Dye coating

Lakes are prepared by adsorption or precipitation of a soluble dye on an insoluble substrate (e.g., alumina). They are useful in fatty products that have insufficient moisture to dissolve dyes (coated tablets, cake mixes, hard candies, chewing gum). Lakes are insoluble in most solvents including water, have high opacity, are easily incorporated in dry media, and show higher stability to light and heat. They are effective colorants for candies, pills, fats, and oils. The main characteristics and differences between lakes and dyes are well documented. ... 

Toluene Industrial solvent used in the manufacture of explosives, dyes, coatings and other organic substances and as a gasoline additive. 

The dye-sensitised solar cell (DSSC) is constructed as a sandwich of two conducting glass electrodes filled with a redox electrolyte. One of the electrodes is coated, using a colloidal preparation of monodispersed TiOj particles, to a depth of a few microns. The layer is heat treated to rednce resistivity and then soaked in a solution of the dye until a monomolecnlar dispersion of the dye on the TiO is obtained. The dye-coated electrode (photoanode) is then placed next to a connter electrode covered with a conducting oxide layer that has been platinised , in order to catalyse the reduction of the mediator. The gap between the two electrodes is filled with an electrolyte containing the mediator, an iodide/triodide conple in acetonitrile. The structure is shown schematically in Fignre 4.29. 

We usually prepare an unsealed DSSC and measure its photovoltaic performance. A spacer film, such as polyethylene (15-30 pm thickness), is placed on the dye-coated 2 photoelectrode and then the electrolyte solution is dropped on the surface of the Ti02 photoelectrode using a pipette (one or two drops). The counterelectrode is placed over the 2 photoelectrode and then the two electrodes are clipped together with two binder clips. If a low-melting-point polymer film such... 

On the other hand, Tennakone and co-workers utilized a p-type semiconductor material, such as Cul (band gap,-3.1 eV), as a hole conductor and produced a solid-state DSSC [141,145,146]. Acetonitrile solution of Cul was dropped onto the surface of a dye-coated Ti02 film, which was heated up to approximately 60°C and then the solution penetrated into the film. After evaporation of the acetonitrile, Cul was deposited into a nanoporous Ti02 film. The Au-coated TCO substrate as the counterelectrode was pressed onto the surface of the Ti02/dye/ Cul film. In the system using the santalin dye photosensitizer, an efficiency of 1.8% was obtained under irradiation of 80 mW/cm2 [141] and the efficiency reached 4.5% for the Ti02/N3 dye/CuI/Au system. These results suggested that a highly efficient solid-state DSSC could be produced [145]. In these systems,... 

One method used to position the energy levels of the dyes relative to those of the silver halide depends on the measurement of ionization potentials of the dyes adsorbed by a substrate. Nelson (251,252) measured ionization potentials of several sensitizing dyes coated on a variety of substrates ... 

Tonelh, D., Zappoh, S., andBaUarin, B. Dye-coated stationary-phases a retention model for anions in ion interaction chromatography. Chromatographia 1998, 48, 190-196. 

Li J, Xu JB, Ong HC (2009) Hole size dependence of forward emission from organic dyes coated with two-dimensional metallic arrays. Appl Phys Lett 94 241114... 

The imagewise silver negative is formed during the development step. In the dye-bleach the dye coats in the film are bleached where silver is present, and remain in the area where there is no silver. In this way a positive image is built up. Thirtle gives a detailed description of the process [116a]. 

In another example of separating coal from slate, fluoranthene is dissolved in decylalcohol which is then dispersed into water. Results of separation of fluorescent dye coated coal particles from uncoated slate pieces using the Oxylore sorting machine are presented in Table ill. (3 )... 

Figure 3.13. Formation of self-assembled dye-coated nanoparticles resulting in a tremendous increase of 3. (Adapted from Ref. [349].)...

The generation of a photocurrent upon illumination of a dye coated onto a metal electrode has long been a topic of research... 

Garof et found similar results for R6G on silver films. They study the optical density of the dye-coated films as a function of dye concentration (in the solution from which it is adsorbed on the silver) and as a function of film thickness. The double peaks appeared and were explained on the basis of Mie formalism. Note that significant changes in the spectrum shape appear only from a concentration of 2.8 x M. Also no determination of the amount... 

Wang and Kerker" and Chew and Wang" " have presented a theoretical treatment, based on the electrodynamic approaches used for the SERS problem, and provide a full description of the extinction of the dye-coated spheroids. They also calculated the luminescence enhancement, and find it to be up to 10" on silver for optimal wavelengths and particle shapes. 

Fig. (20). Photoanode consisting of titania sensitized Ru dye coated over a nafion layer doped with manganese based water oxidation catalyst along with the cross sectional arrangement of photoelectrochemical cell. Reproduced with permission from Ref. [179] 2010 American Chemical Society.

Dye-Sensitized Cells Dye-sensitized solar cells (DSSCs) are slightly more complex than bilayer and bulk heterojunction cells, but as was the case for bilayer cells, the increase in device complexity reduces the number of functions that must be performed by each of the materials. A schematic drawing of a dye-sensitized solar cell is shown in Fig. 8.8. A layer of sintered, interconnected TiC>2 nanoparticles, which serves as the electron transport material (ETM), is coated by a thin layer of light absorbing dye. The remaining pores in the dye-coated TiC>2 layer are then filled with a... 

Figure 14.36 Schematic construction of (a) a pyrite-iodine (FeS2-l2) photoelectrochemical cell and (b) a dye sensitised titanium dioxide (Ti02) photoelectrochemical cell. In both cells the generation of electron and hole pairs by the interaction of photons from the sun, with the semiconducting pyrite crystal in part (a) and with the dye coated onto the Ti02 in part (b), leads to power output. The cell is completed by an internal oxidation-reduction cycle involving iodide ions. The thin arrows show the electron and hole paths in the cell...

In September 2000, Hayazawa and coworkers reported the next study on apertureless SNOM using a silver-coated cantilever and a dye-coated silver film on a glass slide [137]. The dye was rhodamine 6g (Rh-6g). A 40-fold enhancement of Raman scattering was observed with a 4 8-nm laser excitation an enhancement of fluorescence was also noticed (see Fig. 10.16) [137]. The authors observed bleaching behavior for rhodamine 6g, but did not mention whether or not the bleaching rate was tip-enhanced. Instead, they pretreated this system with 20-min illumination until a stationary state was reached. 

Chem. Desetip. Stearalkonium bentonite Uses Rheology control agent for high polarity and oxygenated solv. systems such as nail laquers and industrial uses incl. lubricants, penetrants, inks, plasticizers, pigments/dyes, coatings Properties Lt. cream powd. 90% < 88 pm particle size sp.gr. 1.7 dens. 14.16 Ib/gal bulking value 0.0706 gal/lb 3% max. moisture content... 

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