THE SYNTHESIS OF Ag-POLYPYRROLE NANOCOMPOSITE COATED LATEX PARTICLES AND THEIR APPLICATION AS A FLUORESCENT QUENCHING AGENT

Submicron-sized Ag-polypyrrole/poly（styrene-co-methacrylic acid） （Ag-PPy/P（St-co-MAA）） composite particles were fabricated via a redox reaction between pyrrole and AgNO3 in the presence of P（St-co-MAA） soap-free latex. The products are characterized by transmission electron microscopy （TEM）, electron diffraction spectra （EDS）, Raman spectra, thermogravimetric analysis （TGA） and scanning electron microscopy （SEM）. The results showed that Ag-PPy nanocomposites were in situ deposited onto the surface of P（St-co-MAA） latex particles tailored by carboxylic-acid groups. The nanocomposites of Ag-PPy distributed on the surface of polymer particles transformed from discretely dots to continuously coating as the reaction temperature increased from 15℃ to 60℃. Strawberry-like composite particles were obtained at the reaction temperature of 60℃. The TGA characterization confirmed that the Ag-PPy nanocomposites loading onto the P（St-co-MAA） particles were systematically controlled over a range of 6 wt%-42 wt% by changing the reaction temperatures. The fluorescence quenching effect of the Ag-PPy/P（St-co-MAA） composite particles was explored on Rhodamine B as a model molecule with the Stern-Volmer quenching constant Ksv of 5.9 × 104 （g/mL）-1. It is suggested that the fluorescence quenching effect is caused by the resonance energy transfer mechanism.