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

ABSTRACT 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.