Highly selective adsorption resins .1. Preparation of chitosan derivatives containing 2-pyridylmethyl, 2-thienylmethyl, and 3-(methylthio)propyl groups and their selective adsorption of precious metals
Highly selective adsorption resins .1. Preparation of chitosan derivatives containing 2-pyridylmethyl, 2-thienylmethyl, and 3-(methylthio)propyl groups and their selective adsorption of precious metals
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DOI：
10.1246/bcsj.69.1255
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发表时间：
1996-05-01
影响因子：
4
通讯作者：
Hirakawa, H
中科院分区：
文献类型：
--
作者：
Baba, Y;Kawano, Y;Hirakawa, H
新合成了交联N-(2-吡啶基甲基)壳聚糖、N-(2-噻吩基甲基)壳聚糖和N-[3-(甲硫基)丙基]壳聚糖。壳聚糖活性吸附位点的氨基在被 2-(氯甲基)环氧乙烷交联之前通过席夫碱形成得到保护。通过用硼氢化钠还原席夫碱的亚胺部分获得最终的壳聚糖衍生物。使用间歇方法从含有盐酸的溶液中检测金属离子在壳聚糖衍生物上的吸附行为。这些壳聚糖衍生物在盐酸中对金 (III)、钯 (II) 和铂 (IV) 表现出比贱金属高的选择性和优异的负载能力。为了阐明壳聚糖衍生物上钯(II)的吸附形态，考察了氯离子浓度对钯(II)吸附分配比的影响。发现这些壳聚糖衍生物对钯(TI)的吸附能力比交联的原始壳聚糖大约2.5-3倍。通过用硫脲水溶液单次分批处理，钯(II)的解吸附达到70%的程度。
Crosslinked N-(2-pyridylmethyl)chitosan, N-(2-thienylmethyl)chitosan, and N-[3-(methylthio)propyl]chitosan were newly synthesized. The amino group of the active adsorption site of chitosan was protected by Schiff's base formation prior to being crosslinked by 2-(chloromethyl)oxirane. The final chitosan derivatives were obtained by reducing the imine moiety of the Schiff's bases with sodium borohydride. The adsorption behavior of metal ions on the chitosan derivatives was examined from a solution containing hydrochloric acid using a batchwise method. These chitosan derivatives exhibited high selectivities and excellent loading capacities for gold(III), palladium(II), and platinum(IV) over base metals in hydrochloric acid. In order to elucidate the adsorption species of palladium(II) on the chitosan derivatives, the effect of the chloride ion concentration on the distribution ratio in the adsorption of palladium(II) was examined. The adsorption capacities of these chitosan derivatives for palladium(TI) were found to be about 2.5-3 times greater than that of the cross-linked original chitosan. The desorption of palladium(II) was performed to an extent of 70% by a single batchwise treatment with aqueous thiourea solution.