Data/hora: 23/09/2024 13:04:21

Biblioteca(s): 	Embrapa Instrumentação.	
Tipo da produção científica: 	Artigo em Periódico Indexado	
Circulação/Nível: 	A - 1	
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