Sulfonation of poly(N-vinylcarbazole) studied by combined time of-flight secondary ion mass spectrometry and X-ray photoelectron spectroscopy

A series of sulfonated poly(N-vinylcarbazole) (PVK) samples have been syste matically studied by time-of-flight secondary ion mass spectrometry (TOF-SM S) and X-ray photoelectron spectroscopy (XPS). Negative TOF-SIMS results pr ovided unambiguous evidence that sulfonate groups are chemically attached t o the carbazole moiety of PVK. The positive SIMS spectrum of PVK was, howev er, little affected by the sulfonation reaction. The degree of sulfonation was quantitatively determined by XPS, Therefore, the combination of TOF-SIM S and XPS is useful to follow the sulfonation reaction, both qualitatively and quantitatively. The SIMS intensities of some characteristic fragments a re linearly related to the degree of sulfonation, suggesting that quantitat ive analysis is possible from TOF-SIMS data.