Understanding heat driven gelation of anionic cellulose nanofibrils: Combining saturation transfer difference (STD) NMR, small angle X-ray scattering (SAXS) and rheology
Understanding heat driven gelation of anionic cellulose nanofibrils: Combining saturation transfer difference (STD) NMR, small angle X-ray scattering (SAXS) and rheology
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DOI：
10.1016/j.jcis.2018.09.085
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发表时间：
2019-02-01
影响因子：
9.9
通讯作者：
Edler, Karen J.
中科院分区：
文献类型：
--
作者：
Calabrese, Vincenzo;Munoz-Garcia, Juan C.;Edler, Karen J.
报道了氧化纤维素纳米原纤维（OCNF）热触发凝胶化的新机制。我们证明了一种结合流变学、小角度x射线散射（SAXS）和饱和转移差核磁共振（STD核磁共振）实验的协同方法，可以在不同长度尺度上详细表征凝胶化。神学研究证明，OCNF分散体在加热时经历固体样行为的增加，这与使用SAXS测量的纤维间相互作用增强有关。相互作用导致纤维重叠增加，并增加了STD核磁共振监测的封闭水分子的数量。相比之下，阳离子纤维素纳米原纤维（由纤维素与三甲基缩水甘油三酯氯化铵反应产生）被发现对热无反应。(C) 2018年作者。Elsevier Inc.出版。
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 Theological 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. (C) 2018 The Authors. Published by Elsevier Inc.