Sodium Dodecyl Sulfate-Reinforced ZIF-67-Based PDMS Hydrophobic Sponge for Efficient and Rapid Oil-Water Separation

To address the hydrophobicity and insufficient adsorption capacity for oily substances of polydimethylsiloxane (PDMS) sponges, this study designed and prepared an SDS-ZIF-67/PDMS composite sponge. First, ZIF-67 particles were incorporated into the PDMS matrix using a soft template method to construct a hydrophobic skeleton with a micro-nano rough structure. Subsequently, surface functionalization was performed using sodium dodecyl sulfate (SDS), and the grafted long carbon chains further significantly enhanced the material's lipophilicity. Finally, a high oil-absorption SDS-ZIF-67/PDMS composite sponge was successfully prepared. The results demonstrated that the composite sponge exhibited excellent adsorption capacity (12.42 g/g) for various oils and reached saturation in just 6 minutes. The sponge achieved a separation efficiency of up to 96% for various oil-water mixtures and demonstrated good cycling performance. These findings indicate that the SDS-ZIF-67/PDMS sponge has significant potential for application in oily wastewater treatment.