Tuning surface wrinkles of Janus spheres in supercritical carbon dioxide

Abstract In this work we report a new way of producing wrinkled soft Janus spheres by using scCO 2 . The wrinkles appear in one of the half-hemispheres by the asymmetric UV irradiation of the particles followed by an anisotropic scCO 2 swelling. This treatment allows the fabrication of banded as well as sinusoidal packed wrinkles in the irradiated spheres surface. The particles were prepared from an elastomeric network consisting of two soft segments, polypropylene oxide and polybutadiene. The spheres to be treated by scCO 2 were selected taking into account the chemical composition as well as the elastic and wettability characteristics of the materials.