Understanding heat driven gelation of anionic cellulose nanofibrils: Combining saturation transfer difference (STD) NMR, small angle X-ray scattering (SAXS) and rheology

A novel mechanism of heat-triggered gelation for oxidised cellulose nanofibrils (OCNF) is reported. We demonstrate that a synergistic approach combining rheology, small-angle X-ray scattering (SAXS) and saturation transfer difference NMR (STD NMR) experiments enables a detailed characterisation of g...

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Detalles Bibliográficos
Autores: Calabrese, Vincenzo, Muñoz-García, Juan C., Schmitt, Julien, da Silva, Marcelo A, Scott, Janet L, Angulo, Jesús, Khimyak, Yaroslav Z, Edler, Karen J
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/413075
Acceso en línea:http://hdl.handle.net/10261/413075
https://api.elsevier.com/content/abstract/scopus_id/85054315255
Access Level:acceso abierto
Palabra clave:Heat induced gelation
Hydrogel
Rheology
SAXS
Saturation transfer difference NMR
TEMPO oxidised cellulose
Water confinement
Descripción
Sumario:A novel mechanism of heat-triggered gelation for oxidised cellulose nanofibrils (OCNF) is reported. We demonstrate that a synergistic approach combining rheology, small-angle X-ray scattering (SAXS) and saturation transfer difference NMR (STD NMR) experiments enables a detailed characterisation of gelation at different length scales. OCNF dispersions experience an increase in solid-like behaviour upon heating as evidenced by rheological studies, associated with enhanced interfibrillar interactions measured using SAXS. Interactions result in an increased fibrillar overlap and increased population of confined water molecules monitored by STD NMR. In comparison, cationic cellulose nanofibrils (produced by reaction of cellulose with trimethylglycidylammonium chloride) were found to be heat-unresponsive.