Self-aggregation behavior of well-defined PEO-based amphiphilic tri-block copolymers and their application as metal detectors

PMMA-b-PEO-b-PMMA tri-block copolymers were synthesized by anionic polymerization technique usingtelechelic1,1-diphenylethylene-terminated poly (ethylene oxide)as macroinitiators and Sec-BuLi four tri-block copolymers of PMMA-b-PEO-b-PMMA with different number average molecular weight (M<overline>n) were synthesized, and the structure of the macroinitiators and polymers was confirmed by FTIR. and1H NMR spectroscopic methods. Through the solvent-induced association, the aqueous solutions of PMMA-b-PEO-b-PMMA were formed. After that, hydrodynamic diameter, DLS and TEM were used to study the morphology of the resulting aqueous solutions. The polymer's self-assembled nanostructures of core-shell flower-like spherical micelles structures were observed. Also, the PMMA hydrophobic content of the tri-block increases steadily and the core size of the micelles decreases significantly, due to reverse micelle formation in which the core is hydrophobic PMMA blocks and the corona is PEO block. This micelle is an excellent detector for metal ions and acts as a reducing agent for them to convert into pure nontoxic nanoparticles.