Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Environmental Chemistry Environmental Chemistry Society
Environmental problems - Chemical approaches
RESEARCH ARTICLE

Aggregation kinetics and surface charge of CuO nanoparticles: the influence of pH, ionic strength and humic acids

Vânia Serrão Sousa A and Margarida Ribau Teixeira A B
+ Author Affiliations
- Author Affiliations

A Center for Environmental and Sustainability Research (CENSE), University of Algarve, Faculty of Sciences and Technology, Building 7, Campus de Gambelas, PT-8005-139 Faro, Portugal.

B Corresponding author. Email: mribau@ualg.pt

Environmental Chemistry 10(4) 313-322 https://doi.org/10.1071/EN13001
Submitted: 2 January 2013  Accepted: 18 May 2013   Published: 5 August 2013

Environmental context. The high demand and use of nanomaterials in commercial products have led to increased concerns about their effect on the environment and human health. Because CuO nanoparticles are widely used in several products, it is necessary to understand and predict their behaviour and fate in the environment. We report a study on the aggregation and surface charge of CuO nanoparticles under environmentally relevant conditions to better predict the mobility and bioavailability of these materials in natural waters.

Abstract. In this study, the role of pH, ionic strength and humic acids (HAs) on the aggregation kinetics and surface charge of commercial copper oxide (CuO) nanoparticles were examined. Results show that the aggregation of CuO nanoparticles is favoured near pH 10, which was determined as the isoelectric point where the hydrodynamic diameter of the aggregates is the greatest. The aggregation of CuO nanoparticles is also ionic strength dependent. The increase in the ionic strength reduces the zeta potential, which leads to an increase in aggregation until 0.15 M. After this point an increase in ionic strength has no influence on aggregation. In the presence of HA for concentrations below 4 mg C L–1, aggregation was enhanced for acidic to neutral pH, whereas for higher concentrations, at all pH tested, aggregation does not change. The influence of HA on CuO nanoparticles is due to steric and electrostatic interactions. The sedimentation rates of CuO nanoparticles showed a relation between particle diameter and zeta potentials values confirmed by Derjaguin–Landau–Verwey–Overbeek calculations. The results obtained have important implications for predicting the stability and fate of CuO nanoparticles in natural water.

Additional keywords: copper oxide, DLVO theory, hydrodynamic diameter, sedimentation rate, zeta potential.


References

[1]  S. Klaine, P. Alvarez, G. Batley, T. Fernandes, R. Handy, D. Lyon, S. Mahendra, M. McLaughlin, J. Lead, Nanomaterials in the environment: behaviour, fate, bioavailability and effects. Environ. Toxicol. Chem. 2008, 27, 1825.
Nanomaterials in the environment: behaviour, fate, bioavailability and effects.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtVersLjJ&md5=6645abfd7ebb9ed401bd38dd5a08ba95CAS | 19086204PubMed |

[2]  J. Jiang, G. Oberdörster, P. Biwas, Characterization of size, surface charge, and agglomeration state of nanoparticles dispersions for toxicological studies. J. Nanopart. Res. 2009, 11, 77.
Characterization of size, surface charge, and agglomeration state of nanoparticles dispersions for toxicological studies.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhtlSksA%3D%3D&md5=5a32ad63e9767aebbb0adaabaaeb88d0CAS |

[3]  H. Karlsson, P. Cronholm, J. Gustafsson, L. Möller, Copper oxide nanoparticles are highly toxic: a comparison between metal oxide nanoparticles and carbpn nanotubes. Chem. Res. Toxicol. 2008, 21, 1726.
Copper oxide nanoparticles are highly toxic: a comparison between metal oxide nanoparticles and carbpn nanotubes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXpvFOht7Y%3D&md5=aa7d260c670f7f8962e9cf0ab856b496CAS | 18710264PubMed |

[4]  T. R. Society, Nanoscience and nanotechnologies: opportunities and uncertains 2004 (Clyvedon Press for The Royal Society and The Royal Academy of Engineering: Cardiff, UK). Available at http://www.raeng.org.uk/news/publications/list/reports/nanoscience_nanotechnologies.pdf [Verified 27 June 2013].

