Immobilization of Erythrosine Dye in Polysiloxane to Fabricate a Cost-effective Renewable Antibiotic Film through Visible Light-induced Singlet Oxygen Generation

Abstract

The advanced oxidation process (AOP) is the most effective strategy to remove volatile organic compounds that are considered to be one of the main pollutants adversely affecting the environment and human health. While metal-based semiconductors are widely considered as promising photocatalysts to remove pollutants through AOP systems, their low light absorption efficiency and poor processibility remain major issues to be utilized for a sustainable AOP system with low energy consumption. However, the organic dye, erythrosine, which can generate singlet oxygens by absorbing visible light, is considered an excellent substitute for metal-based photocatalysts for cheap renewable AOP systems. Accordingly, we here demonstrate a new hybrid membrane, wherein erythrosine molecules are embedded into films of polydimethylsiloxane. The polymeric networks therefore play an important role in enhancing the thermal stability and light absorption efficiency of dye molecules upon hybridization. In addition, the foamed structures of films to enhance their porosity and oxygen permeability are introduced via the fast evaporation of ethanol. As a result, the photocatalytic performance of dyes is significantly reinforced as the porosity of the membrane increases, which is proven by analyzing the degradation efficiency of 1,3–diphenylisobenzofuran with the presence of foamed and hybridized films. The photocatalytic ability of the formed hybrid films was well regenerated in three repeated recycles. Moreover, an optical parametric oscillator (OPO) laser system was used to successfully demonstrate that the singlet oxygen generated from the optimized hybrid film was well diffused into the surface of polymer matrix. Accordingly, the film could effectively sterilize S. aureus and E. coli in an aqueous solution. Therefore, this study suggests that the hybridization of polymer and dye without chemical modification can be an effective strategy to fabricate cheap and reusable porous membranes for a practical environment purification system.