Fabrication of hierarchical feather-mimetic polymer nanofibres

Highlights: • Hierarchically feather-mimetic structures formed of PMIA nanofibres were fabricated by electrospinning and subsequent hydrothermal reaction. • Crystallised PMIA nanoflakes formed during hydrothermal reaction, constructed a nanosized fine texture on top of the coarser-textured membrane. • After fluorination, the membrane exhibited superamphiphobic property. In this study, hierarchically feather-mimetic structures formed of poly(m-phenylene isophthalamide) (PMIA) nanofibres were prepared by electrospinning and subsequent crystallisation for superwettability applications. X-ray diffraction measurementsand scanning electron microscopy show that a feather-mimetic structure of crystallised nanoflakes was formed following a hydrothermal treatment process. The nanoflakes formed a nanosized fine texture on top of a coarser-textured membrane, which greatly improved the membrane roughness and yielded a hierarchical topography. After fluorination, the membrane exhibited superamphiphobicity, with surface contact angles of 151° and 136° for water and hexadecane, respectively. The method provides new insight for the design and development of functional bionic membranes based on PMIA.