Sulfur-Dot-Mediated Synthesis of Smart Polymers for Heavy Metal Removal
Subrata Dolui, Bhanendra Sahu, Srayee Mandal, Santanu Bhattacharyya, Sanjib Banerjee
Abstract
An excellent level of control for the ambient temperature radical polymerization of 2-hydroxyethyl methacrylate (HEMA), yielding well-defined poly(2-hydroxyethyl)methacrylate (PHEMA) (at least up to 18900 g mol –1 ) with low dispersity (≤1.24), was achieved via ultrasmall S-dots-mediated reversible deactivation radical polymerization. The high chain-end functionality of synthesized PHEMA-Br was demonstrated by the synthesis of PHEMA and poly(2-hydroxyethyl methacrylate)- block -poly( tert -butyl methacrylate) (PHEMA- b -PtBMA) diblock copolymers. Hydrolysis of the tert -butyl ester groups of the PtBMA segment led to the synthesis of dual thermo/pH-responsive poly(2-hydroxyethyl methacrylate)- block -poly(methacrylic acid) (PHEMA- b -PMAA) diblock copolymer, bearing thermoresponsive PHEMA and pH-responsive PMAA segments. This polymer is responsible for lead (Pb) removal from wastewater.