High internal phase emulsion templated scaffold of crosslinked polyetherimide for high temperature oil sorption

Abstract

The growing risk of oil spills from industrial operations has created an urgent requirement for efficient contamination remediation solutions. Conventional methods are often labor-intensive, resource-demanding, and environmentally harmful. Three-dimensional (3D) scaffolds, akin to lattice girders in building construction, offer structural durability and can serve as highly efficient oil sorbent. The fabrication of 3D scaffolds is a preferred method for removing contaminants, particularly oil from oily wastewater, owing to their exceptional oil sorption capacity. Present research examined the development of a new, high-temperature-stable adsorbent material for oil spill remediation. Polyetherimide (PEI) based macroporous scaffolds were fabricated via high internal phase emulsion (HIPE) templating and freeze-drying to exploit their high oil sorption capacity and high temperature stability. The scaffolds were crosslinked with ethylenediamine (EDA) to increase their mechanical resiliency and utility for multiple use cycles. Characterization techniques such as optical microscopy, SEM, FTIR and gravimetric tests were carried out to evaluate the structure and efficacy of the scaffolds. Oil sorption capacity of scaffolds was assessed at room temperature and at 150°C, and a significant increase in sorption capacity was found at high temperature. Kinetic modeling using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models revealed that physisorption is the dominant mechanism. Wettability of the scaffolds was investigated using capillary pressure measurements which demonstrated an easy oil adsorption into the porous framework. To complement the detailed performance metrics provided, this study also presents an in-depth discussion of the underlying mechanisms, emphasizing multi-stage oil adsorption involving bulk diffusion, film diffusion, and intraparticle transport. Capillary-driven wicking and the scaffold’s open-cell architecture facilitate rapid oil uptake. Current study has demonstrated the application of PEI-based HIPE scaffolds as a very efficient, low-cost, and eco-friendly approach for high-temperature oil spill remediation, which may further be used to several untapped applications.