Data/hora: 15/06/2024 04:46:23

Biblioteca(s): | Embrapa Instrumentação.
Data corrente: | 30/03/2021
Data da última atualização: | 09/06/2022
Autoria: | FACCHINATTO, W. M.; GARCIA, R. H. S.; SANTOS, D. M.; FIAMINGO, A.; FLORES, D. W. M.; CAMPANA-FILHO, S. P.; AZEVEDO, E. R.; COLNAGO, L. A.
Afiliação: | LUIZ ALBERTO COLNAGO, CNPDIA.
Título: | Fast-forward approach of time-domain NMR relaxometry for solid-state chemistry of chitosan.
Ano de publicação: | 2021
Fonte/Imprenta: | Carbohydrate Polymers, v. 256, 117576, 2021.
Páginas: | 1 - 10
ISSN: | 0144-8617
DOI: | https://doi.org/10.1016/j.carbpol.2020.117576
Idioma: | Inglês
Conteúdo: | Chitosans 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 > 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.
Palavras-Chave: | Crystallinity; Degree of acetylation; Relaxometry; TD-NMR.
Categoria do assunto: | --
Registro original: | Embrapa Instrumentação (CNPDIA)
Exemplares: | CNPDIA - (17740-1) - UPC - AP - DD - PROCI.21/05 -  - 2021/05 - DIS