Photoactive Surface-Grafted Polymer Brushes with Phthalocyanine Bridging Groups as an Advanced Architecture for Light-Harvesting

5 years ago

Photoactive Surface-Grafted Polymer Brushes with Phthalocyanine Bridging Groups as an Advanced Architecture for Light-Harvesting

Szczepan Zapotoczny, Łukasz Łapok, Karol Wolski, Agata Pomorska, Arkadiusz Gut, Tomasz Uchacz, Michał Szuwarzyński

Surface-grafted polymer brushes of novel ladder-like architecture were proposed for inducing ordering of chromophores embedded therein. The brushes with acetylene side groups were obtained by surface-initiated photoiniferter-mediated polymerization. The acetylene moieties reacted then through a “click” process with an axially azide-bifunctionalized silicon phthalocyanine bridging the neighboring chains that inherently adopt extended conformations in dense brushes. FTIR, quartz crystal microbalance, and atomic force microscopy were used to study formation and structure of the photoactive brushes varying in grafting densities. Importantly, photophysical properties of the chromophores were virtually unaffected upon embedding them into the brushes, as evidenced by UV/Vis absorption and emission spectroscopy. Owing to the unique ordering of the chromophores, the proposed method may open new opportunities for the fabrication of light-harvesting systems suitable for photovoltaic or sensing applications. A novel ladder-like architecture was proposed for surface-grafted photoactive brushes. Axially bifunctionalized phthalocyanines were used to bridge the chains adopting extended conformations in densely grafted brushes. Such an arrangement of chromophores makes the system promising for light-harvesting applications (see scheme).

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201702737