Fluorine peak

In Figure 15.2 Pictures 1.1 and 2.1 are SEM images of nonfluorinated (reference) material and fluorinated samples (Batch 15A20PR7), and Pictures 1.2 and 2.2 are the corresponding X-ray spectra. The EDS spectrum shows that Batch 15A20PR is fluorinated, since a fluorine peak can be seen in the left part of the spectrum (Picture 1.2). 

We associate the various additional fluorine peaks observed in the NMR spectra with principally the products of epoxide-active fluorine species reactions. The total fluorine in the form of these products is relatively constant from prepreg lot to lot (28.2 to 36.3%). 

EDX analysis results showed that iron, nickel, and chromium, all typical components of stainless steel, were present. The fluorine peak was weaker in this area than in the normal areas. No evidence of an external piece of metal or wire being trapped in the crack was detected. All data suggested that the source of contamination must have been mixed with the PTFE prior to or during the fabrication of the tube. 

Fluorine absorption is also sensitive to the environ-ntcni. and the resulting chemical shifts extend over a range of about. 3(H) ppm. In addition, the solvent plays a much more important role in determining fluorine peak positions than in determining those of protons. 

LiAsFg, LiPFe, and LiC(S02CF3)3 solutions (23a-c, respectively)/ " The fluorine peaks in Figures 23a-c and the arsenic, phosphorous, and sulfur peaks in Figures 23a, b, c, respectively, clearly demonstrate the strong involvement of the salt anions reduction processes in the surface film formation on Li. 

Studies under XFS confirm a sharp decrease in fluorine peak and a small increase in nitrogen peak, resulting in an increase in hydrophilic properties of the polymer. 

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