The washing of filter cakes represents a central part of material treatment and purification in science, research, and industry. The displacement washing aims at removing residues or at recovering the target liquid. This study focuses on systems with two immiscible liquids, thus the washing liquid forms a phase boundary with the pore liquid. By coating a solid model system with silanes, different surface energies on the surfaces can be achieved while all other granulometric properties remain unchanged. In addition to experimental investigation of the filtration and washing characteristics, the measurement of the contact angles quantifies the wetting behavior between the solid and the liquid phase.