Sputter coating of styrofoam

Styrofoam is a trademarked brand of closed-cell extruded polystyrene foam (XPS), manufactured as insulation board used in walls, roofs, and foundations as thermal insulation and water barrier. SEM imaging is an ideal tool to check the size and homogeneity of the cells in a polymer foam structure, and if the material has a closed or open cell structure. Most polymer foams are good thermal and electrical insulators. This means that when they are scanned by the electron beam in a microscope, sample charging will often occur. Sputter coating is a perfect solution to avoid charging and degradation of the cell structure.

The name styrofoam is also used worldwide to refer to another material that is usually white in colour and made of expanded (not extruded) polystyrene foam (EPS). This material is often used in food containers, coffee cups, and as cushioning material in packaging. The trademarked term is used generically although it is a different material from the extruded polystyrene used for Styrofoam insulation.