Mirrors, coating

Lead sulfide is used in photoconductive cells, infrared detectors, transistors, humidity sensors in rockets, catalysts for removing mercaptans from petroleum distillates, mirror coatings to limit reflectivity, high temperature solid-film lubricants, and in blue lead pigments (82). 

Vacuum chamber for mirror coatings becomes very large and expensive... 

All telescopes suffer from this thermal background, depending on the temperature of the telescope and its optics. In practice, telescopes with clean and freshly applied mirror coatings (such as silver) have emissivities >1% per surface at wavelengths beyond 1/rm. Of course as the optics degrade with time, dirt, etc. theemissivity will grow. 

Abstract The principles of coatings to either enhance reflectivity of mirrors or to enhance transmission of glass optics are described. Then the ion assisted deposition and ion beam sputtering techniques are addressed. Performances of these technique-sand their limitations are illustrated with the characteristics of the VIRGO mirrors coated at LMA. The importance of metrology is emphasized. 

Figure 15. Antireflection glass mirror coated with a 10 nm layer of Gr, with a 100 nm layer of MgF2 plus a 3 nm layer of Al.

Anticorrosive pigment Air- drying alkyd primers Alkyd- melamine primers 2-Compo- nent epoxy primers 2-Compo-nent acrylic isocyanate primers Chlor- inated rubber primer Aqueous polymer dispersions Poly(vinyl- butyral) primers Electro- deposition coatings Mirror coatings References... 

Mainly on aluminum. Mirror coatings are used to protect the thin metal surface (silver, copper) of metal-coated glass against oxidation or reaction with H2S or S02. 

The main fields of application are in mirror coatings [5.77], [5.125], electrodeposition coatings, and primers (see Table 39). 

Equation 18-14 says that, at low concentration, emission intensity is proportional to analyte concentration. Data for anthracene in Figure 18-22 are linear below 10 6 M. Blank samples invariably scatter light and must be run in every analysis. Equation 18-14 tells us that doubling the incident irradiance (P0) will double the emission intensity (up to a point). In contrast, doubling P0 has no effect on absorbance, which is a ratio of two intensities. The sensitivity of a luminescence measurement can be increased by more than a factor of 3 by the simple expedient of using a mirror coating on the two walls of the sample cell opposite the slits in Figure 18-20.15... 

B. Fanget, O. Devos, and M. Draye, Correction of Inner Filter Effect in Mirror Coating Cells for Trace Level Fluorescence Measurements, Anal. Chem. 2003, 75, 2790. 

A solar thermal electric-generation unit. A pipe containing synthetic oil is positioned along a mirror-coated trough. Sunlight hitting the mirror is reflected onto the pipe and heats the oil to 370°C. The hot oil is then pumped out and used to convert water to steam in a turbine in an electric power plant. 

These conclusions were supported by results obtained from angle-resolved XPS. The band near 932.4 eV in the Cu(2pV2) photoelectron spectrum of the mirror coated with y-APS increased in intensity relative to that near 934.9 eV when the take-off angle was increased from 15° to 75°. Similarly, the band near 336.8 eV in the Auger spectrum also increased in intensity relative to that near 340.0 eV. Such behavior would be expected if the bands near 932.4 eV in the photoelectron spectrum and near 336.8 eV in the Auger spectrum were related to an oxide that was covered by a thin film of silane. 

The interaction between these films and bulk epoxy resin was assessed by immersing an aluminum mirror coated with an air-dried primer film in a Petri dish filled with the epoxy resin, heating the dish in an oven at 100°C for 1 h, allowing the dish to cool overnight, and then extracting any unreacted material from the surface of the mirror by MEK extraction. Figure 6A is the reflection spectrum of a relatively thick film (ca. 3 / n) of neat DGEBA resin (cast onto polished aluminum from a 3% solution in toluene), and Fig. 6B shows the RAIR spectrum obtained from the mirror that was primed, heated in resin, and extracted. The... 

The cell has an optical capability of 2.5 m, using 12 transversals. When applied to CO2, however, the absorption coefficient (ac) is of sufficient size to allow measurements using an 0.5 m (4 transversals) path. Due to the magnitude of ac, a large difference in intensity develops as the beam passes through the cell. Maximum detection and amplification efficiency can only be achieved when the intensity levels of the sample and reference beams are approximately the same. To help balance the intensity levels, the mirror coatings (multi-layer silicon/silicon dioxide) have been optimized to pass the sample beam (99 percent reflectance at 4.3 pm) and partially attenuate the reference wavelength (95 percent... 

The phase shift < j due to the mirror coatings is eliminated by the method of... 

Coatings Powder Coatings Liquid Coatings Conductive Coatings Mirror Coatings... 

For very specific and limited applications the following lead-based products have been used lead suboxide, lead carbonate and lead cyanamide (mirror coatings), lead silicate (electro disposition primers), dibasic lead phosphate, tribasic lead phosphate silicate, and calcium plumbate [5.51, 5.53]. 

Zinc cyanamide (Zn(CN)2) was developed as a replacement for lead cyanamide (see Section 5.2.4.1) mainly for application in mirror coatings. The electrochemical effectiveness of cyanamides is attributed to a passivation action under alkaline conditions [5.56]. 

Zinc cyanamide is produced on an industrial scale from pure calcium cyanamide in an aqueous medium with zinc salts or a slurry of zinc oxide [5.56]. The pigment has, until now, not reached the importance of lead cyanamide for application in mirror coatings. 

Ray and Coombe achieved lasing of the NCI (a)/I system by scaling-up their quenching experiment. The apparatus used for this demonstration is shown in Fig. 10. An excimer laser capable of providing 700 mJ pulses at 193 nm was used to generate high densities of NCI (a) metastables. The I laser cavity consisted of mirrors coated for > 99.5% reflectivity at 1.315 m. Representative I emission signals from this device are shown in Fig. 11. 

Figure 1.38. A double-sided video disk. Abbreviations are as follows S is the transparent substrate, A is the adhesion layer, L is the polymeric information layer with picture and sound information in the form of pits, M is the mirror coating, PR is the protective layer, and G is the adhesive layer holding both sides together. Reproduced with permission from reference 55. Copyright 1982 Philips Research Laboratories.)...

Use Amalgams, catalyst, electrical apparatus, cathodes for production of chlorine and caustic soda, instruments (thermometers, barometers, etc.), mercury vapor lamps, extractive metallurgy, mirror coating, arc lamps, boilers, coolant and neutron absorber in nuclear power plants. 

Photographs of the moon obtained with a 30 cm telescope mirror coated with rhodium (a) and with silver (b). The photos were made in Berlin in 1938 [91]. As can be seen by observation of the craters a sharper and halo-free picture was obtained with the rhodium mirror as a consequence of the finer grained and smoother coating. 

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