Journal of Nanoparticle Research

, Volume 12, Issue 5, pp 1945–1958 | Cite as

Agglomeration, isolation and dissolution of commercially manufactured silver nanoparticles in aqueous environments

  • Sherrie Elzey
  • Vicki H. GrassianEmail author
Research Paper


The increasing use of manufactured nanoparticles ensures these materials will make their way into the environment. Silver nanoparticles in particular, due to use in a wide range of applications, have the potential to get into water systems, e.g., drinking water systems, ground water systems, estuaries, and/or lakes. One important question is what is the chemical and physical state of these nanoparticles in water? Are they present as isolated particles, agglomerates or dissolved ions, as this will dictate their fate and transport. Furthermore, does the chemical and physical state of the nanoparticles change as a function of size or differ from micron-sized particles of similar composition? In this study, an electrospray atomizer coupled to a scanning mobility particle sizer (ES-SMPS) is used to investigate the state of silver nanoparticles in water and aqueous nitric acid environments. Over the range of pH values investigated, 0.5–6.5, silver nanoparticles with a bimodal primary particle size distribution with the most intense peak at 5.0 ± 7.4 nm, as determined from transmission electron microscopy (TEM), show distinct size distributions indicating agglomeration between pH 6.5 and 3 and isolated nanoparticles at pH values from 2.5 to 1. At the lowest pH investigated, pH 0.5, there are no peaks detected by the SMPS, indicating complete nanoparticle dissolution. Further analysis of the solution shows dissolved Ag ions at a pH of 0.5. Interestingly, silver nanoparticle dissolution shows size dependent behavior as larger, micron-sized silver particles show no dissolution at this pH. Environmental implications of these results are discussed.


Silver nanoparticles Agglomeration Dissolution Acidic environments Environmental implications 



The authors would like to thank Dr. Jonas Baltrusaitis for the XPS analysis. Although the research described in this article has been funded wholly or in part by the Environmental Protection Agency through grant number EPA R83389101-0 to VHG, it has not been subjected to the Agency’s required peer and policy review and therefore does not necessarily reflect the views of the Agency and no official endorsement should be inferred. This research was also supported in part by the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program and by the Center for Health Effects of Environmental Contamination. CRIF equipment grant 0639096 from the National Science Foundation is also gratefully acknowledged.


