Controlled sulfonation of poly(N-vinylcarbazole)

Poly(N-vinylcarbazole) (PVK) was sulfonated with acetyl sulfate. SIMS and X PS measurements of the sulfonated PVK show that the sulfonation occurs on t he carbazole moiety and that the degree of sulfonation (DS) increases linea rly with the ratio of the sulfonating agent to PVK. The DS of PVK could be controlled within a range from 12% to 28% by varying the reagent ratio. GPC measurements demonstrate that the molecular weight of PVK did not change s ubstantially after sulfonation. UV-vis and photoluminescence spectra indica te that the sulfonation caused little change in the electronic structure of the PVK molecules but reduced significantly its photoluminescence quantum efficiency.