Plasmon-enhanced, two-photon absorption in Schiff-base-modified poly(styrene-co-maleic anhydride)–gold nanocomposites

Poly(styrene-co-maleic anhydride) (SMA) is a synthetic copolymer with interesting thermal and membrane properties. Schiff bases are one of the most widely used organic compounds with chelating ligands having N, S, and O as donor atoms. A Schiff-base-modified SMA was synthesized by the reaction of the copolymer with salicylaldehyde thiosemicarbazone. Gold (Au) nanoparticles (NPs), synthesized by a citrate reduction method were used to prepare the polymer–Au nanocomposites. In this research, we explored and investigated the effects on the linear and nonlinear optical properties of the Schiff-base-modified SMA copolymer with the incorporation of Au NPs. Open-aperture Z-scan measurements were recorded for the polymer, modified polymer, and polymer–Au nanocomposites at 532 nm with an Nd:YAG laser with a repetition rate of 10 Hz and a pulse width of 5 ns. The results indicate that the addition of the Au NPs effectively enhanced the two-photon absorption coefficients of the polymer and, thereby, provided a platform for the development of nonlinear optical devices with good optical-limiting properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45377.