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This article describes the synthesis and characterization of a UV-crosslinked Eosin Y-photocatalytic gel and studies its performance in the oxidation of thioanisole in batch and flow reactors. 

We screen various acid catalysts (mineral, carboxylic, carbonic acids, zeolites, ionic liquids, and metal salts) for PET hydrolysis. 

PET non-catalyzed, non-isothermal hydrolysis can produce 94% terephthalic acid (TPA) yield in 75 seconds. 

Abstract Heterogeneous photocatalysis combines the benefits of light‐mediated chemistry with that of a catalytic platform that facilitates re‐use of (often expensive) photocatalysts. This provides significant opportunities towards more economical, sustainable, safe, and user‐friendly chemical syntheses of both small and macromolecular compounds. This contribution outlines recent developments in the design of heterogenous photocatalysts and their use to mediate polymerizations. We outline four classes of heterogeneous photocatalysts in detail: Nanoparticles, conjugated and non‐conjugated polymer networks, metal‐organic frameworks (MOFs), and functionalized solid supports. 

Post-consumer polyethylene terephthalate (PET) was hydrolyzed in pure water over a wide range of temperatures (190−400 °C) and pressures (1−35 MPa) to produce terephthalic acid (TPA). Solid or molten PET was subjected to water as a saturated vapor, superheated vapor, saturated liquid, compressed liquid, and supercritical fluid. The highest TPA yields were observed for the hydrolysis of molten PET in saturated liquid water. Isothermal and non-isothermal hydrolysis of PET was also explored. Rapidly heating the reactor contents at about 5−10 °C/s (“fast” hydrolysis) led to high TPA yields, as did isothermal PET hydrolysis, but within 1 min instead of 30 min. Notably, these conditions resulted in the lowest environmental energy impact metric observed to date for uncatalyzed hydrolysis. 

Polymer nanoparticles are an emerging class of materials with potential impact in sensing, catalysis, imaging, cosmetics, and therapeutics. Here, a collection of graft polymers with conjugated polythiophene backbones were synthesized via a grafting-to approach. We functionalized polythiophene backbones with side chains of either poly(3-hexylthiophene) (P3HT), poly(ethylene oxide), or poly(methyl methacrylate) (PMMA) via copper-catalyzed azide–alkyne click chemistry. The backbones, graft polymers and a linear poly(3-hexylthiophene) were fabricated into nanoparticles through precipitation in aqueous media. We measured the absorption and emission spectra of the polymers dissolved in chloroform and as nanoparticles suspended in water. Compared to linear P3HT, all graft polymer nanoparticles exhibit higher quantum yields. Moreover, the addition of PMMA side chains increased the quantum yield by more than two orders of magnitude. This versatile approach to conjugated graft copolymer synthesis demonstrates a route for enhancing photoluminescence of conjugated polymer nanoparticles that could be beneficial for a variety of applications, such as biosensing and bioimaging. 

NIPAAm and fluoresceino-acrylate are copolymerized on glass beads to develop multiresponsive heterogeneous photocatalysts that exhibit structural changes at elevated temperatures and alter their photocatalytic performance in wastewater remediation. 

This article describes the development of polymer brush-based heterogeneous photocatalysts for PET-RAFT polymerization in aqueous environments. 

This contribution discusses the control over polymerizations using a heterogeneous photocatalyst based on fluorescein polymer brushes tethered to micron-scale glass supports (FPB@SiO 2 ). FPB@SiO 2 -catalyzed photoinduced electron/energy transfer-reversible addition–fragmentation chain transfer (PET-RAFT) polymerization is shown to provide high conversions, controlled molecular weights and narrow molecular weight distributions for a variety of monomers. Moreover, the beads can catalyze PET-RAFT on gram scales, in the presence of oxygen, while allowing full catalyst recovery through simple filtration. Finally, their high shelf-life allows for multiple polymerizations and user-friendly access to precision macromolecules under mild reaction conditions even after prolonged (months) storage time.