ISSN:
0142-2421
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Physics
Notes:
Quantitative determination of the molecular weight and composition of submicrogram of a perfluorinated polyether (PFPE) supported on Ag and Si substrates was from empirical relationships derived from the intensities of specific high-mass (≥ 800 amu) fragmentation ions from time-of-flight secondary ion mass spectrometry (TOF-SIMS) measurements. These relationships are explained in terms of simple concepts regarding the process of volatilization, fragmentation and ionization in TOF-SIMS. The results for both negative and positive ions are nearly independent of the substrate materials used, demonstrating that the high-mass fragmentation ions in TOF-SIMS may be useful generally for in situ quantitative analysis of PEPEs on non-specific substrates. This is an important difference between the TOF-SIMS fragmentation spectrum and the complementary TOF-SIMS cationized molecular ion spectrum, which requires special sample preparation and/or substrates. In order to interpret the quantitative information available in the TOF-SIMS fragment spectrum, it was absolutely necessary to characterize extensively the PFPE samples using NMR and TOF-SIMS Ag+ -cationized molecular ion results. This characterization helped to demonstrate the power of TOF-SIMS to do quantitative analysis and led to additional insight concerning the SIMS ion-forming process for PFPE. This study represents one of the first attempts to make quantitative use of the high-mass fragment ion intensities in SIMS studies of polymers, and presents a method for confirming the origin of the mass peaks in the spectra.
Additional Material:
11 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/sia.740170303
