The adsorbed species on nanofillers is one of the most important factors that may influence the performance
of polymer nanocomposites. Herein, we performed a systematic investigation of the effects of
the residual surfactant introduced by a synthetic method on the glass transition temperature (Tg) of
polystyrene/gold nanoparticle nanocomposites. The surfactant was found to cause an obvious decrease in
the Tg of polystyrene confined on gold. Furthermore, we used dipolar-filtered 1H solid-state nuclear
magnetic resonance to characterize the mobility of the molecules confined on gold. It was impossible to
completely remove the surfactant once it had been adsorbed on the gold nanoparticles; thus it is
important to choose suitable methods of synthesis, and special attention should be paid to the adsorbed
species on nanofillers