This article presents an electrochemical discharge (ECD) method that consists of a combination of chemical methods and electric arc discharges. In the method, 140 V is applied to an Ag electrode from a DC power supply. The arc-discharge between the electrodes produces metallic silver nanoparticles and silver ions in the aqueous solution. Compared with the original arc discharge, this ECD method creates smaller nanoparticles, prevents clumping of the nanoparticles, and shortens the production time. The citrate ions also reduce the silver ions to silver nanoparticles. In addition, the citrate ions cap the surface of the produced silver nanoparticles and the zeta potential increases. In this article, the weight loss of the electrodes and the reduction of silver ions to silver nanoparticles as a function of citrate concentration and electric conductivity of the medium are discussed. Furthermore, the properties of the colloidal silver prepared with ECD are analyzed by UV–Vis spectroscopy, dynamic light scattering, electrophoresis light scattering, and scanning electron microscopy. Finally, a continuous production apparatus is presented for the continuous production of colloidal silver.
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Chak SK, Rao PV (2007) Trepanning of Al2O3 by electro-chemical discharge machining (ECDM) process using abrasive electrode with pulsed DC supply. Int J Mach Tools Manuf 47:2061–2070CrossRefGoogle Scholar
Cheng W, Dong S, Wang E (2002) Studies of electrochemical quantized capacitance charging of surface ensembles of silver nanoparticles. Electrochem Commun 4:412–416CrossRefGoogle Scholar
Henglein A, Giersig M (1999) Formation of colloidal silver nanoparticles: capping action of citrate. J Phys Chem B 103:9533–9539CrossRefGoogle Scholar
Jinno M, Bandow S, Ando Y (2004) Multiwalled carbon nanotubes produced by direct current arc discharge in hydrogen gas. Chem Phys Lett 398:256–259CrossRefGoogle Scholar
Liao YS, Huang JT, Chen YH (2004) A study to achieve a fine surface finish in Wire-EDM. J Mater Process Technol 149:165–171CrossRefGoogle Scholar
Lo C-H, Tsung T-T, Lin H-M (2007) Preparation of silver nanofluid by the submerged arc nanoparticle synthesis system (SANSS). J Alloys Compd 434:659–662CrossRefGoogle Scholar
Ozcan-Yilsay T, Lee W-J, Horne D, Lucey JA (2007) Effect of trisodium citrate on rheological and physical properties and microstructure of yogurt. J Dairy Sci 90:1644–1652CrossRefGoogle Scholar
Peças P, Henriques E (2008) Electrical discharge machining using simple and powder-mixed dielectric: the effect of the electrode area in the surface roughness and topography. J Mater Process Technol 200:250–258CrossRefGoogle Scholar
Pillai ZS, Kamat PV (2004) What factors control the size and shape of silver nanoparticles in the citrate ion reduction method? J Phys Chem B 108:945–951CrossRefGoogle Scholar
Schumacher BM (2004) After 60 years of EDM the discharge process remains still disputed. J Mater Process Technol 149:376–381CrossRefGoogle Scholar
Shin S-H, Ye M-K, Kim H-S, Kang H-S (2007) The effects of nano-silver on the proliferation and cytokine expression by peripheral blood mononuclear cells. Int Immunopharmacol 7:1813–1818CrossRefGoogle Scholar
Tarasenko NV, Butsen AV, Nevar EA (2005) Laser-induced modification of metal nanoparticles formed by laser ablation technique in liquids. Appl Surf Sci 247:418–422CrossRefGoogle Scholar
Tseng K-H, Liao C-Y, Huang J-C, Tien D-C, Tsung T-T (2008) Characterization of gold nanoparticles in organic or inorganic medium (ethanol/water) fabricated by spark discharge method. Mater Lett 62:3341–3344CrossRefGoogle Scholar
Zou X, Dong S (2006) Surface-enhanced raman scattering studies on aggregated silver nanoplates in aqueous solution. J Phys Chem B 110:21545–21550CrossRefGoogle Scholar