Preparation of Silver Nanoparticles in Ultrasonic Vibration-Induced Nanodroplets of Isopropyl Alcohol in Combination with Ionic Liquids

Silver nanoparticles (< 10 nm) were prepared in ultrasonic vibration-induced nanodroplets of isopropyl alcohol (IPA) in combination with hydrophobic room temperature ionic liquids (RTILs). The Ag-precursor used were silver (I) complex, Ag(2)(ehac)(2)(eha)(2) (ehac = 2-ethylhexylammonium carbamate; eha = 2-ethylhexylamine), in IPA, while 1-butyl-3-methylimidazolium-based ionic liquids bearing SbF(6)(-), PF(6)(-) and NTf(2)(-) as counter anions were used as RTILs. During sonication for 10-90 min at room temperature, uniform silver nanoparticles with mean sizes of 2 to 8 nm were rapidly synthesized. Transmission electron micrographs also confirmed that silver nanoparticles have a spherical shape and diverse sizes depending on the reaction time (10-90 min).