01879naa a2200289 a 450000100080000000500110000800800410001902200140006002400550007410000230012924501190015226000090027130000110028052010380029165300180132965300260134765300160137365300110138970000210140070000180142170000170143970000210145670000250147770000190150270000190152177300490154021309862022-06-09       2021    bl uuuu     u00u1 u    #d  a0144-86177 ahttps://doi.org/10.1016/j.carbpol.2020.1175762DOI1 aFACCHINATTO, W. M.  aFast-forward approach of time-domain NMR relaxometry for solid-state chemistry of chitosan.h[electronic resource]  c2021  a1 - 10  aChitosans with different average degrees of acetylation and weight molecular weight were analyzed by timedomain NMR relaxometry using the recently proposed pulse sequence named Rhim and Kessemeier - Radiofrequency Optimized Solid-Echo (RK-ROSE) to acquire 1 H NMR signal of solid-state materials. The NMR signal decay was composed of faster (tenths of μs) and longer components, where the mobile-part fraction exhibited an effective relaxation transverse time assigned to methyl hydrogens from N-acetyl-D-glucosamine (GlcNAc) units. The higher intrinsic mobility of methyl groups was confirmed via DIPSHIFT experiments by probing the 1 H-13C dipolar interaction. RK-ROSE data were modeled by using Partial Least Square (PLS) multivariate regression, which showed a high coefficient of determination (R2 &gt 0.93) between RK-ROSE signal profile and average degrees of acetylation and crystallinity index, thus indicating that time-domain NMR consists in a promising tool for structural and morphological characterization of chitosan.  aCrystallinity  aDegree of acetylation  aRelaxometry  aTD-NMR1 aGARCIA, R. H. S.1 aSANTOS, D. M.1 aFIAMINGO, A.1 aFLORES, D. W. M.1 aCAMPANA-FILHO, S. P.1 aAZEVEDO, E. R.1 aCOLNAGO, L. A.  tCarbohydrate Polymersgv. 256, 117576, 2021.