Erin Kingston

• Northeastern University

The dehydration of SPEEK-[H] (protonated sulfonated poly(ether ether ketone)) converts 3-fold symmetric (C3V) hydrated sulfonate sites to sulfonic acid sites with no local symmetry (C1). Like Nafion-[H], SPEEK-[H] C3V and C1 environments afford IR group modes (C3V,HF (1087 cm-1); C3V,LF (1026 cm-1) and C1,HF (1362 cm-1); C1,LF (904 cm-1)) due to th...

The categorization of Nafion side-chain IR group modes by exchange site local symmetry enables correlation of exchange site structure to state-of-hydration and ion exchange. During dehydration the Nafion-[H] exchange site transitions from the sulfonate to sulfonic acid form, corresponding to C3V and C1 symmetry, respectively: C3V,HF (1061 cm-1) and...

Time-dependent FT-IR spectra of sulfonated poly(ether ether ketone) during dehydration show diminishing 1081 cm(-1) and 1023 cm(-1) band intensities concurrent with the emergence and shifting of bands at 1362 cm(-1) and 898 cm(-1). Animations of density functional theory calculated normal modes enable assignment of the 1081 cm(-1) and 1023 cm(-1) b...

The time-dependent IR spectra during dehydration of fully hydrated Nafion show the reversible disappearance of the 1061 cm−1 and 969 cm−1 concurrent with the emergence of peaks at ∼928 cm−1 and ∼1408 cm−1. The first pair of group modes is associated with a dissociated exchange group (sulfonate) with a local C3V symmetry. The C3V group modes shift w...

This paper summarizes the progress achieved over the past fifteen years in applying vibrational (Raman and IR) spectroscopy to problems of medical diagnostics and cellular biology. During this time, a number of research groups have verified the enormous information content of vibrational spectra; in fact, genomic, proteomic, and metabolomic informa...