Methyltrimethoxysilane-coated recycled polyethylene terephthalate aerogels for oil spill cleaning applications

Recycled polyethylene terephthalate (rPET) aerogels are successfully developed using rPET fibers from plastic bottle wastes for oil spill cleaning applications. The rPET aerogels are formed via a freeze-drying process with polyvinyl alcohol (PVA) and glutaraldehyde (GA) crosslinking agents. After coating with methyltrimethoxysilane (MTMS), the MTMS-coated rPET aerogels exhibit hydrophobicity with a water contact angle of 133 degrees-141 degrees for oil absorption applications. The effects of the rPET fiber concentrations, fiber deniers and cross-linker contents on the oil absorption performance of the rPET aerogels are comprehensively quantified. The 0.5 wt% rPET aerogels show the largest oil absorption capacity of 79.4 g/g, approximately 7.0 and 3.2 dines better than commercial sorbents, polypropylene pads and polypyrrole sponges, respectively and slightly larger than 0.5 wt% cellulose-based aerogels from paper waste. From the oil absorption kinetics of the rPET aerogels quantified by the pseudo-first and pseudo-second order models, the 0.5 wt% rPET aerogels can absorb oil up to 3.0 times faster than cellulose-based aerogels. In addition, rPET aerogels are also demonstrated to have a good absorption capacity for different organic solvents. These establish the novelty of the contribution and demonstrate that rPET aerogels can be promising materials for absorption applications due to their high absorption capacities, environmental-friendly and cost-effective fabrication method.