投2025-0029

発表論文	Developing marine biodegradable polymers with biodegradabilities controlled using metal-free photocatalysts due to their antibacterial properties under sunlight
発表者名	○増井 昭彦、豊島 有瑞子、井川 聡、他
掲載誌/掲載箇所	Polymer Degradation and Stability Volume 241, 111526
発表日	2025/7/31

概要

The ability to control how a functional biodegradable polymer biodegrades is critical. Herein, the potential of the metal-free graphitic carbon nitride (gC3N4) photocatalyst, which is mildly photocatalytic compared to strong photocatalysts such as TiO2, is evaluated for its ability to control biodegradable-plastic biodegradation in the marine environment. gC3N4 is composited into poly(ε-caprolactone) (PCL) and cast films of these polymers are evaluated for their antibacterial activities against Escherichia coli under light. While no antibacterial activity is observed when fluorescent light is used as the light source, activity is observed when simulated sunlight from a Xe lamp is used. The biodegradation rates of films with and without the gC3N4 photocatalyst are almost identical when immersed in the sea under dark conditions. However, films composited with the photocatalyst exhibit suppressed levels of biodegradation compared to those devoid of the photocatalyst when immersed under bright conditions, which suggests that the biodegradabilities of biodegradable polymers composited with the metal-free photocatalyst are suppressed due to the mild antibacterial activity of gC3N4 under sunlight. Accordingly, gC3N4 can potentially be used to control the biodegradation levels of biodegradable plastics in the marine environment.