Aligned assembly of nano and microscale polystyrene tubes with controlled morphology

Polymer tubes with control on tube thickness and surface morphology are highly desirable for a wide range of applications in energy storage and transport as well as in tissue engineering and drug delivery. In this work, using the non-electrospinning Spinneret based Tunable Engineered Parameters (STEP) platform, we demonstrate fabrication of long (mm-cm) aligned polystyrene (PS) nano and microscale tubes in single and multiple layers. The tube outer diameters (0.3–3.6 μm), surface morphologies (pore size distribution: 20–200 nm) and tube wall thickness (50–500 nm) are controlled through tuning of the relative humidity, solvent type, and solution concentration (C/C*∼12). We experimentally show that incorporating MWCNTs into the tube structure significantly increases their ultimate strength and elongation. The tubes are also capable of sustaining high compressive radial pressures (0.2–0.6 MPa). When used as absorbents for oil cleaning, crisscross layers of porous PS tubes demonstrate higher absorption capacity compared with solid PS fibres (20–30% enhancement) and polypropylene (PP) fibres (90–110% enhancement).