含聚環氧乙烷膽固醇相液晶混合物於金屬離子之檢測

Abstract

本論文合成出一系列可錯合金屬離子的分子，由聚環氧乙烷長鏈段錯合金屬離子，並利用FT-IR鑑定是否錯合金屬離子，此化學感測器藉由錯合金屬離子的分子影響膽固醇液晶相的螺距長短而使顏色產生改變，成功的由含有聚環氧乙烷的分子混摻室溫型液晶與chiral dopant偵測多種金屬離子，比較不同長度的聚環氧乙烷對不同金屬離子的錯合後的差異。大部分偵測金屬離子的液晶混合物變化為綠色變為藍色，而最佳應用於感測器的液晶混合物經由肉眼觀察原本的綠色在混入鐵離子(Fe3+)後轉變為紅色，在混入鉀離子(K+)後依然為綠色。 此化學感測器可感測至10-6 mole的金屬離子，且顯色快速亦可直接用肉眼觀察，不須藉由儀器的測量。

We synthesize a series of compounds which use polyethylene oxide groups to complex metal ions. We utilize FT-IR to identify whether the compounds can complex metal ions or not. The chemosensors are used to detect metal ions by changing the pitch of cholesteric liquid crystal phases, so that we can see the colors of cholesteric liquid crystal phase change by eyes. We successfully detect several kinds of metal ions by cholesteric liquid crystal mixtures which contain polyethylene oxide probes, liquid crystals and chiral dopants. Moreover, we compare different lengths of polyethylene oxide groups to detect different metal ions. The chemosensor of liquid crystal mixtures is green at first, after doping most kinds of metal ions, it changes to blue.The different change is using the chemosensors to detects iron(III) ions and potassium ions. After doping iron(III) ions, it changes to red, and after doping potassium, it remains green ions The limit of detection is 10-6 mole of metal ions.