X-ray photoelectron spectroscopic studies of ionic interactions in poly styrenesulfonic acid/rpoly vinylpyridine/ complexes

X-ray photoelectron spectroscopic XPS.measurements were made on complexes obtained from poly styrenesulfonic acid. PSSA. and poly 4-vinylpyridine. P4VPy. or poly 2-vinylpyridine. P2VPy.. Ionic interactions in the complexes are evidenced by the development of a high-binding energy component of the N1s spectra. The extent of protonation of pyridine groups, ranging from 34 to 86%, is a linear function of the surface composition of the complex. As compared to the poly vinylphosphonic acid. PVPA.rpoly vinylpyridine. complexes, protonation is more extensive in the PSSArpoly vinylpyridine.complexes. The position of the nitrogen in the pyridine ring does not have a significant effect on the extent of protonation. Fourier-transform infrared FTIR.spectroscopy also showed the existence of ionic interactions in the various complexes. q1998 Elsevier Science B.V.