Abstract—Counterion condensation phenomenon of a highly charged polyelectrolyte is directly related to DNA (DeoxyriboNucleic Acid) condensation and RNA (RiboNucleic Acid) folding, which are research topics of vital interest in areas like biological and medical sciences as well as electrokinetic separations. With the advances of the modern micro/nanofabrication technology, practical applications are normally conducted in corresponding micro/nanochannels. As a result, a fundamental understanding of the counterion condensation phenomenon within a micro/nanochannel is crucial for successful operations utilizing it. We provide a theoretical analysis here with the polyelectrolye modelled as a charged porous sphere, and the full nonlinear Poisson equation is adopted to describe the interaction between the counterions in the suspending electrolyte solution and the backbone macroion of the polyelectrolyte itself. The solution is obtained numerically with a pseudo-spectral method based on Chebyshev polynomials. The degree of counterion condensation is expressed as a function of various parameters of interest, such as the charge condition of the polyelectrolyte, the ratio of the particle to pore radii, and the ionic strength of the suspending electrolyte solution. Results presented here provide useful information relevant in various practical applications such as biosensors, DNA stretching, and gene delivery.
Index Terms—Boundary confinement effect, counterion condensation, nanostructure, polyelectrolyte.
C. H. Huang was with the Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan. He is now with Taiwan Semiconductor Manufacturing Company (e-mail: hsuanhzb@tsmc.com).
Y. F. Lee and E. Lee are with the Department of Chemical Engineering, National Taiwan University, Taipei, Taiwan (e-mail: r03524038@ntu.edu.tw, ericlee@ntu.edu.tw).
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Cite: Cheng-Hsuan Huang, Yu-Fan Lee, and Eric Lee, "Counterion Condensation of a Polyelectrolyte within a Micro/Nanochannel," International Journal of Chemical Engineering and Applications vol. 7, no. 2, pp. 96-101, 2016.
