Advanced fabrication and application of pineapple aerogels from agricultural waste

ABSTRACT

Over twenty million tons of pineapples have been produced annually worldwide, but their waste is mostly discarded or burnt after harvesting. In this work, the high-value added aerogels from the pineapple leaf waste are developed for the first time by using polyvinyl alcohol (PVA) cross-linkers and a cost-effective freeze drying process. The pineapple fibre (PF) aerogels have highly porous structures with the porosities of 96.98–98.85%, ultra-low densities of 0.013–0.033 g/cm³, and hydrophobicity with water contact angles of approximately 140°, after a surface modification with methyltrimethoxysilane (MTMS). The effects of PF concentrations (0.5–2.0 wt.%) on oil and organic solvent adsorption are investigated comprehensively. Experimental results indicate that the hydrophobic PF aerogels can adsorb motor oil up to 37.9 g/g, approximately two times greater than commercial polypropylene and polyurethane sorbents. The pseudo-second order model can provide a good fit for the oild adsorption kinetics of the developed aerogels.

KEYWORDS:

• Pineapple fibre
• agricultural waste
• aerogel
• oil adsorption
• morphology

Highlights

• Cost-effective pineapple fibre (PF) aerogel was developed successfully for the first time

• MTMS-coated PF aerogels have hydrophobicity with water contact angles of over 140°

• Oil and organic solvent adsorption of the PF aerogels are larger higher than commercial sorbents

• Pseudo-second order model is the best oil adsorption kinetics of the PF aerogels

Acknowledgments

The authors deeply acknowledge the lab staffs in Division of Materials Science, Department of Mechanical Engineering, NUS for their significant help on characterizations.

Disclosure statement

No potential conflict of interest was reported by the authors.