A layer-by-layer assembled superhydrophobic composite aerogel for rapid and high-capacity removal of microplastics from beverages

Abstract

The hierarchical integration of porous materials with rigid frameworks and biopolymer components enhances their adsorption performance. While combining porous substances with cellulose nanofibers (CNFs) to create high-performance hybrid aerogels holds significant potential, achieving this remains challenging due to suboptimal interfacial bonding and insufficient structural reinforcement from CNFs. In this study, a superhydrophobic composite aerogel (AG^U6-(OH)₂@PMSQ) was synthesized using a sequential bottom-up and layer-by-layer in situ growth strategy based on a robust dual-network structure formed by the “egg-box structure” and CNFs. The hierarchical porosity and superhydrophobicity of AG^U6-(OH)₂@PMSQ provided excellent adsorption capacity and sensitivity for polystyrene microplastics (PSM). The adsorption kinetics revealed that the adsorption capacity for PSM reached an impressive 555.556 mg g⁻¹ within a short timeframe of 100 min. D–R model analysis indicated that hydrophobic interactions were the primary driving force behind the adsorption of PSM by AG^U6-(OH)₂@PMSQ. Meanwhile, simulation calculations confirmed that hydrogen bonding and C–H⋯π interactions also contribute to the adsorption process. Furthermore, AG^U6-(OH)₂@PMSQ demonstrated exceptional adsorption stability, reproducibility, and a high PSM removal rate in aqueous matrices. This innovative research offers a new insight for contaminant control in complex matrix environments.