Phase transfer of Au nanoparticles using one chemical inducer: DDAB

Au nanoparticles in aqueous medium were transferred to organic solution via a remarkably simple one-step route under the effect of phase transfer inducer dimethyldioctadecylammonium bromide (DDAB). The feature of our method is that only one reagent (DDAB) was added purposely for the phase transfer. This is different from the literatures, where two reagents were used for the phase transfer of Au nanoparticles. One is an Au nanoparticle stabilizer; the other is a phase transfer agent. The effect of the inducer DDAB concentration was checked, and it was found that the optimum concentration of DDAB was 1 × 10−5 mol dm−3 for phase transfer of Au nanoparticles. The organosol, Au nanoparticle, and phase transfer were characterized by UV–vis spectra, TEM, EDS, ED, and FT-IR. Molecular structure of quaternary ammonium salt was used to explain the unique effect of DDAB for the phase transfer of nanoparticles.