Surface carboxylation of porous regenerated cellulose beads by 4-acetamide-TEMPO/NaClO/NaClO2 system
Surface carboxylation of porous regenerated cellulose beads by 4-acetamide-TEMPO/NaClO/NaClO2 system
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DOI：
10.1007/s10570-009-9296-y
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发表时间：
2009-10-01
期刊：
影响因子：
5.7
通讯作者：
Isogai, Akira
中科院分区：
文献类型：
--
作者：
Hirota, Masayuki;Tamura, Naoyuki;Isogai, Akira
将市售再生珠状纤维素悬浮于pH 4.8的水中，并用用作主氧化剂的NaClO 2和催化量的NaClO和4-乙酰胺基-2，2，6，6-四甲基哌啶基-1-氧基自由基进行氧化。通过将C6伯羟基氧化为羧酸盐，珠子中形成的羧酸根基团高达1.87 mmol/g，而没有显着的重量损失或形态变化。的球形形状，高度多孔的表面结构组成的纳米尺寸的原纤维，和纤维素II的晶体结构的原始珠主要保持由氧化，表明形成的羧酸基团主要存在于原纤维表面上。TEMPO-氧化纤维素珠的阳离子交换行为进行了比较，羧甲基化纤维素珠，表明前者是特征和上级优于后者的金属离子和阳离子聚合物的吸附。特别是TEMPO氧化纤维素珠对铅离子和高分子量阳离子聚合物具有高吸附性能。
A commercial regenerated bead cellulose was suspended in water at pH 4.8, and oxidized with NaClO2 used as a primary oxidant and catalytic amounts of NaClO and 4-acetamide-2,2,6,6-tetramethylpiperidinyl-1-oxyl radical. Carboxylate groups were formed up to 1.87 mmol/g in the beads by the oxidation of C6 primary hydroxyls to carboxylates without significant weight losses or morphological changes. The spherical shapes, highly porous surface structures consisting of nano-sized fibrils, and the cellulose II crystal structure of the original beads were mostly maintained by the oxidation, indicating that the carboxylate groups formed are predominantly present on the fibril surfaces. Cation-exchange behavior of the TEMPO-oxidized cellulose beads was compared with carboxymethylated cellulose beads, showing that the former was characteristic and superior to the latter in terms of adsorption of metal ions and cationic polymers. Especially, the TEMPO-oxidized cellulose beads had high adsorption behavior of lead ion and high-molecular-weight cationic polymers.