Surface chemical analysis

Chemical analysis of surfaces and in particular of polymers Is made possible by probing with photons (soft X-rays) or ions [5,6]. The principle of chemical surface analysis is illustrated schematically in Fig. 1. A primary source is directed towards the surface of a solid sample and the spectrometer measures properties of 

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Main use Surface chemical analysis, particularly organics, poly-... 

Surface Chemical Analysis. Electron spectroscopy of chemical analysis (ESCA) has been the most useful technique for the identification of chemical compounds present on the surface of a composite sample of atmospheric particles. The most prominent examples Include the determination of the surface chemical states of S and N in aerosols, and the investigation of the catalytic role of soot in heterogeneous reactions involving gaseous SO2, NO, or NH3 (15, 39-41). It is apparent from these and other studies that most aerosol sulfur is in the form of sulfate, while most nitrogen is present as the ammonium ion. A substantial quantity of amine nitrogen also has been observed using ESCA (15, 39, 41). 

The chemistry of surfaces or interfaces is becoming increasingly important in a variety of scientific disciplines, including the environmental sciences. In the case of atmospheric particles, modern methods of surface chemical analysis are providing valuable insights into the chemical speclation, mechanisms of formation, sources, reactivity, and potential toxicity of pollutant species. 

Paik, C. S., Hu, C. B. Surface Chemical Analysis of Segmented Polyurethanes. Fourier Transform IR Internal Reflection Studies in Advances in Chemistry Series,Cooper, S., Estes, G. (Eds) 176, 69 (1979)... 

From the perspective of this symposium, analysis of the atomic dynamics and electronic structure of surfaces constitutes an even more exotic topic than surface atomic geometry. In both cases attention has been focused on a small number of model systems, e.g., single crystal transition metal and semiconductor surfaces, using rather specialized experimental facilities. General reviews have appeared for both atomic surface dynamics (21) and spectroscopic measurements of the electronic structure of single-crystal surfaces (, 22). An important emerging trend in the latter area is the use of synchrotron radiation for studying surface electronic structure via photoemission spectroscopy ( 23) Moreover, the use of the very intense synchrotron radiation sources also will enable major improvements in the application of core-level photoemission for surface chemical analysis (13). 

Surface Chemical Analysis of Polymeric Drug Delivery Systems by Static Secondary Ion Mass Spectrometry (SSIMS) and SIMS Imaging... 

The clear and unequivocal in situ surface chemical analysis of... 

Characterization of the state, nature and structure of the starch granule surface has been somewhat limited. Over the past few years, however, substantial progress in starch surface chemical analysis and surface imaging has been made. The following two sections detail recent developments in these two new areas of starch research. 

Surface Chemical Analysis of Segmented Polyurethanes. Fourier Transform IR Internal Reflection Studies... 

Another important factor that is often not taken into consideration is the process temperature during polishing. Recent researches [12,13] have elucidated the effect of temperature on the coefficient of friction during both copper and ILD CMP by conducting polishing experiments at different pad and slurry temperatures. Sorooshian et al. [12] have attributed the changes in coefficient of friction to the changes in pad properties, which result in an increase in shear force. Conversely, removal rate, surface chemical analysis. 

Table 21.7 Surface Chemical Analysis of Composition-Graded Film Layered by the Double-Graded Process [eopper eleetrode used] after Extended Time (48 h) Exposure to Atmosphere...

XPS and AES are powerful tools for surface chemical analysis. They can identify chemical elements in the layer within several nanometers from the surface. Importantly, peak positions... 

Secondary ion mass spectrometry (SIMS) is a relatively new technique for surface chemical analysis compared with Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). SIMS examines the mass of ions, instead of energy of electrons, escaped from a solid surface to obtain information on surface chemistry. The term secondary ion is used to distinguish primary ion that is the energy source for knocking out ions from a solid surface. The advantages of SIMS over electron spectroscopy are ... 

Appearance potential spectroscopy involves detection of electronic transitions not of the backscattered electrons as in ELS, but of secondary processes. The latter include increase in soft X-ray (SXAPS) or Auger electron (AEAPS) emission or decrease in elastically scattered primary electrons (DAPS) (382). SXAPS is not as sensitive as AES for surface chemical analysis. However, SXAPS and IS spectra are easier to analyze than AES, since only one core transition is involved. This makes SXAPS and IS quite convenient for detecting heavy elements on catalyst surfaces. 

Lee, P. I. and Good, W. R., Eds. Surface chemical analysis of polymeric drug delivery systems by static secondary ion mass spectrometry (SSIMS) and SIMS imaging. In American Chemical Society Symposium Series Controlled-Release Technology, Pharmaceutical Applications. American Chemical Society, Washington, DC, 1987. 

Plaza, R.C. et al.. Surface chemical analysis and electrokinetic properties of spherical hematite particles coated with yttrium compounds,. 1. Colloid Intetf. Sci., 194, 398, 1997. 

Jensen, K. Huff, E. Williams, F. Youngdahl, A. "Developmental Procedure of Stone Surface Chemical Analysis" Report to NPS from ANL, in press. 

Polymer Treatment Surface Chemical Analysis (%) by ESCA Bond Strength, Mpa ... 

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