Recycled Polyethylene Terephthalate Fibers Aerogels Modified with Graphene Oxide for Adsorption of Methylene Blue and Coated with Polydimethylsiloxane Tetraethyl Orthosilicate for Oil Removal

Oil spills, industrial wastewater, and plastic waste have been widely considered major forces that cause severe impacts on the environment, threatening thousands of living creatures and humans. Hence, this study focused on a facile synthesis route of recycled polyethylene terephthalate aerogels modified with graphene oxide (GO-rPET-A) using poly(vinyl alcohol) as a binder, followed by a freeze-drying technique, to cope with pollutants leakage in wastewater. The prepared GO-rPET-A materials showed ultralow density (0.023–0.027 g/cm 3 ), high porosity (98–99%), and high content of mesoporous structure. The influence of graphene oxide (GO) concentrations on the methylene blue (MB) adsorption performance of GO-rPET-A was then investigated, reaching an adsorption rate of more than 99%. The flux rate of MB on GO-rPET-A was also affected after 10-cycle filtering, which occurred by hydrogen bonds and electrostatic interactions. Moreover, after being coated with polydimethylsiloxane-tetraethyl orthosilicate (PDMS-TEOS), the obtained hydrophobic PDMS-TEOS coated GO-rPET-A materials (H-GO-rPET-A) exhibited water resistant ability with a water contact angle of 146°, compressive stress up to 64 kPa, as well as performed high adsorption capacity (9.87 g/g) and selectivity of coconut oil in water. Finally, adsorption kinetics of GO-rPET-A with MB and H-GO-rPET-A with coconut oil was accessed via the pseudo-first-order and pseudo-second-order models. The innovative strategy of preparing hybrid aerogel from recycled polyethylene terephthalate fibers and GO expands applications in wastewater treatment by utilizing plastic waste.