Detection of Metal Ions by Cholesteric Liquid Crystal Mixtures with Ethylene Oxide Probes

• Main Authors: Chueh, Tung, 闕彤
• Other Authors: Lin,Hong-Cheu
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/19189335898963386959

碩士 === 國立交通大學 === 材料科學與工程學系所 === 101 === 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.