02157nas a2200181   4500008004100000022001400041245015100055210006900206260000800275300001400283490000700297520144000304100002001744700002801764700002701792700002601819856013001845       2025                        eng d  a0024-929700aSquaraine dyes as efficient photoredox catalysts for PET-RAFT polymerization in batch and flow modes accelerated by suppression of dye aggregation0 aSquaraine dyes as efficient photoredox catalysts for PETRAFT pol  cMAR  a2850-28590 v583 a<p>
	Organic photoredox catalysts (PCs) based on squaraine dyes are investigated for photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization under visible-light (lambda max = 485 nm) irradiation in the presence of triethylamine that suppresses self-aggregation of dye and accelerates the polymerization. Several commonly used PCs are also screened, and self-aggregation is found to be reduced with triethylamine, thus providing a simple and effective approach to reduce aggregation of PCs. There is no induction period, and total polymerization time is shorter for squaraine dye PCs than for reported PCs under similar conditions. The photocatalyst system is amenable to polymerization by using different RAFT agents. Methyl methacrylate and a range of functional methacrylates are polymerized with good control over molecular weight and narrow dispersity in a first-order reaction with a random switch ``ON-OFF'' of the light source and even without an inert atmosphere. The mechanism of polymerization without and with requirement of triethylamine is elucidated using control experiments and found to be an oxidative and reductive electron transfer, respectively. A series of diblock and random copolymers of methyl methacrylate with methacrylate monomers are synthesized. Controlled polymerization is also demonstrated using a continuous-flow method and in an aqueous medium.</p>
1 aPatil, Anil, M.1 aNawghare, Indrajeet, S.1 aNithyanandhan, Jayaraj1 aAmbade, Ashootosh, V.  uhttps://library.ncl.res.in/content/squaraine-dyes-efficient-photoredox-catalysts-pet-raft-polymerization-batch-and-flow-modes