Determination of the surface charge density of a nanoporous silicon membrane during electroosmotic pumping

Details

Supervisors

Francis, Laurent

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil en chimie et science des matériaux, à finalité spécialisée

Abstract

The surface charge density of a porous membrane plays a crucial role in the functioning of an electroosmotic pump. This parameter allows the determination of the flow performance of the pump. This study is dedicated to determining this crucial value for membranes of diverse materials and geometrical characteristics. This determination is achieved through a combination of experimental, analytical and numerical methods, using the Comsol Multiphysics software. The investiga- tion reveals that the highest flow rate, and consequently the maximum surface charge density, is attained by a polycarbonate membrane with a pore size of 3 𝜇m, and is equal to 17.5 𝜇L/min experimentally. Furthermore, the research introduces two surface modifications applied to polycarbonate membranes. An atomic layer deposition of alumina results in a 10% reduction in pore size, remarkably increas- ing the electroosmotic flow rate by 30% and inducing a reversal in flow direction. Additionally, the deposition of gold on one side of a polycarbonate membrane leads to a substantial 1.85-fold increase in electroosmotic flow rate.