• Nomor Steve Aondoakaa
  Department of Chemistry, Rev. Fr. Moses Orshio Adasu University Makurdi, Nigeria
  




• Horrocks Benjamin Richard
  Department of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
  

Silver nanoparticles (AgNPs) were prepared by the citrate reduction method in pure water. They were infused with and dialysed against various concentrations of chloride and sulphate salts to determine the effect of the medium on the release of Ag(I). The AgNPs were characterised by UV-Vis spectrometry, dynamic light scattering (DLS) and atomic force microscopy (AFM), while the concentration of Ag(I) ions released was monitored by anodic stripping voltammetry (ASV). The mean hydrodynamic diameters of AgNPs as measured by DLS ranged from 100 nm in the 10 mmol chloride before dialysis to 890 nm in the 50 mmol sample after dialysis. In general, the increase was due to aggregation. Individual particle sizes as measured by AFM decreased after dialysis; this suggests corrosion of the AgNPs. The release of Ag(I) as monitored by anodic stripping voltammetry at glassy carbon electrodes revealed that: (i) substantial (90 mmol) Ag(I) was present in the initial preparation and (ii) the concentration of Ag(I) after 73h of dialysis was about 4 µmol irrespective of the concentration of chloride present. Presence of sulphates, however, did not prove to exert significant influence on the release of Ag(I) ions from a product or substrate to which they have been incorporated. The findings in this research are important in the study of the fate of AgNPs in marine environments.