[5]  C. Pang, H. Selck, G. Banta, S. Misra, D. Berhanu, A. Dybowska, E. Valsami-Jones, V. Forbes, Bioaccumulation, toxicokinetics, and effects of copper from sediment spiked with aqueos Cu, nano-CuO or micro-CuO in the deposit-feeding snail, Potamopyrgus antipodarum. Environ. Toxicol. Chem. 2013, [Published online ahead of print 20 May 2013]
Bioaccumulation, toxicokinetics, and effects of copper from sediment spiked with aqueos Cu, nano-CuO or micro-CuO in the deposit-feeding snail, Potamopyrgus antipodarum.Crossref | GoogleScholarGoogle Scholar | 23471830PubMed |

[6]  B. Nowack, T. Bucheli, Occurrence, behavior and effects of nanoparticles in the environment. Environ. Pollut. 2007, 150, 5.
Occurrence, behavior and effects of nanoparticles in the environment.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXhtF2mt7vJ&md5=d01ae06cb084737eeca6af664d97b1cbCAS | 17658673PubMed |

[7]  M. Baalousha, Aggregation and disaggregation of iron oxide nanoparticles: influence of particle concentration, pH and natural organic matter. Sci. Total Environ. 2009, 407, 2093.
Aggregation and disaggregation of iron oxide nanoparticles: influence of particle concentration, pH and natural organic matter.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXit1Sjtb0%3D&md5=62bbb8d365cee60c845956065102b1c9CAS | 19059631PubMed |

[8]  J. Fabrega, S. Luoma, C. Tyler, T. Galloway, J. Lead, Silver nanoparticles: behaviour and effects in the aquatic environment. Environ. Int. 2011, 37, 517.
Silver nanoparticles: behaviour and effects in the aquatic environment.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhtFCjtr8%3D&md5=ed6fbfddda8287ca240c37a9d71a316dCAS | 21159383PubMed |

[9]  M. Baalousha, A. Manciulea, S. Cumberland, K. Kendall, J. Lead, Aggregation and surface properties of iron oxide nanoparticles: influence of pH and natural organic matter. Environ. Toxicol. Chem. 2008, 27, 1875.
Aggregation and surface properties of iron oxide nanoparticles: influence of pH and natural organic matter.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtVersLjF&md5=f5d8cb8beab0f24afdfaa4f14a2bc33aCAS | 19086206PubMed |

[10]  S. Mylon, K. L. Chen, M. Elimelech, Influence of natural organic matter and ionic composition on the kinetics and structure of hematite colloid aggregation: implications to iron depletion in estuaries. Langmuir 2004, 20, 9000.
Influence of natural organic matter and ionic composition on the kinetics and structure of hematite colloid aggregation: implications to iron depletion in estuaries.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXntlaltbo%3D&md5=a2d7ea1987e7fcc6f484b63bf1f71386CAS | 15461479PubMed |

[11]  Y. Zhang, Y. Chen, P. Westerhoff, J. Crittenden, Impact of natural organic matter and divalent cations on the stability of aqueous nanoparticles. Water Res. 2009, 43, 4249.
Impact of natural organic matter and divalent cations on the stability of aqueous nanoparticles.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhtFWks73O&md5=48c88c3191b62de57bd7ebcf8be78702CAS | 19577783PubMed |

[12]  A. Panacek, R. Prucek, D. Safarova, M. Dittrich, J. Richtrova, K. Benickova, R. Zboril, L. Kvitek, Acute and chronic toxicity effects of silver nanoparticles (NPs) on Drosophila melanogaster. Environ. Sci. Technol. 2011, 45, 4974.
Acute and chronic toxicity effects of silver nanoparticles (NPs) on Drosophila melanogaster.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXlslyitbs%3D&md5=bb00d22d46947abda9533e1651c03a7eCAS | 21553866PubMed |

[13]  Y. Wang, Y. Li, K. Pennell, Influence of electrolyte species and concentration on the aggregation and transport of fullerene naoparticles in quartz sands. Environ. Toxicol. Chem. 2008, 27, 1860.
Influence of electrolyte species and concentration on the aggregation and transport of fullerene naoparticles in quartz sands.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtVersLjL&md5=71bfb87adf6c4eafdb8b908328286704CAS | 19086205PubMed |

