Standardless, Quantitative SIMS Using the Full Spectrum Method (FSM): Part I. Polymers

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a powerful surface-analytical method extensively used in a variety of scientific fields and industrial sectors. However, quantitative ToF-SIMS analyses are challenging and limit the broader applicability of this characterization technique. This study demonstrates the use of the full spectrum method (FSM) as a quantitative technique for analyzing homopolymers (e.g., polypropylene (PP), polystyrene (PS), and polytetrafluoroethylene (PTFE)) using ToF-SIMS. By analyzing the entire collection of sputtered secondary ions, FSM minimizes "matrix effects" that commonly impede the quantitative ToF-SIMS analysis of polymers. The results indicate that the acquisition of ToF-SIMS data should be carried out while varying the primary ion fluence. This approach yields experimental data that can be directly compared with theoretical predictions of ion-induced surface damage, thus providing unambiguous evidence for the effect of ion bombardment and whether the quantification was performed with clusters whose intensity is affected by ion-induced damage. Overall, the outcomes of this work establish FSM as a powerful tool for multicomponent analysis, advancing the precise surface characterization of polymeric materials via ToF-SIMS.