# Rapid microwave assisted RAFT synthesis of amphiphilic HEMA-co-AMPS copolymers for high performance Cu2+ and Cr6+ removal from water

## TL;DR

A new fast method creates a polymer that efficiently removes harmful copper and chromium ions from water.

## Contribution

A rapid microwave-assisted RAFT synthesis method for creating amphiphilic HEMA-co-AMPS copolymers with high metal ion adsorption performance.

## Key findings

- The copolymer achieved maximum Cu2+ and Cr6+ adsorption capacities of 165 mg g⁻¹ and 115 mg g⁻¹ within 3 hours.
- Adsorption followed pseudo-second-order kinetics and was best modeled by Langmuir for Cu2+ and Freundlich for Cr6+.
- The copolymer retained over 87% of its adsorption capacity after multiple cycles, showing strong reusability.

## Abstract

An amphiphilic HEMA-co-AMPS copolymer was synthesized through microwave-assisted RAFT polymerization using a rapid and energy-efficient approach. Comprehensive characterization confirmed successful copolymer formation, high structural stability, and the presence of abundant negatively charged sulfonate groups. The copolymer exhibited excellent adsorption performance toward Cu2+ and Cr6+ ions, achieving maximum capacities of 165 mg g⁻¹ and 115 mg g⁻¹, respectively, within ≤ 3 h. Adsorption followed a pseudo-second-order kinetic model, while equilibrium data were best described by the Langmuir model for Cu2+ and the Freundlich model for Cr6+. Thermodynamic analysis indicated spontaneous adsorption, with Cu2+ uptake occurring through an endothermic process and Cr6+ uptake proceeding exothermically. The copolymer retained more than 87% of its initial adsorption capacity after multiple cycles, demonstrating strong reusability. Overall, these findings highlight microwave-assisted RAFT polymerization as an efficient and sustainable strategy for producing high-performance polymeric adsorbents for water treatment applications.