13C CPMAS solid-state NMR spectra of cellulose III
prepared by treatment with liquid ammonia. (A) At 25°C and (B) 130°C from various cellulose I samples. (a) Avicel, (b) α-cellulose, (c) cotton linters, and (d) corn stover, (e) amorphous cellulose. CPMAS: cross polarization and magic angle spinning solid-state; NMR: nuclear magnetic resonance.