Bentonite-PDMS composite foams for oil spill recovery: Sorption performance and kinetics

摘要

The aim of this article is the synthesis and characterization of bentonite-filled siloxane foams for oil spills recovery. Composite foams at varying filler content in the range 35-45 wt were investigated. The sorption kinetics and capacity of composite foams in different oils (e.g., kerosene, virgin naphtha, pump oil) were assessed. As a reference, water absorption capacity was also evaluated. Among all, the composite foam filled with 40 wt bentonite (B-40 batch) shows the lowest affinity with water and good absorption capacity with oils (mainly light oils) reaching an absorption capacity at saturation equal to 10.3 and 518.2 wt in water and virgin naphtha, respectively. Furthermore, isothermal absorption curves were analyzed using three kinetic models: pseudo-first order, pseudo-second order, and Elovich models. The equilibrium isotherm fitting results were optimal using the pseudo-second order model, indicating that chemisorption phenomena play a key role in the speed of the absorption phase for these PDMS-based composite foams. Finally, a correlation was addressed between morphology, foam microstructure, absorption capacity, and kinetics.