title: Stability and sedimentation of silver nanoparticles in the presence of monovalent, divalent and trivalent electrolyte solutions.
abstract: The present study seeks to elucidate the effect of different electrolytes on the stability of citrate-coated silver nanoparticles synthesized by the reduction of the Ag(NH3)(2)(+) complex via Tollens' method. Time-resolved dynamic light scattering technique was used to measure the aggregation behavior of the nanoparticles over a range of electrolyte (NaCl, CaCl₂, and AlCl₃) concentrations. From the aggregation kinetic data, the critical coagulation concentration values were calculated as 0.11, 1.7 × 10⁻³, and 5.06 × 10⁻⁶ M for NaCl, CaCl₂, and AlCl₃, respectively. Supernatant of the nanoparticle suspension in presence of the three electrolytes was collected and measured using inductively coupled plasma mass spectrometry to quantify the sedimentation. It was found that the silver nanoparticle aggregates settled rapidly in the slow aggregation and fast aggregation regimes. Their sedimentation followed a nanoparticle size-dependent manner.
authors: Department of Chemical Engineering, Maoming Polytechnic, Maoming, China.
authors: Shao-Feng
authors: SF
authors: Chen
authors: Department of Civil and Environmental Engineering, University of Rhode Island, Kingston, USA E-mail: hongyin1983@gmail.com.
authors: Hongyin
authors: H
authors: Zhang
mesh_terms: D011232:Chemical Precipitation; D002951:Citrates / Q000737:chemistry; D055664:Electrochemical Techniques; D004573:Electrolytes / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D002951:Citrates; D004573:Electrolytes; D012996:Solutions; D014874:Water Pollutants, Chemical; D012834:Silver