Asymmetric Concave Polymer Nanostructures for MB, AF, and Cu²⁺ Ions Adsorption

Area of Science:

• Materials Science
• Environmental Chemistry
• Polymer Chemistry

Background:

• Methylene blue (MB), acid fuchsin (AF), and copper ions (Cu²⁺) are persistent and toxic aquatic pollutants.
• Efficient removal of these contaminants is vital for ecosystem and human health.
• Current adsorbent technologies require enhancement for complex pollutant mixtures.

Purpose of the Study:

• To synthesize and characterize an asymmetric concave polymer for pollutant removal.
• To evaluate the adsorbent's synchronous adsorption performance in binary pollutant systems.
• To elucidate the adsorption mechanisms and kinetics for MB, AF, and Cu²⁺.

Main Methods:

• One-step self-assembly synthesis of an asymmetric concave polymer using 3-aminophenol, formaldehyde, and ammonia.
• Acetone etching to refine the polymer's concave structure.
• Batch adsorption experiments to determine adsorption capacities and kinetics in binary systems (Cu²⁺/AF and AF/MB).

Main Results:

• The synthesized polymer exhibited high maximum adsorption capacities: 473.5 mg/g for MB, 1250.6 mg/g for AF, and 988.64 mg/g for Cu²⁺.
• Adsorption followed Langmuir (AF, Cu²⁺) and Freundlich (MB) models, indicating chemisorption.
• Pseudo-second-order kinetics suggested chemisorption as the rate-limiting step for all pollutants.

Conclusions:

• The asymmetric concave polymer demonstrates excellent synchronous adsorption capabilities for MB, AF, and Cu²⁺.
• Adsorption mechanisms involve electrostatic attraction, hydrogen bonding, and chemical complexation.
• The material shows significant potential for application in treating complex industrial wastewater.