Facile strategy for preparing rhodamine B/ZrO2 composite fluorescent film with combined advantages of high emission intensity and outstanding water-resistance

• Methods to improve the water-resistance of RB/ZrO 2 fluorescence film were studied. • Rosin, OA and DTS are used as hydrophobic modifiers. • The optimized film has both favorable fluorescence property and water-resistance. • The film exhibits fluorescence stability under various aqueous environments. The RB/ZF composite film prepared by immobilizing rhodamine B (RB) on ZrO 2 film (ZF) exhibits strong fluorescence intensity but poor water-resistance. In this paper, rosin, octadecane-1, 18-dicarboxylic acid (OA) and silane coupling agent were used as hydrophobic modifiers to investigate the method to improve water-resistance of RB/ZF and maintain its strong fluorescence intensity as well. The influencing factors including modifier dosage, molecular structure, RB concentration and alkyl chain length of coupling agent on fluorescence performance and water-resistance of composite film were studied in detail and the related reasons were discussed. Results demonstrate that the film modified by the combination of rosin, OA and coupling agent has both favorable fluorescence performance and excellent water-resistance. The emission intensity of the optimized film is 94.5% of that of RB/ZF. Meanwhile, after immersion in various aqueous environments, there is no obvious difference in emission spectrum or intensity. Graphical Abstract .