Surfactant-free, spray-assisted water droplet templating for efficient fabrication of ultraviolet-curable polydimethylsiloxane sponge as a reusable oil cleanup sorbent

Abstract

The conventional fabrication methods for porous polymers involve high energy consumption and the use of chemicals and toxic additives, leading to environmental pollution. In the quest for energy-efficient and eco-friendly techniques, we developed a surfactant-free spray-assisted water droplet templating (SWDT) method for fabricating a polydimethylsiloxane (PDMS) sponge with efficient oil-absorbing properties. This method employs a spray atomizer to generate additive-free water droplets and ultraviolet curing to prepare a droplet-templated PDMS sponge, thereby being an environmentally friendly (no use of surfactant), easy (simple procedure and conventional equipment), and efficient (low time and energy consumption) way to fabricate porous structures. The resulting PDMS sponge exhibits high porosity (approximately 80.8 %), high oil absorption capacity (39.0 g/g), and excellent reusability without significant degradation of the structure and capacity. We expect that the SWDT method can contribute to the sustainable development of reusable porous polymer manufacturing because of its low environmental impact. This method holds promise for reusable polymer sorbent which can be utilized in oil spill accidents.