Thin films improving quality

For recording applications, new approaches to high-quality polymeric film substrates are needed. Improved automation and control of thin-film coating are also important. 

As described earlier, the covalently bonded hydrogen, by passivating dangling bond defects and removing strained weak Si—Si bonds from the network, dramatically improves the semiconducting quality of amorphous silicon. Hence without the presence of hydrogen, effective amorphous semiconductor devices such as solar cells or thin film transistors would not be possible. Unfortunately, low defect density, high electronic quality... 

Whereas the surface interaction between [Mo(CO)6] and oxide supports were extensively studied and reactivity features generally well described, in depth characterization of the final deposif was offen neglecfed in the spectroscopic studies. On the other hand, many CVD studies carried out with zerova-lent carbonyl precursors revealed that incorporation of significant amounts of carbon and oxygen takes place. Additional studies are thus needed to correlate the influence of the state of the surface of the substrate to the chemical purity of the deposited ultra-thin films or nanoparticles. Probably, and as shown in other cases, the addition of a reactive gas in the system could also improve the quality of the films. 

These conducting polymers are sometimes termed organic metals, and their formation as thin-film coatings on an electrode involves nucleation phenomena so perhaps by analogy with metal electrodeposition under ultrasound there have been studies to improve the quality of the deposited materials. Polypyrrole readily forms acceptable films under a wide variety of conditions [174], although there are subtle distinctions in behavior as a result of exact preparation procedure [175], Ultrasound from 38 or 500 kHz baths does not appear to appreciably improve polypyrrole film formation, at least from MeCN electrolyte at the normal current density of 1 mAmp... 

There are three types of deodorization operations. The batch process is the least common, due to its low efficiency and inconsistent product quality. Semi-continuous and continuous deodorizers have improved processing efficiency. There are several configurations of the continuous deodorizer, including singleshell cylindrical vessel type, vertically stacked tray type, and the thin-film packed column type. This last provides excellent fatty acid stripping with minimum use of steam, but it achieves neither desired heat bleaching nor effective deodorization due to the relatively short retention time. A retention vessel has to be used after the column distillation (De Greyt and Kellens 2000). 

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