饱和锌的粘土矿物吸附半胱氨酸的机理

Adsorption Mechanism of Cysteine on Zinc-saturated Clay Mineral

用红外光谱、X射线衍射(XRD)和热分析研究了饱和过渡金属锌的粘土矿物吸附半胱氨酸的机理 ;XRD结果显示吸附了半胱氨酸后的粘土矿物的d(001)方向的距离明显增大 ,说明被吸附的半胱氨酸进入了粘土的层状结构之中 ;饱和了锌的粘土矿物吸附半胱氨酸有两种方式 ,其一为弱相互作用,另一种强相互作用;后一种方式吸附的半胱氨酸与粘土的过渡金属之间形成了配合结构 ,结合力比较强 ,在热作用下 ,它们一直到395℃左右才分解 ;强相互作用吸附的半胱氨酸主要是以去质子的两性离子和阴离子形式存在于粘土矿物上 ,与过渡金属形成螯合的六元环结构。

Adsorption mechanism of cysteine on clay mineral saturated by transition metal of zinc was studied by X_ ray diffraction, thermoanalysis and infrared spectrometry. The distance of d(001) in clay mineral adsorbing cysteine increased evidently, this indicated that cysteine entered into interlayers of clay mineral. The zinc _ saturated clay mineral adsorbed cysteine with two modes: weak interaction and strong interaction. The later mode led to formation of complexes between interlayer zinc cation and cysteie, which did not break up until they were heated to about 395 ℃. The cysteine in the clay mineral existed in the forms of zwitterion and anion, the O and S in it chelated zinc cation to form configuration of hexatomic ring.