Experimental study of microchannel flow for non-Newtonian fluid in the presence of salt

• Hydraulic characteristics of electrolyte-added non-Newtonian fluid flow in microchannels are experimentally studied.
• The electrolytes affect the hydraulic characteristics of anion polyacrylamide solution flow in microchannels.
• The nonionic polyacrylamide solution is hardly affected by the electrolytes.

Hydraulic characteristics of non-Newtonian fluid flow in smooth fused silica microtubes with diameter ranging from 75 to 320 μm are experimentally investigated. Hydraulic characteristics of deionized water (DI water), anion polyacrylamide (APAM) and nonionic polyacrylamide (NPAM) solution with sodium chloride (NaCl), calcium chloride (CaCl2) and magnesium chloride (MgCl2) over a wide range of flow rates are presented. The results show that the three types of electrolytes have important effect on the hydraulic characteristics of APAM solution flow in microchannels. However, the NPAM solution is hardly affected by the present electrolytes with different concentrations. Similar to the NPAM solution, no obvious electrolyte-effect is found for the DI water flow in smooth fused silica microchannels, and the experimentally obtained flow rate and friction factor agree well with conventional theory predictions.