Numerical study on the Ionic current characteristic in nanopores

• Main Authors: Bao-gan Chung, 鐘寶灨
• Other Authors: 簡瑞與
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/92683075872942684873

碩士 === 國立中興大學 === 機械工程學系所 === 98 === In this study, the ionic transport characteristics through a cylindrical nanochannel with charged entrance and exit and linearly varied surafce charge density along the nanochannel wall is numerically investigated. The ends of the nanochannel was connected with the microchanels which were regarded as the reservoirs. The Nernst-Planck equation that governed the ionic distribution was solved along with the Poission equation and Navier-Stokes equations. Based on the nuemrical resulted of current-voltage curves obtained, it was found that the charge entrance can enhance the concentraion polarization in the anodic side of the nanochannel as compared with the uncharged entrance case. As comapred with conventional conducting membrane, no limiting current regime can be obserevd when the chraged entrance is included. Instead the current varies quradratically with the applied voltage. Current rectification can be observed for nanochannel with and without charged entrance and exit when channel wall has linearly varied surface charge density. The numerical results indicated that the current rectification factor is higher for the nanochannel with charged entrance than that without charged entrance. The current rectification factor also found to increase with decrease of bulk concentration and increases of the surface charge density magnitude, slope, and charged entrance size.