Reducing drag force on polyester fabric through superhydrophobic surface via nano-pretreatment and water repellent finishing

Abstract

Energy saving is a very important factor for athletics that works in high speed and award winning competition. Drag force is of prime importance for determining the speed of objects that moves in the fluid. Nanotechnology is of great potential among the methods for reducing drag force. Enhancing the fabric speed in the fluids could be achieved using superhydrophobic surfaces to reduce the drag force. A simple and versatile method was utilized for the fabrication of superhydrophobic surfaces via pad-dry-cure and in situ synthesis of ZnO nanoparticles as a pre-treatment. The treated samples were examined by SEM for assessing the structure and size of nanoparticles and mapping and EDX analysis was carried out for further characterization. A novel method was designed based on the tensile tester apparatus for studying the changes in drag force. The results indicated a reduction of 80% in drag force of the treated fabric in the optimum conditions of pre-treatment with 10% zinc nitrate (Zn(NO₃)₂) and 5% sodium hydroxide (NaOH) at 130 °C for 1 h.

Keywords:

• Drag force
• nanoparticles
• superhydrophobicity
• air permeability
• energy saving