[14]  K. Chen, S. Mylon, M. Elimelech, Aggregation kinetics of alginate-coated hematite nanoparticles in monovalent and divalent electrolytes. Environ. Sci. Technol. 2006, 40, 1516.
Aggregation kinetics of alginate-coated hematite nanoparticles in monovalent and divalent electrolytes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XpsVGhtA%3D%3D&md5=5e773b7e00686494059cdc15a760c6cdCAS | 16568765PubMed |

[15]  I. Blinova, A. Ivask, M. Heinlaan, M. Mortimer, A. Kahru, Ecotoxicity of nanoparticles of CuO and ZnO in natural water. Environ. Pollut. 2010, 158, 41.
Ecotoxicity of nanoparticles of CuO and ZnO in natural water.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhsV2ksrzI&md5=3f825f0468667dff68cacd7207d84ecaCAS | 19800155PubMed |

[16]  C. Pang, H. Selck, S. Misra, D. Berhanu, A. Dybowska, E. Valsami-Jones, V. Forbes, Effects of sediment-associated copper to the deposit-feeding snail, Potamopyrgus antipodarum: a comparison of Cu added in aqueous form or as nano- and micro-CuO particles. Aquat. Toxicol. 2012, 106–107, 114.
Effects of sediment-associated copper to the deposit-feeding snail, Potamopyrgus antipodarum: a comparison of Cu added in aqueous form or as nano- and micro-CuO particles.Crossref | GoogleScholarGoogle Scholar | 22120004PubMed |

[17]  J. Zhao, Z. Wang, X. Liu, X. Xie, K. Zhang, B. Xing, Distribution of CuO nanoparticles in juvenile carp (Cyprinus carpio) and their potential toxicity. J. Hazard. Mater. 2011, 197, 304.
Distribution of CuO nanoparticles in juvenile carp (Cyprinus carpio) and their potential toxicity.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhsFWqsLbF&md5=0a1947f4170b76509308a414af4c83f7CAS | 22014442PubMed |

[18]  R. F. Domingos, N. Tufenkji, K. J. Wilkinson, Aggregation of titanium dioxide nanoparticles: role of a fulvic acid. Environ. Sci. Technol. 2009, 43, 1282.
Aggregation of titanium dioxide nanoparticles: role of a fulvic acid.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXotlKktA%3D%3D&md5=9681c1f29443e7159c33c2be7b9ae91fCAS | 19350891PubMed |

[19]  T. Gomes, J. Pinheiro, I. Cancio, C. Pereira, C. Cardoso, M. Bebianno, Effects of copper nanoparticles exposure in the mussel Mytilus galloprovinciallis. Environ. Sci. Technol. 2011, 45, 9356.
Effects of copper nanoparticles exposure in the mussel Mytilus galloprovinciallis.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXht1yhsLrM&md5=428ce4634187b3802229171f08e53300CAS | 21950553PubMed |

[20]  T. Gomes, C. G. Pereira, C. Cardoso, J. P. Pinheiro, I. Cancio, M. J. Bebianno, Accumulation and toxicity of copper oxide nanoparticles in the digestive gland of Mytilus galloprovincialis. Aquat. Toxicol. 2012, 118–119, 72.
Accumulation and toxicity of copper oxide nanoparticles in the digestive gland of Mytilus galloprovincialis.Crossref | GoogleScholarGoogle Scholar | 22522170PubMed |

[21]  A. D. Eaton, L. S. Clesceri, E. W. Rice, A. E. Greenberg, Standard Methods for the Examination of Water and Wastewater, 21st edn 2005 (American Public Health Association, American Water Works Association, and Water Environment Federation: Washington, DC).

[22]  S. Hong, M. Elimelech, Chemical and physical aspects of natural organic matter (NOM) fouling of nanofiltration membranes. J. Membr. Sci. 1997, 132, 159.
Chemical and physical aspects of natural organic matter (NOM) fouling of nanofiltration membranes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXksVamurc%3D&md5=cabe85c3e777644a8a25f39ba9734bcdCAS |

[23]  J. D. Hu, Y. Zevi, X.-M. Kou, J. Xiao, X.-J. Wang, Y. Jin, Effect of dissolved organic matter on the stability of magnetite nanoparticles under different pH and ionic strength conditions. Sci. Total Environ. 2010, 408, 3477.
Effect of dissolved organic matter on the stability of magnetite nanoparticles under different pH and ionic strength conditions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXntlOitb8%3D&md5=8f95f21c56832f66332166f7f7b01c1cCAS | 20421125PubMed |

