Size effect of semiconductor quantum dots as photocatalysts for PET-RAFT polymerization

Abstract

Larger QDs result in a higher polymerization rate and a better fit of Mn,GPC with Mn,theoretical for PET-RAFT polymerization using CdSe QDs photocatalysts.

Visible Light‐Regulated Heterogeneous Catalytic PET‐RAFT by High Crystallinity Covalent Organic Framework

“…To recover and reuse the catalysts from polymerization system, extensive efforts have been developed to exploit heterogeneous catalysts for triggering RDRP. [ 40–43 ] For example, metal‐organic frameworks (MOFs) based porous materials were served as photocatalysts for synthesizing functional polymers in ATRP, [ 44,45 ] revealing efficient monomer conversion and recycling performance. Furthermore, post‐modification strategy provides a promising method for preparing heterogeneous photocatalysts with good catalytic and recyclable performance in photo‐electron transfer (PET)‐RAFT polymerization.…”

New Light in Polymer Science: Photoinduced Reversible Addition-Fragmentation Chain Transfer Polymerization (PET-RAFT) as Innovative Strategy for the Synthesis of Advanced Materials

“…The photoredox catalysts herein described are just a part of the wide classes of PCs suitable for PET-RAFT polymerization. Less common photocatalysts that have been used for PET-RAFT purposes are Perovskite nanocrystals (CsPbBr 3 ) [ 40 ], CdSe quantum dots (QDs) [ 41 , 42 ], tertiary amines (tris(2-(dimethylamino) ethyl)amine, N , N , N ′, N ′′, N ′′-pentamethyldiethylenetriamine, and triethylamine) [ 43 ], and graphitic carbon nitride [ 44 ]. In Table 1 the main advantages and disadvantages of the most used catalysts are reported.…”

Heterogeneous photocatalytic reversible deactivation radical polymerization

“…Free-radical polymerization catalyzed by QDs under a one-or two-photon process has been conducted by various research groups. 49,50,75,[81][82][83][84][85] Moving on from these works, Egap, 33,61,86 Pang 87,88 and Weiss 57 pioneered the use of CdSe QDs as photocatalysts for RDRP.…”

“…To explore the QD size effect in HP-RDRP, Pang and coworkers investigated PET-RAFT polymerization of MMA using CdSe QDs of different diameters, 3.8 nm (G), 5.1 nm (Y) and 6.8 nm (R) (the abbreviations represent the fluorescence colour of QDs under 365 nm UV light excitation). 88 The polymerization was conducted in DMF under blue (465 nm), green (532 nm) and white light, and sunlight with CPADB serving as the CTA. Under blue light irradiation, the polymerization catalyzed by R showed the highest monomer conversion (72%), highest molecular weight (M n = 14.6 kg mol −1 ) and lowest dispersity (Đ = 1.17) in 28 h.…”