کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
825733 1470069 2007 20 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Electro-osmotic transport in charged cylindrical micro- and nano-channels
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی (عمومی)
پیش نمایش صفحه اول مقاله
Electro-osmotic transport in charged cylindrical micro- and nano-channels
چکیده انگلیسی

Present paper deals with the electro-osmotic flow in a infinitely extended cylindrical micro- and nano-channel. The channel height is considered to be much less than the channel length. We consider a mixture of water or another neutral solvent and a salt compound such as sodium chloride for which the ionic species are entirely dissociated. We have developed a two-dimensional numerical model to analyze the flow characteristics and concentration distributions of a electro-osmotic flow without using the Debye–Hückel approximation. The governing system of equations consist of the mole fractions of ions, the potential and the fluid flow equations. Results are produced for the case, where the channel height is much greater than the width of the electric double layer (EDL) (micro-channel) and for the case where the channel height is of the order of the width of the EDL (nano-channel). For various values of mole fraction, we studied the electro-osmotic flow profiles and the potential distribution along the channel at different channel heights. In this case of steady flow the velocity field and the potential are identical. The electro-osmotic flow produces a uniform ‘plug profile’ at channel heights greater than 20 nm, which results in reduced sample species dispersion as compared to the velocity gradients associated with the pressure driven flows. Asymptotic solutions are obtained when the flow in a micro-channel is considered.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Engineering Science - Volume 45, Issue 1, January 2007, Pages 55–74
نویسندگان
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