TEMPO-mediated oxidation of β-chitin to prepare individual nanofibrils
TEMPO-mediated oxidation of β-chitin to prepare individual nanofibrils
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DOI：
10.1016/j.carbpol.2009.03.008
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发表时间：
2009-07-19
影响因子：
11.2
通讯作者：
Isogai, Akira
中科院分区：
文献类型：
--
作者：
Fan, Yimin;Saito, Tsuguyuki;Isogai, Akira
采用克里思（2，2，6，6-四甲基哌啶-1-氧自由基）氧化法制备了甲壳素纳米纤维。通过控制在氧化中用作主要氧化剂的NaClO的添加水平，以各种比例获得TEMPO氧化的β-几丁质的水不溶性级分。TEMPO-氧化的管虫β-几丁质的水不溶性级分，当它们具有0.18-0.25 mmol/g的羧酸根基团时，通过在水中崩解成功地转化为高粘性和半透明的凝胶。凝胶主要由宽度为20-50 nm且长度为至少几微米的单个纳米原纤维组成。另一方面，TEMPO-氧化的鱿鱼围栏β-几丁质的水不溶性级分可以在所使用的任何氧化或崩解条件下转化为既不透明也不半透明的分散体。当使用足够量的NaClO时，通过将所有C6伯羟基氧化成羧酸酯基团，两种β-几丁质都被完全氧化成相应的水溶性多糖醛酸。(C)2009爱思唯尔有限公司保留所有权利。
TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation was applied to beta-chitins, originating from tubeworm and squid pen, to prepare chitin nanofibrils. Water-insoluble fractions of the TEMPO-oxidized beta-chitins were obtained in various ratios by controlling the addition level of NaClO used as the primary oxidant in the oxidation. The water-insoluble fractions of the TEMPO-oxidized tubeworm beta-chitins, when they had carboxylate groups of 0.18-0.25 mmol/g, were successfully converted to highly viscous and translucent gels by disintegration in water. The gels consisted of mostly individual nanofibrils 20-50 nm in width and at least several microns in length. On the other hand, the water-insoluble fractions of the TEMPO-oxidized squid pen beta-chitins could be transformed to neither transparent nor translucent dispersions under any oxidation or disintegration conditions used. When sufficient amounts of NaClO were used, both beta-chitins were completely oxidized to the corresponding water-soluble polyuronic acids by oxidation of all C6 primary hydroxyls to carboxylate groups. (C) 2009 Elsevier Ltd. All rights reserved.