Large-area customizable honeycomb patterned polycarbonate derived from roofing sheet waste for a slippery liquid-infused porous surface

Polycarbonate (PC) is widely recognized for its exceptional ductility, high heat resistance, and impressive transparency, making it a material of great importance and extensive use. However, the increasing accumulation of PC-based solid waste, particularly discarded roofing sheets, has raised significant environmental concerns worldwide. The incineration or incomplete decomposition of polycarbonate waste in landfills generates hazardous by-products such as microplastics and Bisphenol-A (BPA). In this study, we propose an innovative recycling approach that converts low-grade roofing sheets waste into large-area customizable honeycomb-patterned PC, offering great potential for the development of slippery liquid-infused porous surfaces (SLIPs). The achievement of a highly ordered honeycomb pattern array is facilitated through the implementation of an improved phase separation (IPS) method, employing methanol as a pore inducer and template droplet stabilizer, thereby eliminating the necessity for surfactants or specially engineered polymers. This approach enables the formation of a monolayered pattern array with uniform closed dead-end pores shaped like round flowerpots, holding immense promise for creating SLIPs with self-cleaning, anti-fouling and electrification properties due to the reduction in surface-contaminant adhesion and friction, rendering them suitable for various applications, including smart coatings for rain corrosion protection and falling raindrop energy harvesting.