بررسي خصوصيات ساختاري جريان الكترواسموتيك شكل گرفته در يك نانوكانال به روش ديناميك مولكولي

در اين مقاله جريان الكترواسموتيك در يك محلول الكتروليت و در مجاورت دو ديواره باردار موازي شبيه سازي شده است. نتايج شبيه سازي نشان مي دهند كه جريان الكترواسموتيك به صورت يك جريانيكنواخت با شرط عدم لغزش بر روي ديواره ها عمل مي كند،يعني سرعت جريان از مقدار صفر بر روي دو ديواره شروع شده و در ناحيه دوگانه الكتريكي با شيب نسبتاً زيادي افزايش مي يابد تا به يك مقدار ثابت در توده سيال برسد. در پژوهش حاضر، نمك هاي تك ظرفيتي كلريد سديم و كلريد پتاسيم و نمك هاي دو و سه ظرفيتي كلريد منيزيم و كلريد لانتانوم به صورت جداگانه به محلول الكتروليت اضافه شده اند. بابررسي نتايج به دست آمده درمي يابيم كه در نمك هاي تك ظرفيتي جريان قوي تري در توده سيال ايجاد مي شود. اين نتايج نشان مي دهند كه در محلول هاي حاوي دو نمك چندظرفيتي مورد بررسي، بلافاصله پس از ناحيه دوگانه الكتريكي افت شديدي در سرعت جريان ايجاد مي شود. همچنين بررسي تغييرات چگالي بار الكتريكي در نزديكي ديواره براي هر كدام از اين محلول هانشانمي دهد كه كه با افزايش ظرفيت كاتيون هاي نمك، ميزان بارالكتريكي جذب شده در زيرلايه فشرده افزايش مي يابد و همين امر سبب كاهش چگالي بار الكتريكي در زيرلايه ديفيوز مي شود. Electro-osmotic flow of an aqueous solution between two parallel silicon walls was studied by molecular dynamics simulation. Effects of the electrolyte solution on flow properties were examined by varying type of the salt. To achieve this goal, two monovalent salts (NaCl&KCl), a divalent salt (MgCl2), and a trivalent salt (LaCl3) were simulated. The unique point of this study is that the flow behaviour is analyzed by investigating the changes made in the electrical double layer (EDL) properties. It was found that flow velocity rises from zero to a larger value in the EDL, while it remains constant in the bulk flow. Results showed that the electro-osmotic flow formed by a mono-valent salt is stronger than that formed by multivalent salts. Also it was observed that the flow velocity suddenly decreases, immediately after the EDLʹs boundaries in the solutions containing multivalent salts. By increasing the valence of the salt, the number of cations attracted in the stern layer increases and so the ability of the EDL to form the electro-osmotic flow decreases. In addition, it was observed that physical properties of the driving ions like the ionic diameter affect on the electro-osmotic flow properties.

Electro-osmotic flow of an aqueous solution between two parallel silicon walls was studied by molecular dynamics simulation. Effects of the electrolyte solution on flow properties were examined by varying type of the salt. To achieve this goal, two monovalent salts (NaCl&KCl), a divalent salt (MgCl2), and a trivalent salt (LaCl3) were simulated. The unique point of this study is that the flow behaviour is analyzed by investigating the changes made in the electrical double layer (EDL) properties. It was found that flow velocity rises from zero to a larger value in the EDL, while it remains constant in the bulk flow. Results showed that the electro-osmotic flow formed by a mono-valent salt is stronger than that formed by multivalent salts. Also it was observed that the flow velocity suddenly decreases, immediately after the EDLʹs boundaries in the solutions containing multivalent salts. By increasing the valence of the salt, the number of cations attracted in the stern layer increases and so the ability of the EDL to form the electro-osmotic flow decreases. In addition, it was observed that physical properties of the driving ions like the ionic diameter affect on the electro-osmotic flow properties