Ultrasound-Assisted RAFT Polymerization in a Continuous Flow Method

Democratization of Sono-RAFT: Reversible-Deactivation Radical Polymerization with Low-Frequency Ultrasound

“…Overall, we conducted sono-RAFT polymerizations at higher monomer concentrations than those for previously reported batch reactions and achieved molecular weights, distributions, and monomer conversions that match those achieved with high-frequency sono-RAFT in organic solvents. Sono-RAFT has already demonstrated promising results when coupled with continuous flow to polymerize at higher monomer concentrations, as well as forming higher-order morphologies with sono-RAFT-PISA. , This method serves to democratize sono-RAFT polymerization and enable more rapid advancements and discoveries in polymer chemistry.…”

“…However, until this report, sono-RAFT has been exclusively performed with high-frequency instruments that pose cost barriers for research endeavors. Existing sono-RAFT techniques necessitate specialized sonication horns or piezoelectric plates with high enough frequencies (∼400 kHz) to generate solvent-initiator radicals. − ,, Sono-RAFT shows promise as a tool to achieve higher-order polymer morphologies and has been adapted to work in conjunction with continuous flow to mitigate batch process challenges . Expanding the range of frequencies suitable for sono-RAFT to include low-frequency ultrasound devices, such as readily available ultrasonic jewelry cleaners, presents an economical alternative and paves the way for enhanced accessibility for controlled polymer synthesis.…”

In Situ Polymerization through Supramolecular Catalysis: A Convenient Approach to Cationic Polymer Synthesis with Real-Time Visualization

“…Cationic polymers, characterized by the presence of cations in either the main chain or side chain, have found a wide range of applications in diverse fields such as biomedicine, − gas sorption and separation, − wastewater treatment, , and heterogeneous catalysis. , To date, cationic polymers can be synthesized by a variety of methods such as atomic transfer radical polymerization, reversible addition–fragmentation chain transfer polymerization, and ring-opening metathesis polymerization, which primarily rely on metal catalysts, initiators, and chain transfer agents. − However, scientists are inclined to develop green polymerization strategies that can minimize the utilization of organic solvents, detrimental catalysts, and other additives in order to alleviate the environment burden. − For this reason, photopolymerization has been proposed as an ecofriendly method for the synthesis of cationic polymers, offering not only simplicity in operation and control but also rapid reaction rate, mild reaction condition, and narrow molecular weight distribution of the products . Unfortunately, the current photopolymerization systems still require the addition of initiators or photosensitizers for initiating the polymerization, while there remains a scarcity of examples in direct photoinitiation thus far .…”