期刊
SURFACE AND INTERFACE ANALYSIS
卷 53, 期 3, 页码 340-349出版社
WILEY
DOI: 10.1002/sia.6922
关键词
interface; isocyanates; MVA; ToF‐ SIMS; XPS
The interactions between pMDI and a Fe-Cr alloy were studied using XPS and ToF-SIMS, with MVA methods identifying specific ions and chemical species related to the interfacial region. Two complementary reaction mechanisms were proposed based on the data, with a range of cluster ions used for analysis. A repeat of ToF-SIMS sputter profiles in a different system using argon cluster ions ensured direct comparability of the data.
The interactions of polymeric methylene diphenyl di-isocyanate (pMDI) and a model Fe-Cr alloy have been studied by X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Films of two different thicknesses have been investigated: one with an extremely thin pMDI layer in which the interfacial chemistry can be probed directly and a thicker one in which sputter profiling using cluster ions is necessary to expose the interface chemistry for direct analysis. Multivariate analysis (MVA), using principal component analysis (PCA) and nonnegative matrix factorisation (NMF), has been used to identify specific ions associated with the interfacial region of the ToF-SIMS sputter depth profile and chemical species from the XPS sputter depth profile. As an unsupervised method, this avoids an unconscious bias on the part of the analyst. Specific ions associated with pMDI interactions with both Fe and Cr allow the proposal of two complementary reaction mechanisms, supported by the XPS data. A range of cluster ions is used in this investigation, but the bulk of the work used argon clusters for the XPS depth profiles and Buckminster Fullerene projectiles for the ToF-SIMS analyses. To ensure that such data were directly comparable, the ToF-SIMS sputter profiles were repeated in a different system of the same type using argon cluster ions.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据