Light-Mediated Polymerization Induced by Semiconducting Nanomaterials: State-of-the-Art and Future Perspectives

Abstract

Direct capture of solar energy for chemical transformation via photocatalysis proves to be a cost-effective and energy-saving approach to construct organic compounds. With the recent growth in photosynthesis, photopolymerization has been established as a robust strategy for the production of specialty polymers with complex structures, precise molecular weight, and narrow dispersity. A key challenge in photopolymerization is the scarcity of effective photomediators (photoinitiators, photocatalysts, etc.) that can provide polymerization with high yield and well-defined polymer products. Current efforts on developing photomediators have mainly focused on organic dyes and metal complexes. On the other hand, nanomaterials (NMs), particularly semiconducting nanomaterials (SNMs), are suitable candidates for photochemical reactions due to their unique optical and electrical properties, such as high absorption coefficients, large charge diffusion lengths, and broad absorption spectra. This review provides a comprehensive insight into SNMs’ photomediated polymerizations and highlights the roles SNMs play in photopolymerizations, types of polymerizations, applications in producing advanced materials, and the future directions.

Porphyrin-based donor–acceptor COFs as efficient and reusable photocatalysts for PET-RAFT polymerization under broad spectrum excitation

“… 23 The use of PCs for polymerizations offers access to well-defined polymeric materials with complex architectures under mild reaction conditions, 20 and heterogeneous PCs offer added advantages such as easy separation, recycling, and excellent purity of the final product free of catalysts contaminants. 24 Examples include small molecular PCs immobilized on heterogeneous supports, 25 as well as inorganic semiconductors such as perovskites, 26 CdSe quantum dots, 27,28 Bi 2 O 3 , 29 metal–organic frameworks (MOFs), 30–32 and plasmonic Ag 3 PO 4 . 33 Especially, MOFs and their nanosheets have been utilized in photoinduced 3D printing, exhibiting excellent oxygen tolerance and the ability to print complex objects.…”

In Situ Synthesis of Lead-Free Halide Perovskite–COF Nanocomposites as Photocatalysts for Photoinduced Polymerization in Both Organic and Aqueous Phases

“…Indeed, metal halide perovskites have been successfully employed in several photocatalytic reactions including hydrogen evolution, , CO 2 reduction, , small molecular transformation, − and radical polymerizations . In particular, photoinduced radical polymerizations have generated broad and significant interests as an efficient approach for the construction of macromolecules with complex architectures and precise chemical composition under mild reaction conditions. ,, Recent efforts in utilizing metal halide perovskite PCs for photopolymerization showcased similar or superior catalytic performances compared to the earlier developed metal complexes, − organic PCs, and inorganic semiconductors, , providing additional advantages, such as broad activation wavelength and cost-effective synthesis approach . However, a critical challenge for employing PNCs as PCs is their instability toward light irradiation and moisture .…”

“…1,14,15 Recent efforts in utilizing metal halide perovskite PCs for photopolymerization 13 showcased similar or superior catalytic performances compared to the earlier developed metal complexes, 16−18 organic PCs, 19 and inorganic semiconductors, 20,21 providing additional advantages, such as broad activation wavelength and cost-effective synthesis approach. 14 However, a critical challenge for employing PNCs as PCs is their instability toward light irradiation and moisture. 22 The poor photostability originates from the surface ligands desorption after long-time illumination, 22 which leads to the serious aggregation of NCs and thus reduces the surface catalytic sites.…”

Mathematical Description of the RAFT Copolymerization of Styrene and Glycidyl Methacrylate Using the Terminal Model

“…Unlike other modeling studies where neglection of the intermediate adduct results in qualitatively correct, but quantitatively inaccurate, predictions of the behavior of a RAFT polymerization system (Model 3 of [ 62 ]), the use of activation and transfer RAFT reactions resulted in our case in both qualitatively and quantitatively correct representations of the RAFT copolymerization of St and GMA. This model can be applied to other homo- and copolymerizations, and also extended to other systems, such as photo-RAFT polymerizations [ 15 , 70 , 71 , 72 ].…”