Development of hot embossing setup and fabrication of ordered nanostructures on large area of polymer surface for antibiofouling application

摘要

Nanostructured polymeric film has wide range of applications in different fields. However, the existing processes of fabrication of nanostructures on polymer surfaces are limited to very small area and throughput of the processes is very low. In order to solve this challenge, the indigenous hot embossing setup was developed which is capable of patterning micro-nano structures on large area. In this work, the steps for the development of hot embossing setup are discussed. The setup requires nanostructured mould, copper-chromium block, pencil heaters and temperature controlled system (thermostat and thermocouple). Two different types of nanostructures (groove and pillars) were successfully replicated on polystyrene film. The fabricated nanostructures were characterised using field emission scanning electron microscope and atomic force microscope. The dimensions of fabricated nanostructures are close to the mould dimensions with few defects (shrinkage defects). The wettability test was performed using goniometer on plain and structured polystyrene film to study the effect of structures on the wettability of the surface. It was observed that the hydrophilic (water droplet contact angle: 43 degrees) polystyrene film got converted into hydrophobic (water droplet contact angle: 102-112 degrees) nature. The fabricated structured surfaces have shown antibiofouling property which was confirmed through plate counting method.