  1. Agency for Toxic Substances and Disease Registry (ATSDR) (1990) Toxicological profile for silver. In: US Department of Health and Human Services, Public Health Service and Agency for Toxic Substances and Disease Registry (Eds). Atlanta, GAGoogle Scholar
  2. Alvarez PJ (2006) Nanotechnology in the environment—the good, the bad, and the ugly. J Environ Eng Asce 132(10):1233CrossRefGoogle Scholar
  3. Anselmann R (2001) Nanoparticles and nanolayers in commercial applications. J Nanopart Res 3(4):329–336CrossRefGoogle Scholar
  4. Asharani PVN, Gong ZY, Hande MP, Valiyaveettil S (2007) Potential health impacts of silver nanoparticles. Chem Res Toxicol 20(12):99Google Scholar
  5. Asharani PV, Wu YL, Gong ZY, Valiyaveettil S (2008) Toxicity of silver nanoparticles in zebrafish models. Nanotechnology 19(25):5102–5109CrossRefGoogle Scholar
  6. Becher P, Schuster D (1983) Encyclopedia of emulsion technology: basic theory, measurement, applications, vol 1. M. Dekker, New YorkGoogle Scholar
  7. Benn TM, Westerhoff P (2008) Nanoparticle silver released into water from commercially available sock fabrics. Environ Sci Technol 42(11):4133–4139CrossRefPubMedGoogle Scholar
  8. Borm P, Klaessig FC, Landry TD, Moudgil B, Pauluhn J, Thomas K, Trottier R, Wood S (2006) Research strategies for safety evaluation of nanomaterials. Part V. Role of dissolution in biological fate and effects of nanoscale particles. Toxicol Sci 90(1):23–32CrossRefPubMedGoogle Scholar
  9. Bottger PHM, Bi Z, Adolph D, Dick KA, Karlsson LS, Karlsson MNA, Wacaser BA, Deppert K (2007) Electrospraying of colloidal nanoparticles for seeding of nanostructure growth. Nanotechnology 18(10):5304–5309CrossRefGoogle Scholar
  10. Chen KL, Elimelech M (2006) Aggregation and deposition kinetics of fullerene (C-60) nanoparticles. Langmuir 22(26):10994–11001CrossRefPubMedGoogle Scholar
  11. Chen KL, Elimelech M (2007) Influence of humic acid on the aggregation kinetics of fullerene (C-60) nanoparticles in monovalent and divalent electrolyte solutions. J Colloid Interf Sci 309(1):126–134CrossRefGoogle Scholar
  12. Chen X, Schluesener HJ (2008) Nanosilver: a nanoproduct in medical application. Toxicol Lett 176(1):1–12CrossRefPubMedGoogle Scholar
  13. Chen Y, Wang CG, Ma ZF, Su ZM (2007) Controllable colours and shapes of silver nanostructures based on pH: application to surface-enhanced Raman scattering. Nanotechnology 18(32):5602–5606Google Scholar
  14. Cwiertny DM, Baltrusaitis J, Hunter GJ, Laskin A, Scherer MM, Grassian VH (2008). Characterization and acid-mobilization study of iron-containing mineral dust source materials. J Geophys Res 113(D05202). doi: 10.1029/2007JD009332
  15. Doumanidis H (2002) The Nanomanufacturing programme at the National Science Foundation. Nanotechnology 13(3):248–252CrossRefADSGoogle Scholar
  16. Eckelman MJ, Graedel TE (2007) Silver emissions and their environmental impacts: a multilevel assessment. Environ Sci Technol 41(17):6283–6289CrossRefPubMedGoogle Scholar
  17. Emerich DF, Thanos CG (2003) Nanotechnology and medicine. Expert Opin Biol Therapy 3(4):655–663CrossRefGoogle Scholar
  18. Falkenhagen D (1995) Small particles in medicine. Artif Organs 19(8):792–794CrossRefPubMedGoogle Scholar
  19. Fornes JA (1985) Secondary minimum analysis in the DLVO-theory. Colloid Polym Sci 263(12):1004–1007CrossRefGoogle Scholar
  20. Frank BP, Saltiel S, Hogrefe O, Grygas J, Lala GG (2008) Determination of mean particle size using the electrical aerosol detector and the condensation particle counter: comparison with the scanning mobility particle sizer. J Aerosol Sci 39(1):19–29CrossRefGoogle Scholar
  21. Gao XY, Wang SY, Li J, Zheng YX, Zhang RJ, Zhou P, Yang YM, Chen LY (2004) Study of structure and optical properties of silver oxide films by ellipsometry, XRD and XPS methods. Thin Solid Films 455:438–442CrossRefADSGoogle Scholar
  22. Grassian VH (2008) When size really matters: size-dependent properties and surface chemistry of metal and metal oxide nanoparticles in gas and liquid phase environments. J Phys Chem C 112(47):18303–18313Google Scholar
