# Oxygen-Tolerant Inverse Microemulsion and Miniemulsion PhotoATRP

## TL;DR

This paper introduces a new method for making well-defined hydrophilic polymers using an efficient and oxygen-tolerant inverse emulsion process.

## Contribution

The first highly efficient and oxygen-tolerant inverse microemulsion and miniemulsion photoATRP using a dual catalytic system.

## Key findings

- The method allows precise synthesis of polymers with controlled molecular weight and low dispersity.
- The process is tolerant to oxygen and uses red light to excite methylene blue as a photocatalyst.
- The approach was extended to include other water-soluble photocatalysts and inverse miniemulsions.

## Abstract

Reversible deactivation radical polymerization (RDRP)
in an emulsion
is a practical and environmentally friendly route to well-defined
polymer synthesis. However, most emulsion RDRP has focused on conventional
oil-in-water systems, restricting accessible materials to hydrophobic
polymers. Here, we report the first example of a highly efficient
and oxygen-tolerant inverse microemulsion and miniemulsion photoinduced
ATRP (photoATRP) facilitated by a dual catalytic system. Irradiation
with red light efficiently excites the photocatalyst methylene blue
(MB+), facilitating the photoreduction of the deactivator
to initiate and mediate polymerization. This process enables the precise
synthesis of polymers with a controlled molecular weight, low dispersity
(Đ ≤ 1.20), excellent chain-end fidelity,
and temporal control. The versatility of this approach was further
demonstrated by expanding the photocatalyst scope beyond MB+ to include a library of other water-soluble PC. This method was
also successfully extended to the inverse miniemulsion. This work
establishes a practical inverse emulsion photoATRP for synthesizing
well-defined hydrophilic polymers.