Continuous monitoring of pH level in flow aqueous system by using liquid crystal-based sensor device
學年 106
學期 2
出版(發表)日期 2018-06-01
作品名稱 Continuous monitoring of pH level in flow aqueous system by using liquid crystal-based sensor device
作品名稱(其他語言)
著者 Wei-Long Chen; Tsung Yang Ho; Jhih-Wei Huang; Chih-Hsin Chen
單位
出版者
著錄名稱、卷期、頁數 Microchemical Journal 139, p.339–346
摘要 In this work, we report a liquid crystal (LC)-based sensor to determine pH level of aqueous solutions. This sensor was fabricated by filling the LCs doped with a pH-sensitive molecule into a cupper grid on a glass substrate. Theoretically, the dopants are neutral and disperse freely in the LCs. When the sensor was immersed in the aqueous solution, the increases of pH can lead to the dissociation of the dopants, allowing them to align at the LC/aqueous interface. This phenomenon causes the reorientation of the LC molecules and therefore a bright-to-dark transition of the LC image was observed simply through naked-eye. In our research, we found that the critical pH value for the optical transition of LC sensors can be adjusted from 6.8 to 8.2 through the selection of dopants, while it can be adjusted from 6.2 to 7.0 through the selection of dopant concentrations. By arranging four individual sensors in a device with inlet and out channels, we demonstrated that the pH level of an aqueous flow system can be determined by the number of bright LC sensors shown in the device. Based on this strategy, we developed a device to monitor the pH safety level for drinking water ranging from pH 6.5 to 8.5. This device demonstrated fast response (~1 s), good stability, reversibility and its capability to measure the pH change in tap water and pond water, which make it suitable for real-time and continuous monitoring the pH change in various flow aqueous systems.
關鍵字 Liquid crystal-based sensor;Reversible pH sensor;Continuous monitoring of pH in flow system;pH monitoring for drinking water;Naked-eye detection
語言 en
ISSN 0026-265X
期刊性質 國外
收錄於 SCI
產學合作
通訊作者 Chih-Hsin Chen
審稿制度
國別 NLD
公開徵稿
出版型式 ,電子版,紙本
相關連結

機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/113428 )