Influences of Salt Valence and Geometric Shape of a Nanochannel on Its Rectification Behavior

• Main Authors: Yu-Min Chen, 陳俞閔
• Other Authors: Jyh-Ping Hsu
• Format: Others
• Language: en_US
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/mn45tg

碩士 === 國立臺灣大學 === 化學工程學研究所 === 106 === The overlapping of electric double layer in a nano-scaled system is usually significant, rendering it having profound and interesting electrokinetic phenomena, such as ion concentration polarization (ICP) and ion current rectification (ICR), and thus fabrication of nanodevices becomes a trend of nanotechnology. In Chapter 1, by taking account of various electrolyte solution LaCl3、CaCl2、KCl、KNO3, and K2SO4, a thorough numerical simulation is conducted to illustrate the influence of asymmetry of various ionic valence ratio on the ICR behavior in a conical nanochannel. We show that the electrokinetic phenomena depend highly on ionic strength and ion diffusivity. The qualitative behavior of the ion current rectification of a positively charged conical nanochannel is similar to that of a negatively charged one.In Chapter 2, we consider a bioinspired cigar-shaped nanochannel where its surface is pH-regulated, and has zwitterionic groups. The influences of the solution pH, the bulk concentration, the base opening radii, and the nanochannel shape on the associated ICR behavior and ionic selectivity are examined, focusing on discussing the underlying mechanisms in detail. We show that the best nanochannel performance can be achieved by adjusting the base orifice radii and surface curvature appropriately. In addition to proposing underlying mechanisms for the phenomena observed, the results gathered in this study also provide necessary information for designing relevant devices.