Atom transfer radical polymerization initiated by activator generated by electron transfer in emulsion media: a review of recent advances and challenges from an engineering perspective

Atom transfer radical polymerization (ATRP) is a powerful initiation technique that has been used successfully to create a variety of advanced materials. ATRP induced by a benign reducing agent (AGET ATRP) is gaining popularity in emulsion media. The use of emulsion AGET ATRP in a two-step experimental procedure opens up new possibilities for developing environmentally friendly, low-cost, and less toxic catalytic systems. However, no study has specifically addressed the difficulties associated with ligand solubility, ligand-surfactant compatibility, and stirring speed when emulsion AGET ATRP is performed. Furthermore, only a few experimental studies have looked for scaling-up emulsion AGET ATRP, and no explicit mathematical model for this particular system has been reported so far. In this review paper, we discuss the experimental work done so far for the emulsion AGET ATRP. In addition, we show the modern technologies that have been used to address the drawbacks of emulsion AGET ATRP. This review paper also discusses the fundamentals and recent advances in empirical and statistical models developed to better understand the complex mechanism of emulsion AGET ATRP.