中孔洞分子篩表面修飾及其重金屬萃取應用

Surface modification of mesoporous molecular sieves and its applications

黃裕髣(Yu-Fang Huang)

指導教授 ： 鄭吉豐

中原大學/理學院/化學研究所/碩士(2003年)

https://doi.org/10.6840/cycu200300576

摘要

摘要

本論文旨在研究，如何對中孔洞分子篩進行雙重表面修飾改質。並探討中孔洞分子篩雙重表面修飾的反應控制以及修飾後產物的進一步應用。
在管壁修飾方面，首先利用末端含胺官能基的矽烷對中孔洞分子篩進行初步表面修飾，使其帶有具反應活性的胺基並利用基材上的胺基與活性高的酸酐進行第二階段有機改質反應。實驗鑑定結果顯示經第二階段有機改質後，中孔洞分子篩被賦予更多有機材料的特性，這有利於其他方面的應用。就本實驗來說成功利用中孔洞分子篩合成出固態酸及具萃取金屬離子能力的吸附材。
管壁修飾的應用方面，含螯合物EDTA的中孔洞分子篩MCM-41(MCM-EDTA)對金屬離子吸附有明顯的效果。吸附實驗結果顯示MCM-EDTA隨著溶液pH值的增加，對金屬離子萃取的能力越強，且不論是在單一金屬離子環境或是混合金屬離子環境下，當溶液pH值大於1時，MCM-EDTA皆可有效清除溶液中的金屬離子，除了錳、砷(非)金屬離子以外。在單一金屬離子環境下，金屬離子皆被萃取九成以上；而混合金屬離子環境，吸附材對金屬離子的萃取穩定性排序為Cu+2＞Pb+2＞Ag+1＞Fe+3＞Ni+2＞Cd+2》Zn+2》As+5≒Mn+2。且MCM-EDTA在短短時間內對金屬離子在吸附力、吸附量方面就有不錯的表現，顯現其捕捉金屬離子的效率。再者增加吸附材MCM-EDTA重量，可提升吸附材萃取金屬離子的能力。

關鍵字

中孔洞分子篩

並列摘要

Abstract

Surface modification of mesoporous silica gives enormous stimulus to the field of nanostructured organic-inorganic composite materials, opening new horizons for selective organic transformation and material science. By the Surface modification of mesoporous silica MCM-41, inorganic adsorbents modified with EDTA ligands were successfully synthesized. At first, MCM-41 was organofunctionalized by 3-aminopropyltrimethoxysilane (APTMS) on the surface of its nanochannels. EDTA was used to embedded in the nanochannels of mesoporous materials were prepared by the chemical binding of anhydride to the amino-modified surface of MCM-41.
The extraction of transition metals has been investigated using MCM-41 adsorbents modified with ethylenediaminetetraacetic acid (EDTA) as chelating ligands. The metal ions in aqueous solution were coordinated successfully by the ligands on the surface of the adsorbents under moderate conditions. The extractability of the adsorbents was efficient when increasing pH value in metal ions aqueous solution. In general, most metal ions in aqueous solution can be extracted above 90% when pH＞1. MCM-41 modified with EDTA (MCM-EDTA) was shown to be the most effective adsorbent for the extraction of metal ions and to form specific metal-EDTA complexes, with stability constants lying in the order Cu+2＞Pb+2＞Ag+1＞Fe+3＞Ni+2＞Cd+2》Zn+2》As+5≒Mn+2. In addition, MCM-EDTA merely needs a very short time to anchor almost metal ions and increasing weight of the adsorbents can enhance amount of adsorptive metal ions.

並列關鍵字

mesoporous molecular sieves

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