[24]  S. Li, W. Sun, A comparative study on aggregation/sedimentation of TiO2 nanoparticles in mono- and binary systems of fulvic acids and FeIII. J. Hazard. Mater. 2011, 197, 70.
A comparative study on aggregation/sedimentation of TiO2 nanoparticles in mono- and binary systems of fulvic acids and FeIII.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhsFWqsb7F&md5=7655ba76ed834823cc19f370eec74352CAS | 22001572PubMed |

[25]  A. A. Keller, H. Wang, D. Zhou, H. S. Lenihan, G. Cherr, B. J. Cardinale, R. Miller, Z. Ji, Stability and aggregation of metal oxide nanoparticles in natural aqueous matrices. Environ. Sci. Technol. 2010, 44, 1962.
Stability and aggregation of metal oxide nanoparticles in natural aqueous matrices.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhvFWgtLk%3D&md5=0bcf43839222844347fce0dc022fe9efCAS | 20151631PubMed |

[26]  J. Gregory, Approximate expressions for retarded van der Waals interaction. J. Colloid Interface Sci. 1981, 83, 138.
Approximate expressions for retarded van der Waals interaction.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3MXltlyrs7o%3D&md5=795644676d53b9885556b88457c77402CAS |

[27]  Y.-H. Shih, W.-S. Liu, Y. F. Su, Aggregation of stabilised TiO2 nanoparticles suspensios in the presence of inorganic ions. Environ. Toxicol. Chem. 2012, 31, 1693.
Aggregation of stabilised TiO2 nanoparticles suspensios in the presence of inorganic ions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xhs1Gmtb7N&md5=41ea7a91b3a9ea75b7821c01e6a6ff1eCAS | 22639241PubMed |

[28]  R. A. French, A. R. Jacobson, B. Kim, S. L. Isley, R. L. Penn, P. C. Baveye, Influence of ionic strength, pH, and cation valence on aggregation kinetics of titanium dioxide nanoparticles. Environ. Sci. Technol. 2009, 43, 1354.
Influence of ionic strength, pH, and cation valence on aggregation kinetics of titanium dioxide nanoparticles.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXotlOksg%3D%3D&md5=12192d5c308281091f5155c972a31060CAS | 19350903PubMed |

[29]  S. Kim, K.-S. Lee, M. R. Zacharia, D. Lee, Three-dimensional off-lattice Monte Carlo simulations on a direct relation between experimental process parameters and fractal dimension of colloidal aggregates. J. Colloid Interface Sci. 2010, 344, 353.
Three-dimensional off-lattice Monte Carlo simulations on a direct relation between experimental process parameters and fractal dimension of colloidal aggregates.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXjtFKjsbs%3D&md5=79cc77ab1648c6cef0b3672fbd106a19CAS | 20132942PubMed |

[30]  B. D. Hall, D. Zanchet, D. Ugarte, Estimating nanoparticle size from diffraction measurements. J. Appl. Cryst. 2000, 33, 1335.
Estimating nanoparticle size from diffraction measurements.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXosFaktLY%3D&md5=3e9e4f01ee31936f36f6e2d9e095e55dCAS |

[31]  S. Calvin, S. X. Luo, C. Caragianis-Broadbridge, J. K. McGuinness, E. Anderson, A. Lehman, K. H. Wee, S. A. Morrisonb, L. K. Kurihara, Comparison of extended X-ray absorption fine structure and Scherrer analysis of X-ray diffraction as methods for determining mean sizes of polydisperse nanoparticles. Appl. Phys. Lett. 2005, 87, 233102.
Comparison of extended X-ray absorption fine structure and Scherrer analysis of X-ray diffraction as methods for determining mean sizes of polydisperse nanoparticles.Crossref | GoogleScholarGoogle Scholar |

[32]  D. Lee, J. Kim, B. G. Kim, A new parameter to control heat transport in nanofluids: surface charge state of the particle in suspension. J. Phys. Chem. B 2006, 110, 4320.

