Beeswax-modified biopolymer aerogel: A sustainable approach to hydrophobic oil absorbing materials

Abstract

This study presents for the first time a sustainable approach to hydrophobic modification of nanocellulose/chitosan bioaerogels using beeswax emulsion. The incorporation of beeswax into the aerogel matrix resulted in increasing the density from 35.1 to 298 mg/cm3, while the porosity decreased from 96.4 to 62%. Fourier transform infrared spectroscopy (FT-IR) analysis confirmed the successful integration of beeswax into the nanocellulose/chitosan matrix, with distinct peaks corresponding to the characteristic functional groups of beeswax, such as C–H stretching vibrations, further validating the hydro - phobic modification. The mechanical properties showed increased hardness, from 0.24 to 0.95 N/mm2, indicating that higher beeswax content enhanced the rigidity of the aerogels. Contact angle measurements confirmed a dramatic improvement in hydrophobicity, with angles increasing from 47.68 to 134.40 and 128.11° for NC/CH 60-40-15. Water absorption capacity decreased from 17.5 g/g in the control sample to 8 g/g at the highest beeswax concentration, while oil absorption increased significantly, with fresh engine oil absorption rising from 3 to 45 g/g and used engine oil absorption from 2.5 to 40 g/g respectively. These results confirm the successful green modification of bioaerogels using beeswax, providing a sustainable and eco-friendly approach that enhances hydrophobicity, mechanical strength, and selective absorption properties.

Keywords

• biocomposite
• functional polymer
• biopolymer foams
• foam
• hydrophobicity