Synthesis, self-assembly and applications of functional polymers based on porphyrins

Porphyrins and their derivatives have attracted great attention due to their unique properties and diverse functionalities which contribute to their wide applications such as catalysis, solar cells, biomedicine and environmental science. It is interesting to note that porphyrin-containing polymers have recently aroused great interest due to the simultaneous presence of both porphyrinic and polymeric characteristics, especially for porphyrin-containing polymers linked by covalent bonds giving well-defined macromolecular architectures, unique self-assembly morphologies and promising applications. Herein, we summarize the different synthetic strategies and self-assembly protocols adopted in recent years to explore various applications of porphyrin-based functional polymers followed by a brief discussion on the challenges and outlooks for future research. With the discovery of advanced polymerization techniques such as living/controlled radical polymerization and click chemistry, the synthesis of porphyrin-containing functional polymers with well-defined architectures has been greatly developed. Porphyrin molecules tend to form the aggregates based on the self-assembly driving force of π-π stacking. Much attention has been paid to the self-assembly behavior of porphyrin-containing functional polymers, and various nanostructures have been constructed including nano-sized or micron-sized spheres, vesicles, belts, wires, rings, tubes, and rods. Porphyrin-containing functional polymers, with special photochemical and photophysical properties, present significant applications in photovoltaics, catalysis, biological and biomedicine fields. Particularly, the porphyrin-based photosensitizers for photodynamic therapy, porphyrin-conjugated polymers for solar cell devices, porphyrin-based polymeric nanocomposites in catalysis and chemical adsorption and separation have been widely studied. We hope this review on porphyrin-based functional polymers will be beneficial to researchers and newcomers in related fields.