| 摘要: | 本實驗利用懸浮聚合與逆懸浮聚合反應將強螯合劑Pentaehtylenehexamine(PEHA)固定於共聚合物上，合成具強螯合能力之高分子螯合劑，並且利用其卓越的螯合能力螯合吸附處理含乙二胺四乙酸(EDTA)之錯合物廢水。更進一步的，利用固態核磁共振光譜儀(S-NMR)、元素分析儀(EA)、掃瞄式電子顯微鏡(SEM)等儀器測量螯合型高分子之結構組成與特性。由傅利葉紅外線吸收光譜圖中發現，高分子金屬錯合物在3370 cm-1之N-H 伸展吸收峰有分子內氫鍵之影響，並且在1385 cm-1形成三級胺。在高分子螯合劑吸附銅離子後，形成共價鍵之作用力較氫鍵強，故N-H 伸展吸收峰往高頻率的方向偏移。若在含EDTA配位基與銅金屬離子所形成非常穩定的錯合物溶液中，加入含有強螯合能力的高分子螯合劑時，會將穩定常數較小的的錯合物分解，高分子螯合劑與金屬離子形成高分子金屬錯合物。另外，利用高分子螯合劑在不同的pH值下，與銅離子和Cu-EDTA進行競爭吸附。可計算出高分子螯合劑與銅離子保有1018.75之高穩定常數足以與EDTA競爭。從X-ray繞射分析(XRD)、能量散佈光譜儀(EDS)及離子層析儀(IC)結果中均發現高分子螯合劑不但可吸附陽離子的重金屬離子，也吸附水溶液中的陰離子Cl-、SO42-等。高分子金屬錯合物吸附氯鹽和硫酸鹽之最高去除率可分別高逹93% 和97%。有趣地是，本研究由Ｘ光電子譜儀(ESCA)的結果發現，高分子螯合劑吸附的銅離子部分轉化成銅原子Cu(0)。顯然本文所合成的高分子螯合劑不但可做為金屬離子的吸附劑，也可作為金屬離子還原用的高分子還原劑。
The strong chelating functional group, pentaethylenehexamine, was immobilized onto copolymer to obtain chelating copolymers via suspension and inversion suspension polymerization in this study. The characteristic of chelating copolymers was measured by using Solid-Nuclear Magnetic Resonance spectroscopy(S-NMR), Elemental analysis (EA), and Scanning Electron Microscope (SEM), respectively. FT-IR spectra of the macromolecule metal complexes display the hydrogen bond within chelating polymer affected the adsorption peak of stretch N-H at 3370 cm-1, and form triamine at 1385 cm-1. After chelating copolymers adsorbing cupric ions, coordinate bonding was formed by cupric ions with chelating copolymers, and made the adsorption peak of stretch N-H to shift to higher frequency. Furthermore, the mechanism of metal complex adsorption on chelating copolymer was that the stronger chelating copolymer will force the bonding of the metal complex to decompose and withdraw the cupric ion into chelating polymer according to the FTIR result. In addition, most of the metal ions showed adsorption capacity increased with the increase of pH of the solution. The stability constant of Cu-chelating copolymer was as high as 1018.75, and it is enough to compete with EDTA. Interesting, the chelating copolymers not only chelated metal cation, but also adsorbed anion from result of X-ray diffraction (XRD), Energy Dispersive Spectrometer (EDS) and Ion chromatography (IC). Chlorate and sulfate could be removed more than 93% and 97% from the solution, respectively. The part of cupric ions adsorbed inside chelated group was reduced to copper(0) and/or copper(I) from result of X-ray photoelectron spectroscopy (ESCA). This results shown that the chelating copolymer not only can as a metal chelating adsorbent, but also as a molecular reducer. This technology can be employed to many applications, such as nanocomposites, etc. |
