Papers by Keyword: ESCA

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Authors: Wolfgang E.S. Unger, Umut Oran, Sufal Swaraj, Andreas Lippitz
Abstract: The formation of plasma-polymerized materials made from organic molecules is a technologically attractive way to obtain films with unique properties for life science applications. Surface properties like bio-compatibility, wettability, etc., can be adjusted by tailoring the chemical functionalization. It is well known that after deposition these films undergo post-plasma reactions, especially when they are exposed to ambient atmosphere. Most often, in applications these films are not used immediately after their deposition – they are usually stored for a certain time. Therefore there is a need for a development of analytical procedures enabling studies of ageing phenomena of plasma chemically deposited films. With the help of these studies a better understanding of basic post-plasma reaction phenomena as well as relevant empiric information for practical applications can be obtained. However, a detailed chemical characterization of plasma chemically deposited films is a great challenge for the analysts because of the co-existence of a number of different chemical species. We investigated r.f. plasma-polymerized organic films by using photoelectron spectroscopy for chemical analysis (ESCA), spectroscopy of the near edge X-ray absorption fine structures (NEXAFS) and time-of-flight secondary ion mass spectroscopy (TOF-SIMS). Ethylene, styrene, allyl alcohol and allyl amine were used as monomers. A dedicated plasma preparation chamber was designed and added to the main analysis chamber of the respective spectrometer. This approach offers the possibility to study plasma-polymerized films in situ and, subsequently, the influence of post-plasma reactions. The important effect of air exposure of the film, in terms of plasma technology denominated as “ageing”, can be studied subsequentially step by step by this unique approach.
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Authors: Zhao Hui Zhen, Zheng Shun Wang
Abstract: The coating binder in cross-section of coating layer will be migrated, the binder concentration will be different in z-direction of coating layer, which affect some properties of coated paper. The paper studied the effects of coating progress on binder migration and affected factors. The z-direction distribution of the coating binder which was tagged with Br in coating layer and its concentration in coating surface were examined quantitatively by using SEM-EDXA and ESCA analysis. During coating process the drying rate, dwell time from coating device to dryer and coating weight affect the binder migration. The mechanism of binder migration was proposed. The results indicated that the degree of binder migration is directly proportional to the drying temperature and coating weight, but reduces with extending the dwell time.
187
Authors: Zhao Hui Zhen, Zheng Shun Wang
Abstract: The Paper studied the effects of coating color on binder migration and affected factors. The z-direction distribution of the coating binder which was tagged with Br in coating layer and its concentration in coating surface were examined quantitatively by using SEM-EDXA and ESCA analysis. In coating colors the coating solid content, the binder dosage and type affects the binder migration. The mechanism of coating color on binder migration was also studied. The results indicated that the degree of binder migration was increased with reduced the coating solid content or added more dosage of coating binder. In low dying temperature the SB-latex was prone to migrated to coating layer surface than starch, the opposite is true in high dying temperature.
110
Authors: Yo-ichi Takeda, M. Bojinov, Hannu Hänninen, P. Kinnunen, T. Laitinen, K. Mäkelä, T. Saario, K. Sakaguchi, Tetsuo Shoji, P. Sirkiä, A. Toivonen
Abstract: A possible approach to describe the role of the environment in the phenomena behind crack initiation and crack propagation in stress corrosion cracking (SCC) is to assume that the transport of species through the oxide film on the material surface is one of the rate-controlling factors. The transport rates of ionic and electronic defects through the oxide film are, in addition to the environment, also affected by the stress and strain applied to the bulk material. In this paper, the surface oxide film formed on AISI 316L steel in slow strain rate tests (SSRT) in simulated BWR condition has been analyzed by using Electron Spectroscopy for Chemical Analysis (ESCA). The obtained film composition and structure have been combined with in-situ contact electric resistance (CER) measurements in order to evaluate the changes in oxide film electric properties during straining in the above environment. The results show that oxide film resistance of the strained part exhibits a maximum at around 2% of strain, which seems to correlate with a maximum in the Cr(III) concentration in the inner layer of the oxide. The implications of these results to SCC are discussed based on Mixed-Conduction Model (MCM).
925
Authors: Shu Jiang Geng, Sam Zhang, H. Onishi
195
Authors: Zhao Hui Zhen, Zheng Shun Wang
Abstract: Because of the coating binder migration in cross-section of coating layer, the binder concentration will be different in z-direction of coating layer, which affect some properties of coated paper. The Paper studied the effects of pigment type, coating color solid content and dying temperature on binder migration and affected factors. The z-direction distribution of the coating binder which was tagged with Br in coating layer and its concentration in coating surface were examined quantitatively by using SEM-EDXA and ESCA analysis. The mechanism of binder migration was also proposed. The results indicated that the degree of binder migration is directly proportional to the drying temperature, that the increase of the ratio of calcium carbonate in the pigment content, coating surface binder concentration increased. The result also indicated that the degree of binder migration was increased with reduced the coating solid content.
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