ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Recently, it was demonstrated that copper thin films show good adsorptioncharacteristics for organic polar and non-polar compounds. Also, these films when used in smallcavities can favor preconcentration of these organic compounds. It is also known that copper oxidecan provide catalysis of organic compounds. Therefore, the aim of this work is the study of copperthin film catalysis when used in small cavities. Copper thin films, 25 nm thick, were deposited onsilicon and/or rough silicon. These films do not show oxide on the surface when analyzed byRutherford backscattering. Also, Raman analysis of these films showed only silicon bands, due tothe substrate, however infrared spectroscopy shows oxide bands for films exposed to organiccompound aqueous solutions. Cavities with copper films deposited inside were tested with acontinuous flow of n-hexane, acetone or 2-propanol admitted in the system. The effluent wasanalyzed by Quartz Crystal Microbalance. It was shown that n-hexane or acetone can be trapped.The system also shows good reproducibility. Tests of catalysis were carried out using Ramanspectroscopy and heating the films up to 300ºC during 3 minutes after exposure to n-hexane, 2-propanol and acetophenone – pure or saturated aqueous solution. After the exposure, Raman spectrapresent intense bands only for 2-propanol, indicating that adsorption easily occurs. However, afterheating with all solutions it was not found only silicon bands. Raman microscopy after heating alsoshowed copper oxide cluster formation and, eventually, graphite formation. Although the heatingprovides oxide copper formation, this reaction does not produce a high amount of residues, whichmeans that catalysis is possible in this condition. Thus, a simple device using copper thin films canbe useful as sample pretreatment on microTAS development
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/12/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.514-516.1328.pdf
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