  23. Grassian VH (2009) New directions: nanodust—a source of metals in the atmospheric environment? Atmos Environ 43(30):4666–4667CrossRefGoogle Scholar
  24. Griffitt RJ, Luo J, Gao J, Bonzongo JC, Barber DS (2008) Effects of particle composition and species on toxicity of metallic nanomaterials in aquatic organisms. Environ Toxicol Chem 27(9):1972–1978CrossRefPubMedGoogle Scholar
  25. Gupta RB, Kompella UB (2006) Physical characterization of nanoparticles. In: Gupta RB, Kompella UB (eds) Nanoparticle technology for drug delivery. Taylor & Francis Group, New York, p 109Google Scholar
  26. Guzman KAD, Taylor MR, Banfield JF (2006) Environmental risks of nanotechnology: national nanotechnology initiative funding, 2000–2004. Environ Sci Technol 40(5):1401–1407CrossRefPubMedGoogle Scholar
  27. Howe PD, Dobson S (2002) Silver and silver compounds: environmental aspects. In: United Nations Environment Programme, International Labour Organization, World Health Organization and Inter-Organization Programme for the Sound Management of Chemicals (Eds), GenevaGoogle Scholar
  28. Huang F, Gilbert B, Zhang HH, Banfield JF (2004) Reversible, surface-controlled structure transformation in nanoparticles induced by an aggregation state. Phys Rev Lett 92(15):5501.1–5501.4Google Scholar
  29. Kuchibhatla SV, Karakoti AS, Seal S (2008) Colloidal stability by surface modification. J Miner Met Mater Soc 57(12):52–56Google Scholar
  30. Lecoanet HF, Bottero JY, Wiesner MR (2004) Laboratory assessment of the mobility of nanomaterials in porous media. Environ Sci Technol 38(19):5164–5169CrossRefPubMedGoogle Scholar
  31. Lowe T (2002) The revolution in nanometals. Adv Mater Process 160(1):63–65Google Scholar
  32. Lubick N (2008) Nanosilver toxicity: ions, nanoparticies-or both? Environ Sci Technol 42(23):8617CrossRefPubMedGoogle Scholar
  33. Luoma SN (2008) Silver nanotechnologies and the environment: old problems or new challenges? Woodrow Wilson International Center for Scholars, WashingtonGoogle Scholar
  34. Maynard AD (2006) Nanotechnology: a research strategy for addressing risk. Woodrow Wilson International Center for Scholars, WashingtonGoogle Scholar
  35. McAllister K, Sazani P, Adam M, Cho MJ, Rubinstein M, Samulski RJ, DeSimone JM (2002) Polymeric nanogels produced via inverse microemulsion polymerization as potential gene and antisense delivery agents. J Am Chem Soc 124(51):15198–15207CrossRefPubMedGoogle Scholar
  36. Meskhidze N, Chameides WL, Nenes A, Chen G (2003) Iron mobilization in mineral dust: Can anthropogenic SO2 emissions affect ocean productivity? Geophys Res Lett 30(21):2085CrossRefADSGoogle Scholar
  37. Meskhidze N, Chameides WL, Nenes A (2005) Dust and pollution: a recipe for enhanced ocean fertilization? J Geophys Res 110:D03301CrossRefGoogle Scholar
  38. Moskovits M, Vlckova B (2005) Adsorbate-induced silver nanoparticle aggregation kinetics. J Phys Chem B 109(31):14755–14758CrossRefPubMedGoogle Scholar
  39. Mueller NC, Nowack B (2008) Exposure modeling of engineered nanoparticles in the environment. Environ Sci Technol 42(12):4447–4453CrossRefPubMedGoogle Scholar
  40. Navarro E, Piccapietra F, Wagner B, Marconi F, Kaegi R, Odzak N, Sigg L, Behra R (2008) Toxicity of silver nanoparticles to Chlamydomonas reinhardtii. Environ Sci Technol 42(23):8959–8964CrossRefPubMedGoogle Scholar
  41. Oberdorster G, Maynard A, Donaldson K, Castranova V, Fitzpatrick J, Ausman K, Carter J, Karn B, Kreyling W, Lai D, Olin S, Monteiro-Riviere N, Warheit D, Yang H (2005) Principles for characterizing the potential human health effects from exposure to nanomaterials: elements of a screening strategy. Part Fibre Toxicol 2:8CrossRefPubMedGoogle Scholar
  42. Ozmetin C, Copur M, Yartasi A, Kocakerim MM (2000) Kinetic investigation of reaction between metallic silver and nitric acid solutions. Chem Eng Technol 23(8):707–711CrossRefGoogle Scholar
  43. Panyala NR, Pena-Mendez EM, Havel J (2008) Silver or silver nanoparticles: a hazardous threat to the environment and human health? J Appl Biomed 6(3):117–129Google Scholar
