丝素蛋白吸附金属离子的性能及其机理的研究

Study of the Adsorption and the Mechanism of Metal Ions by Fibroin

丝素蛋白是蚕丝的主要组成部分,具有较好的吸湿性、透气性、吸附性等。而现今人类生活环境中存在较多的有害金属离子,因此拓展丝素蛋白吸附金属离子的用途具有重要的意义。本文在前期研究已证实丝素蛋白具有较好的吸附重金属离子能力的基础上,进一步测定分析了不同状态下的丝素蛋白(溶液状、凝胶状、粉末状)对金属离子(以锌为例)的吸附作用,探讨了丝素蛋白二级结构的变化,阐明了丝素蛋白吸附金属离子的机理。结果显示:丝素蛋白吸附锌离子时,氢元素与氧元素参与了其反应,而氮元素也可能参与了反应,丝素蛋白肽链上的-OH、-CO-NH-以及-NH2与Zn2+通过配位键形成了配合物;且丝素蛋白β-折叠增加而无规卷曲减少,丝素蛋白与Zn2+形成的配合物具有更稳定配位结构;同时p H对该配位反应过程也存在一定的影响。

Silk fibroin is the main component of the silk, with excellent properties like moisture absorption, air permeability and adsorption. Harmful metal ions in environment have an adverse influence on human life. Thus, it is of great importance that expanding the applications of silk fibroin into environment protection by taking advantage of its excellent properties. As my previous work indicated, silk fibroin has abilities to adsorb heavy metal ions such as copper,zinc, and lead. This study explored the adsorption mechanism of zinc ions onto RSF in different states（aqueous solution,gel, powder）, and analyzed the conformational changes of RSF. It turned out： oxygen and hydrogen in RSF reacted with zinc ions, while nitrogen might be involved in the reaction, which means the- OH,- CO- NH- and- NH2 of RSF coordinate with Zn2＋; the content of β-sheet in RSF was increased while the random coil decreased during the reaction,which makes the RSF become more stable; p H was related to the reaction as well.