Large Multipurpose Exceptionally Conductive Polymer Sponges Obtained by Efficient Wet-Chemical Metallization

Exceptionally conductive (250 S cm−1), very fast electrically heatable, thermally insulating, antimicrobial 3D polymeric sponges with very low density (≈30 mg cm−3), superhydrophobicity, and high porosity, their method of preparation, and manifold examples for applications are presented here. The electrical heatability is reversible, reaching 90 °C with 4.4 W in about 19–20 s and cooling immediately on switching off the voltage. The sponges show high contact angles >150° against water on the sponge surface as well as inside the sponge. Water droplets injected into the sponges are ejected. A facile wet‐chemical method established for macroscopic melamine–formaldehyde sponges is the key for the thorough in‐depth surface metallization of the sponges. The coating thickness and uniformity depend on the metallization formulation, conditions of metallization, and the type of metal used. A scanning electron microscope is used for morphology characterization. A reduced metallization rate in air is highly critical for the in‐depth uniform coating of metals. The resulting metallized sponges could be highly interesting for heating as well as insulation devices in addition to oil/water separation membranes. Electrically heatable metallized 3D polymer sponges of macroscopic dimensions with exceptional conductivity (240 S cm−1), thermally insulating, and superhydrophobic properties are shown. The multipurpose sponges are prepared by in‐depth homogeneous wet metallization of melamine‐formaldehyde sponges.