A novel tertiary amine catalyst (TAC) and trithiocarbonate (TTC) synergistic photo-induced controlled radical polymerization of methacrylates in the absence of conventional photoinitiators, metal-catalysts, or dye sensitizers, has been realized under mild UV irradiation (λ max ≈ 365 nm), yielding polymethacrylates with low molecular weight distributions and excellent end-group fidelity (> 95%).

Novel polymer grafted metal-organic framework (MOF) nanoparticles were synthesized. The formed core/shell nanoparticles exhibit outstanding water dispersity and pH sensitivity, and show their catalytic effect for the reduction reaction of 4-nitrophenol (NP) to 4-aminophenol (AP) when loaded with Pd(0) catalyst.

This study presents a novel approach to synthesize biocompatible single-chain polymeric nanoparticles (SCPN) under mild reaction conditions via organo-catalyzed ring-opening polymerization (ROP). Linear polymeric precursors containing pendent polymerizable caprolactone groups, made by reversible addition−fragmentation chain transfer (RAFT) polymerization, were intramolecularly crosslinked via ROP in the presence of benzyl alcohol (nucleophilic initiator) and methanesulfonic acid (organo catalyst) to form discrete, well-defined SCPN, as confirmed by GPC, DLS, 1 H NMR, and AFM analysis. The formed SCPN are tunable in size (2−5 nm), depending on the molecular weight of the parent linear macromolecule. Furthermore, cytotoxicity studies revealed that the SCPN, which were covalently cross-linked by biodegradable polyester linkages, were nontoxic toward human embryonic kidney (HEK293T) cells. This study demonstrates the efficiency and versatility of this approach to generate uniformly sized soft nanoparticles with tunable dimensions that are potentially useful for a range of targeted applications, including drug delivery systems and membranes for gas separation technologies.

The generation of nanoscale polymer films using complex, hierarchically structured (bio)macromolecular architectures has important implications in the field of materials science. This study details the surface-confined covalent cross-linking of micellar macrocross-linkers derived from the amphiphilic diblock copolymer, polystyrene-b-poly(N-(2hydroxypropyl)methacrylamide), via atom transfer radical polymerization (ATRP)-mediated continuous assembly of polymers (CAPATRP), to generate compartmentalized thin films with unique surface morphologies. Using initiator-functionalized silicon wafers, the micellar films were found to be thicker in comparison to thin films prepared from linear macrocrosslinkers derived from poly(N-(2-hydroxypropyl)methacrylamide) (15.2 vs 10.2 nm). Unlike the smooth and flat surface morphologies observed for films prepared from the linear macrocross-linker, the micellar films possessed distinctive pitted morphologies that became more pronounced after annealing. Furthermore, the hydrophobic polystyrene cores of the micelles enabled the encapsulation of hydrophobic molecules that subsequently remain compartmentalized during the CAP process, as demonstrated with the encapsulation of the dye, Nile Red. The assembly of Nile Red loaded micelles onto initiator-functionalized silica particles was confirmed via fluorescence microscopy. This study demonstrates the efficiency and versatility of the CAP approach to generate nanostructured thin films with controllable morphology, surface roughness, thickness and composition, simply by varying the macromolecular architecture.

This study presents the development of a novel solid state photocatalyst for the photoinduced controlled radical polymerization of methacrylates under mild UV irradiation (λmax ≈ 365 nm) in the absence of conventional photoinitiators, metal-catalysts or dye sensitizers. The photocatalyst design was based on our previous finding that organic amines can act in a synergistic photochemical reaction with thiocarbonylthio compounds to afford well controlled polymethacrylates under UV irradiation. Therefore, in the current contribution an amine-rich polymer was covalently grafted onto a solid substrate, thus creating a heterogeneous catalyst that would allow for facile removal, recovery and recyclability when employed for such photopolymerization reactions. Importantly, the polymethacrylates synthesized using the solid state photocatalyst (ssPC) show similarly excellent chemical and structural integrity as those catalysed by free amines. Moreover, the ssPC could be readily recovered and re-used, with multiple cycles of polymerization showing minimal effect on the integrity of the catalyst. Finally, the ssPC was employed in various photo-“click” reactions, permitting high yielding conjugations under photochemical control.