Fluid imbibition into PMETAC functionalized mesoporous films

Fluid imbibition into nanoporous films is of relevance in water harvesting, separation, or sensing. Furthermore, grafting polymers from the mesopore walls affects the wettability and ionic accessibility of mesoporous films. Using poly[2-(methacryloyloxy)ethyltrimethylammonium chloride] (PMETAC) functionalized mesoporous films we observe that the imbibition of aqueous salt solutions depends on many parameters such as the fluid, the mesopore structure, polymer ion interaction and osmotic effects. Specifically, we observe that the imbibition length depends on the salt concentration and the type of salt as well as on the presence of PMETAC. We identified the PMETAC influence on an osmotically driven, self-amplified fluid pumping mechanism using PMETAC functionalized mesoporous silica films. The presence of the polyelectrolyte PMETAC offers a further parameter to tune fluid imbibition into mesoporous films, especially in the presence of interacting ions. The results give insights on how to design porous materials with applications in sensor or separation technology or in material system design e.g. looking at material exchange between drop compartments.