FTIR研究非完全脱乙酰甲壳质对金属离子的吸附机理

STUDIES OF ADSORPTION MECHANISM OF METAL ION ON PART-DEACETYLATION CHITIN BY FTIR SPECTROSCOPY

以傅立叶交换红外光谱(FTIR)法研究了非完全脱乙酰甲壳质(NCTS)与Cu~ (2+),Ni^(2+),Co^(1+),Zn^(2+),Cd(2+),Hg^(2+),Ag^+,Pb^(2+)等八种金属离子形成的配合物的结构特征,并对各配合物在4000—400cm^(-1)范围内的主要吸收带作了经验归属.研究结果表明,在NCTS的金属离子配合物中,除—NH_2,—OH参予了配位外,羰基((?)C=O)和酰胺基(—CONH—)亦在不同程度上参予了配位;NCTS对Hg^(2+),Ag^+的吸附过程中存在着明显的氧化还原现象,Hg^(2+),Ag^+,分别被还原为Hg_2^(2+)和Ag^0,而NCTS分子中的—CH_2OH有可能被氧化成—COOH.

The structures of complexes of part-deacetylation chitin (NCTS) with Cu2+ ,Ni2+ , Co2+, Zn2+, Cd2+, Hg2+, Ag+and Pb2+ were studied by FTIR spectroscopy, and the major IR bands in 4000-400cm-1 were assigned, respectively. The results showed not only -NH2 and -OH could chelate metal ion but also -CO- and -CONH- did to a certain extent in the above mentioned complexes. There is oxidation-reduction in the adsorption of Hg2+ and Ag+ on NCTS and Hg2- and Ag+ were reduced to Hg22+ and Ag0 respectively, and the -CH2 OH in the molecule of NCTS was oxidized to -COOH.