Superhydrophobic microtextured polycarbonate surfaces

Abstract

A novel approach for fabrication of superhydrophobic polycarbonate (PC) surfaces has been developed based on purely physical process. Unlike the classical routes, which heavily rely on the surface chemical modification, the present route involves fabrication of microtextured Si master using high power pulsed laser and subsequent thermal replication of microtexture onto PC surface. The water droplet beads up on the microtextured PC in a Cassie–Baxter state exhibiting superhydrophobic nature of the surface. Average height of the micro-pillars formed on replicated PC surfaces played a crucial role in governing the superhydrophobic properties of the resulting microtextured surfaces. The water contact angle could be tailored over a wide range, from 82° for smooth PC surface to 155°, with an increase in average height of the micro-pillars from 1.34μm to 6.68μm. The infrared (IR) spectroscopy analysis revealed that the PC surface does not undergo any chemical change during thermal replication and further implied that the resulting superhydrophobic behavior was solely due to the physical modification of the surface. Moreover, the microtextured PC has been shown to be a perfect master for replication of microtexture onto other type of polymers such as polydimethylsiloxane (PDMS) in bulk and in thin film forms. Given the facile nature of the present technique and ease of fabrication, we believe that the present route is quite promising for large-scale production of PC based superhydrophobic surfaces. These surfaces find several potential applications such as anti-corrosive, anti-icing and self-cleaning surfaces, coatings inside of water pipes for frictionless flow and so on.