Fish Gill-Inspired Bidirectional Porous Polysaccharide Aerogels for Micro/Nanoplastics Removal

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Micro/nanoplastics (MNPs) contaminate freshwater ecosystems and pose risks to human health.
• Conventional MNP removal methods are often inefficient.
• There is a critical need for advanced MNP remediation technologies.

Purpose of the Study:

• To develop a sustainable and efficient material for micro/nanoplastic removal from water.
• To investigate the adsorption mechanisms and performance of a novel aerogel.
• To assess the antibacterial properties of the developed material.

Main Methods:

• Fabrication of a chitosan, cellulose nanofibers, and polydopamine-based aerogel with bidirectional porosity.
• Characterization of aerogel adsorption capacities for various MNP types.
• Utilizing molecular dynamics (MD) simulations to understand adsorption interactions.
• Testing a continuous-flow adsorption column for MNP removal efficiency.
• Evaluating antibacterial activity against E. coli.

Main Results:

• The bidirectionally porous aerogel exhibited outstanding adsorption capacities exceeding 300 mg/g for diverse MNPs.
• Directional pore alignment significantly enhanced adsorption capacity (over 9x) compared to random structures.
• MD simulations identified strong multimodal interactions (electrostatic, vdW, H-bonding, π-π) driving MNP adsorption.
• A continuous-flow system achieved over 96% MNP removal from 1 L of contaminated water in 20 minutes.
• The aerogels demonstrated excellent antibacterial activity in acidic conditions.

Conclusions:

• Bioinspired, bidirectionally porous aerogels offer a highly effective and sustainable solution for MNP remediation.
• Tailored surface chemistry, directional pore alignment, and multimodal interactions are key to enhanced MNP adsorption.
• The developed aerogels present a scalable technology for wastewater treatment with added antibacterial benefits.