INTEC (Universidad Nacional del Litoral-CONICET), Güemes 3450, 3000 Santa Fe, Argentina.
J Colloid Interface Sci. 2010 Sep 1;349(1):446-8. doi: 10.1016/j.jcis.2010.05.083. Epub 2010 May 31.
Electrokinetic energy conversion in microfluidic systems is a subject of intense research at present, where the main objective is to improve the thermodynamic efficiency of the process. As a novel strategy to the problem, this work focuses on the fluid dynamic properties of the working fluid. It is shown that polymer solutions with wall depletion can substantially increase the conversion efficiency in comparison to simple electrolytes under the same operating conditions. The effect is given by a reduction of the hydrodynamic conductance, while the streaming current is unaltered. It is also found that the maximum efficiency of electrokinetic power generation differs from that of electroosmotic pumping, in contrast to the case of simple electrolytes. This is due to the non-Newtonian character of polymeric fluids, which leads to nonlinear electrokinetic relations.
目前，微流控系统中的电动能量转换是一个研究热点，主要目标是提高该过程的热力学效率。作为解决该问题的一种新策略，本工作侧重于工作流体的流体动力学特性。结果表明，与相同操作条件下的简单电解质相比，具有壁面耗尽的聚合物溶液可以大大提高转换效率。这种效果是由流体动力学电导的降低引起的，而流动电流保持不变。还发现，与简单电解质的情况相反，电动发电的最大效率不同于电渗泵的最大效率。这是由于聚合物流体的非牛顿特性导致了非线性电动关系。
