Cellulose nanofibers prepared by TEMPO-mediated oxidation of native cellulose
Cellulose nanofibers prepared by TEMPO-mediated oxidation of native cellulose
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DOI：
10.1021/bm0703970
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发表时间：
2007-08-01
影响因子：
6.2
通讯作者：
Isogai, Akira
中科院分区：
文献类型：
--
作者：
Saito, Tsuguyuki;Kimura, Satoshi;Isogai, Akira
采用2，2，6，6-四甲基哌啶-1-氧自由基（克里思）介导的体系氧化从未干燥和干燥过的硬木纤维素，并通过机械处理氧化纤维素/水浆料制备分散在水中的高度结晶和个性化的纤维素纳米纤维。当由纤维素的伯羟基形成的羧酸盐含量达到约1.5mmol/g时，氧化的纤维素/水浆料通过机械处理大部分转化为透明且高粘度的分散体。透射电子显微镜观察显示分散体由宽度为3-4 nm和长度为几微米的个体化纤维素纳米纤维组成。对于制备分散体，未干燥和干燥一次的纤维素之间没有发现内在差异，只要TEMPO氧化的纤维素中的羧酸根含量达到约1.5 mmol/g。在机械处理过程中的分散体的粘度的变化对应于那些在水中的纤维素纳米纤维的分散状态。
Never-dried and once-dried hardwood celluloses were oxidized by a 2,2,6,6-tetramethylpiperidine-l-oxyl radical (TEMPO)-mediated system, and highly crystalline and individualized cellulose nanofibers, dispersed in water, were prepared by mechanical treatment of the oxidized cellulose/water slurries. When carboxylate contents formed from the primary hydroxyl groups of the celluloses reached approximately 1.5 mmol/g, the oxidized cellulose/water slurries were mostly converted to transparent and highly viscous dispersions by mechanical treatment. Transmission electron microscopic observation showed that the dispersions consisted of individualized cellulose nanofibers 3-4 nm in width and a few microns in length. No intrinsic differences between never-dried and once-dried celluloses were found for preparing the dispersion, as long as carboxylate contents in the TEMPO-oxidized celluloses reached approximately 1.5 mmol/g. Changes in viscosity of the dispersions during the mechanical treatment corresponded with those in the dispersed states of the cellulose nanofibers in water.