Novel pressurised gyration device for making core-sheath polymer fibres

Highlights: • Core-sheath polymer fibres are formed in a novel way. • A new twin-reservoir device has been designed and constructed to enable this. • The device was subjected to pressurised gyration. • Microstructural characterisation confirms core-sheath fibre formation. • Nanoparticles have been successfully incorporated in the product. -- Abstract: Core-sheath fibres of two polymers were generated using a novel set-up where rotating speed and pressure can be varied at ambient temperature. The specially designed spinneret consists of inner and outer chambers which can accommodate two polymers and other additives. The new methodology was demonstrated using poly(ethylene oxide) and poly(methylmethacrylate) (PMMA). Dyes were used as colouring agents for the polymers to verify core-sheath formation, and optical, scanning and fluorescent microscopy of the formed fibres confirmed the presence of a core-sheath combination. The core diameter obtained was in the range 5–10 μm and the sheath fibre diameter was 20–30 μm. The core/sheath diameter can be pre-set by selecting the forming conditions. To show the flexibility of the new method, nanoparticle containing PMMA fibres were also produced using the new device and incorporation of the nanoparticles in the sheath and core of the fibres was verified by electron microscopy and energy-dispersive X-ray spectroscopy analysis. A high yield of fibre was obtained and with more severe forming conditions the size of core-sheath fibres generated can be reduced to the nanoscale. Thus, the new process has a real capability of manufacturing a wide variety of novel functional materials and structures in a single scalable set-up.