Scanning electron micrograph of macroporous pDCPD γFe₂O₃/Fe₃O₄ nanocomposite foam obtained via ring opening metathesis polymerisation (ROMP) of high internal phase emulsion. The FeO_x-NP composite ROMP foams are magnetic and can be attracted to a permanent magnet. Moreover, when subjected to an alternating magnetic field can be inductively heated. More details are presented by Sebastijan Kovačič et al, p 208.