The preparation of hydrophobic silver nanoparticles via solvent exchange method

We have prepared hydrophobic silver nanoparticles capped by oleic acid via solvent exchange method. AgNO3 was reduced by NaBH4 to produce Ag nanoparticles in aqueous solution with various pH conditions and oleic acid as stabilizer. By the addition of H3PO4, the carboxylate group was converted to carboxylic acid, and this induced the reorientation of oleic acid, and provided hydrophobic silver nanoparticles. The oleic acid-capped silver nanoparticles were characterized by UV–vis spectrophotometer and Fourier transfer infrared spectrometer (FTIR). Spherical silver particles with uniform size of 8 nm were obtained from silver nitrate under basic aqueous solution.