Figure 2.

Solid-state 1D NMR spectra of solid PBI-1 aggregates acquired at 18.8 T (a) ¹H MAS NMR (¹H Larmor frequency = 800.1 MHz) recorded at 56 kHz MAS and (b) ¹³C CP-MAS NMR spectrum (¹³C Larmor frequency = 201.2 MHz) acquired at 50 kHz MAS using 2 ms CP contact time. ¹H and ¹³C signals correspond to aliphatic and aromatic groups are colored as depicted in the inset to (a).