Hierarchically Porous Bio-Based Sustainable Conjugate Sponge for Highly Selective Oil/Organic Solvent Absorption

This paper describes a novel conjugate biodegradable sponge based on the tree gum kondagogu with excellent selective oil/organic solvent absorption ability. The conjugate sponge is made hydrophobic (water contact angle 133°) by post-process vapor phase silylation, has porosity of ≈94% with very low density (18.4 mg cm⁻³). The sponge can absorb selectively up to 19–43 times its weight of oils and organic solvents. Meanwhile, good reusability is also observed in up to at least 10 cycles. The biodegradation behavior is studied from BOD (biological oxygen demand) analysis, where the non-silylated and silylated sponges degraded over 28 days by 92% and 76%, respectively, in waste-water sludge. The novel conjugate bio-based and biodegradable sponge used in this study is a promising sustainable material for clearing oil spills and for water treatment.