Study on Oil–Water Separation Performance of PDA/ODA Composite–Modified Sponge

ABSTRACT The study involved the modification of a melamine sponge (SP) through the introduction of polydopamine (PDA) and octadecylamine (ODA), resulting in the creation of three distinct sponge types: PDA/ODA@SP, PDA@SP and ODA@SP. The successful modification of PDA and ODA onto the surface of the sponge was confirmed through the utilisation of scanning electron microscopy and x‐ray photoelectron spectroscopy. Consequently, the resulting sponges exhibited a unique micro–nano composite structure. Wettability testing was conducted to assess the properties of the sponges, revealing that the PDA/ODA@SP sponge demonstrated hydrophobic superlipophilic characteristics. Moreover, a series of 10 repeated oil–water separation experiments indicated that the PDA/ODA@SP sponge achieved an impressive separation efficiency of up to 97%, demonstrating its exceptional oil–water separation capabilities and reusability. Additionally, investigations utilising soybean oil and engine oil demonstrated the composite sponge's superior absorption capabilities for fatty acids and hydrocarbons.