Plasma Cleaning and In Situ Deposition of TMS Polymer on Cold-Rolled Steel

PLASMA CLEANING AND IN SITU DEPOSITION OF TMS POLYMER ON COLD-ROLLED STEEL 

2847 and 2918 cm are due to the symmetrical and asymmetrical methylene C-H stretches. The peak expected from the symmetrical methyl C-H stretch at 2960 cm is not above the noise level of this spectrum. 

These band locations are usually associated with highly ordered, crystalline materials. However, weak bands are observed near 721 and 648 cm that are consistent with the location of the symmetrical and asymmetrical S-(CH3)3 stretching modes (not shown on these spectra). The broad band centered at 2116cm is consistent with the location of the Si-H stretching modes. The strong bands near 1000 and 840 cm are most likely associated with Si-C and Si-H 

The TMS plasma polymer deposited on the oxygen-pretreated steel surface has Si-O-Si or Si-O-alkyl chain structure, which is similar to the film deposited from a mixture of TMS and O2. Oxygen was always found in the plasma film when the steel surface was pretreated with oxygen plasma. The source of oxygen is very likely from the oxide layer. During TMS plasma deposition, oxygen redeposited with the TMS to form the final film. These results were obtained during an in situ experiment, and the treated surface was not exposed to ambient environment before the deposition of plasma polymer of TMS. Therefore, the influence of oxides on the chemical structure of plasma polymer of TMS is quite evident. 

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