Brij-micelle and polyacrylic acid interaction investigated by Cu2+-induced pyrene fluorescence: Effect of brij-micelle structure

Fluorescence response of pyrene has been studied in the presence of polyacrylic acid (PAA) and brij surfactant micelles with Cu2+ as an ionic quencher. The quenched pyrene emission is completely recovered with the addition of PAA (conc. 2.4 × 10−4 M) for brij 35 (poly-oxyethylene-23 lauryl ether) micelle indicating PAA–Cu2+ complex formation at the micelle–water interface. This could be due to the relatively easier accessibility of PAA polymer chains near poly-oxyethylene chain of brij 35 micelle compared to brij 30 (poly-oxyethylene-4 lauryl ether) micelle. The interaction between brij-micelle and polymer is confirmed by turbidimetry and NMR spectroscopy.