Film coating period

Zhang, J. Tang, X. Dong, J. Wei, T. Xiao, H., Zeolite thin film coated long period fiber grating sensor for measuring trace chemical, Opt. Express 2008, 16, 8317 8323... 

Pilla, P. Foglia Manzillo, P. Giordano, M. Korwin Pawlowski, M. L. Bock, W. J. Cusano, A., Spectral behavior of thin film coated cascaded tapered long period gratings in multiple configurations, Opt. Express 2008, 16, 9765 9780... 

B. D. Hatton, K. Landskron, W. Whitnall, D. D. Perovic and G. A. Ozin, Spin Coated Periodic Mesoporous Organosilica Thin Films Towards a New Generation of Low-Dielectric-Constant Materials, Adv. Fund. Mater., 2005, 15, 823. 

As the absorption of water from the air is particularly critical in the film-coating of tablets, it was tested with cast films of povidone K 30 that contained 2.5% glycerol as a plasticizer. Figure 17 shows that a film of this type absorbs significantly less water within 72 hours at 85% relative humidity than the powder in Fig. 15. The absorption of moisture from the air is not completed within this period of time. 

Polyester can be formed into a film called Mylar. These films, coated with aluminum foil, are used to make balloons that remain inflated for long periods. They are also used as the base for recording tapes and photographic film. 

In multilayer production the growing Si02 film is periodically doped resulting in a sinusoidal film refractive index profile. The almost monolayer-by-monolayer growth control offers a new degree of freedom in optical coating design. 

Chemical durability of materials is another research topic of importance. The tiny structures which are exposed to the harsh chemical environment inside the micro-TAS must be extremely stable chemically. Etching rates must be well below 1 A/h if 1 pm thick structures or a thin film coating are to be used for more than one year. The stability of the reagents used in the system must also be investigated if maintenance-free periods of a half year or more are to be achieved by the system. 

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