Modeling the Primary Size Effects of Citrate-Coated Silver Nanoparticles on Their Ion Release Kinetics

• Published in: Environmental science & technology Vol. 45; no. 10; pp. 4422 - 4428
• Main Authors: Zhang, Wen, Yao, Ying, Sullivan, Nicole, Chen, Yongsheng
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.05.2011
• Subjects: Animal, plant and microbial ecology; Applied ecology; Applied sciences; Aqueous solutions; Biological and medical sciences; Biological and physicochemical phenomena; Citric Acid - chemistry; Earth sciences; Earth, ocean, space; Ecotoxicology, biological effects of pollution; Engineering and environment geology. Geothermics; Environmental Modeling; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General aspects; Hydrogen-Ion Concentration; Ions; Ions - chemistry; Kinetics; Metal Nanoparticles - chemistry; Models, Chemical; Nanoparticles; Natural water pollution; Particle Size; Pollution; Pollution, environment geology; Salinity; Silver; Silver - chemistry; Temperature; Toxicity; Water Pollutants, Chemical - chemistry; Water treatment and pollution; Ecotoxicology; Pollutant behavior; Nanoparticle; Toxicity; Citrate; Environmental factor; Modeling; Heavy metal; Trace element; Aquatic environment; Silver; Environment impact; Size effect; Coated particle; Water pollution; Kinetics; Nanostructured materials
• ISSN: 0013-936X; 1520-5851; 1520-5851
• DOI: 10.1021/es104205a

Ion release is an important environmental behavior of silver nanoparticles (AgNPs), and characterization of Ag+ release is critical for understanding the environmental fate, transport, and biological impacts of AgNPs. The ion release kinetics of AgNPs with three primary diameters (20, 40, and 80 nm) were studied by dispersing them in quarter-strength Hoagland medium at two initial concentrations (300 and 600 μg/L). Ag+ release rates were found to depend on primary particle size and concentration, when other environmental factors (e.g., dissolved oxygen and protons) were kept constant. A kinetic model was developed to describe the Ag+ release based on the hard sphere theory using the Arrhenius equation. The model fitted the experimental data well with correlation coefficients of 0.97–0.99, and the model usefully interpreted the dependence of ion release kinetics on the primary particle size and concentration. Moreover, the effects of environmental factors (e.g., dissolved oxygen, pH, temperature, and salinity) potentially can be interpreted as well. This model provides fundamental insight into the ion release kinetics of AgNPs in aqueous environments, allowing us to better understand and predict the nanotoxicity of AgNPs.