity of very large marks was approximately 90% (identical to that of the aluminum reflecting layer). The signal contrast, C, was therefore, as expected, equal to 0.7. 

Figure 16. Reflectivity change in the dye-in-polymer films as a function of time for a series of polystyrene samples of different molecular weights.

So far, the selection of polymers for chemical sensors based on fluorescent dyes in polymer matrices has been largely empirical, based on the accomplishment by the polymer of a number of requisites that are desirable for any support aimed to be used in optical sensing. These features are the following ... 

Lefe, P., Fiorini, C. and Nunzi, J.-M. (1998). Anisotropy of the photo-induced translation diffusion of azobenzene dyes in polymer matrices. Pure Appl. Opt. 7 71-82. 

Sckkat, Z., Aust, E. F., and Knoll, W. Photo-induced poling of polar azo dyes in polymer films. In G. Lindsay and K. Singer, Eds. Polymers for Second-Order Nonlinear Optics, ACS Symp. Set. 601, Ch. 19, 1995. 

This chapter is divided into six sections. Section 11.2 gives a short introduction into the optical and electronic properties of mostly used phosphorescent dyes. In Section 11.3, mechanisms of excitation of these dyes in polymer hosts will be discussed. The optimization of green, red, blue and white devices based on a PVK host is the subject of Section 11.4. The following two sections present selected examples of devices with conjugated polymer hosts or using fully functionalized polymers. Finally, a short conclusion and outlook summarize the current status of phosphorescent polymer LEDs. 

Karstens and Kobs have compared rhodamine B (25) and rhodamine 101 (26) as fluorescence quantum yield reference substances. For rhodamine 101 the quantum yield was 1.0 at all the temperatures investigated. This was not true for rhodamine B, and at room temperature d)p 0.5. A number of luminescence quantum counters based on organic dyes in polymer matrices have been described. " Poly(vinyl alcohol) films are suitable for water-soluble dyes, and poly(vinylpyrrolidone) is compatible with dyes soluble in organic solvents. 

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