  44. Pease LF, Tsai DH, Zangmeister RA, Zachariah MR, Tarlov MJ (2007) Quantifying the surface coverage of conjugate molecules on functionalized nanoparticles. J Phys Chem C 111:17155–17157CrossRefGoogle Scholar
  45. Pettibone JB, Elzey S, Grassian VH (2008) An integrated approach toward understanding the environmental fate, transport, toxicity and health hazards of nanomaterials. In: Grassian VH (ed) Nanoscience and nanotechnology: environmental and health impacts. Wiley, Hoboken, p 47Google Scholar
  46. Powers KW, Brown SC, Krishna VB, Wasdo SC, Moudgil BM, Roberts SM (2006) Research strategies for safety evaluation of nanomaterials. Part VI. Characterization of nanoscale particles for toxicological evaluation. Toxicol Sci 90(2):296–303CrossRefPubMedGoogle Scholar
  47. Richardson SD (2007) Water analysis: emerging contaminants and current issues. Anal Chem 79(12):4295–4323CrossRefPubMedGoogle Scholar
  48. Sadrnezhaad SK, Ahmadi E, Mozammel M (2006) Kinetics of silver dissolution in nitric acid from Ag-AU(0.04)-CU0.10 and Ag–Cu-0.23 scraps. J Mater Sci Technol 22(5):696–700Google Scholar
  49. Schneider T, Jensen KA (2008) Combined single-drop and rotating drum dustiness test of fine to nanosize powders using a small drum. Ann Occup Hyg 52(1):23–34CrossRefPubMedGoogle Scholar
  50. Shin W, Wang J, Mertler M, Sachweh B, Fissan H, Pui D (2009) Structural properties of silver nanoparticle agglomerates based on transmission electron microscopy: relationship to particle mobility analysis. J Nanopart Res 11(1):163–173CrossRefGoogle Scholar
  51. Skebo JE, Grabinski CM, Schrand AM, Schlager JJ, Hussain SM (2007) Assessment of metal nanoparticle agglomeration, uptake, and interaction using high-illuminating system. Int J Toxicol 26(2):135–141CrossRefPubMedGoogle Scholar
  52. Suh J, Han B, Okuyama K, Choi M (2005) Highly charging of nanoparticles through electrospray of nanoparticle suspension. J Colloid Interf Sci 287(1):135–140CrossRefGoogle Scholar
  53. Tinke AP, Govoreanu R, Vanhoutte K (2006) Particle size and shape characterization of nano and submicron liquid dispersions. Am Pharm Rev 9(6):1–5Google Scholar
  54. Tsai CJ, Wu CH, Leu ML, Chen SC, Huang CY, Tsai PJ, Ko FH (2009) Dustiness test of nanopowders using a standard rotating drum with a modified sampling train. J Nanopart Res 11(1):121–131CrossRefGoogle Scholar
  55. TSI I. (2008) Real-time measurement of nanoparticle size distributions using electrical mobility technique. Vol. Application Note SMPS-004Google Scholar
  56. U. S. Environmental Protection Agency (2006) High production volume information system (HPVIS). In: U.S.E.P. Agency (Ed)Google Scholar
  57. Wada Y, Totoki S, Watanabe M, Moriya N, Tsunazawa Y, Shimaoka H (2006) Nanoparticle size analysis with relaxation of induced grating by dielectrophoresis. Optics Express 14(12):5755–5764CrossRefPubMedADSGoogle Scholar
  58. Wiesner MR, Lowry GV, Alvarez P, Dionysiou D, Biswas P (2006) Assessing the risks of manufactured nanomaterials. Environ Sci Technol 40(14):4336–4345CrossRefPubMedGoogle Scholar
  59. Wijnhoven SWP, Peijnenburg WJGM, Herberts CA, Hagens WI, Oomen AG, Heugens EHW, Roszek B, Bisschops J, Gosens I, Van De Meent D, Dekkers S, De Jong WH, van Zijverden M, Sips AJAM, Geertsma RE (2009) Nano-silver—a review of available data and knowledge gaps in human and environmental risk assessment. Nanotoxicology 3(2):109–138CrossRefGoogle Scholar
  60. Xu RL (2008) Progress in nanoparticles characterization: Sizing and zeta potential measurement. Particuology 6(2):112–115CrossRefGoogle Scholar
  61. Zelenyuk A, Cai Y, Imre D (2006) From agglomerates of spheres to irregularly shaped particles: determination of dynamic shape factors from measurements of mobility and vacuum aerodynamic diameters. Aerosol Sci Technol 40(3):197–217CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Department of Chemical and Biochemical EngineeringUniversity of IowaIowa CityUSA
  2. 2.Department of ChemistryUniversity of IowaIowa CityUSA
  3. 3.Nanoscience and Nanotechnology InstituteUniversity of IowaIowa CityUSA

Personalised recommendations