[33]  H. Chang, C. Jwo, C. Lo, T. Tsung, M. Kao, H. Lin, Rheology of CuO nanoparticle suspension prepared by ASNSS. Rev. Adv. Mater. Sci. 2005, 10, 128.
| 1:CAS:528:DC%2BD2MXhtVChurzI&md5=645cd49fffc22fc951b1820465043306CAS |

[34]  I. Morrison, S. Ross, Colloidal Dispersions: Suspensions, Emulsions and Foams 2002 (Wiley Interscience: New York).

[35]  F. von der Kammer, S. Ottofuelling, T. Hofmann, Assessment of the physico-chemical behavior of titanium dioxide nanoparticles in aquatic environments using multi-dimensional parameter testing. Environ. Pollut. 2010, 158, 3472.
Assessment of the physico-chemical behavior of titanium dioxide nanoparticles in aquatic environments using multi-dimensional parameter testing.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXht1Gjs7nN&md5=ab6149375b4682e592a6d5462b3fa9b6CAS | 20724049PubMed |

[36]  P. Narong, A. James, Effect of pH on the zeta potential and turbidity of yeast suspensions. Colloids Surf. A 2006, 274, 130.
Effect of pH on the zeta potential and turbidity of yeast suspensions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xotlamtg%3D%3D&md5=3d3a7d94e458572e32924a452b6b9eb9CAS |

[37]  D. Dickson, G. Liu, C. Li, G. Tachiev, Y. Cai, Dispersion and stability of bare hematite nanoparticles: effect of dispersion tools, nanoparticle concentration, humic acid and ionic strength. Sci. Total Environ. 2012, 419, 170.
Dispersion and stability of bare hematite nanoparticles: effect of dispersion tools, nanoparticle concentration, humic acid and ionic strength.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XisFWmtLY%3D&md5=29077a03f5796b4aec53928917d922c4CAS | 22289174PubMed |

[38]  S. Ottofuelling, F. Von der Kammer, T. Hofmann, Commercial titanium dioxide nanoparticles in both natural and synthetic water: comprehensive multidimensional testing and prediction of aggregation behavior. Environ. Sci. Technol. 2011, 45, 10045.
Commercial titanium dioxide nanoparticles in both natural and synthetic water: comprehensive multidimensional testing and prediction of aggregation behavior.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhtlCiurjM&md5=895c7d2c67041197b38361f488279ce6CAS | 22013881PubMed |

[39]  T. Phenrat, N. Saleh, K. Sirk, R. Tilton, G. Lowry, Aggregation and sedimentation of aqueous nanoscale zerovalent iron dispersions. Environ. Sci. Technol. 2007, 41, 284.
Aggregation and sedimentation of aqueous nanoscale zerovalent iron dispersions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhtlCit7nJ&md5=46127253feeaaaf6ac5cbfdd3f6d933fCAS | 17265960PubMed |

[40]  E. Illés, E. Tombacz, The effect of humic acid adsorption on pH-dependent surface charging and aggregation of magnetite nanoparticles. J. Colloid Interface Sci. 2006, 295, 115.
The effect of humic acid adsorption on pH-dependent surface charging and aggregation of magnetite nanoparticles.Crossref | GoogleScholarGoogle Scholar | 16139290PubMed |

[41]  M. Filella, J. Buffle, Factors controlling the stability of sub micron colloids in nature. Colloids Surf. A 1993, 73, 255.
Factors controlling the stability of sub micron colloids in nature.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXmslyisL8%3D&md5=649dad7aeaa2d5c389250d0ec42a03bcCAS |

[42]  K. Van Hoecke, K. A. C. Schamphelaere, P. Van der Meeren, G. Smagghe, C. R. Janssen, Aggregation and ecotoxicity of CeO2 nanoparticles in synthetic and natural waters with variable pH, organic matter concentration and ionic strength. Environ. Pollut. 2011, 159, 970.
Aggregation and ecotoxicity of CeO2 nanoparticles in synthetic and natural waters with variable pH, organic matter concentration and ionic strength.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhvFehsbc%3D&md5=854b982eb17243920208d4a4c9344b67CAS | 21247678PubMed |

[43]  M. Moore, Do nanoparticles present ecotoxicological risks for the health of the aquatic environment? Environ. Int. 2006, 32, 967.
Do nanoparticles present ecotoxicological risks for the health of the aquatic environment?Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhtFCqur3P&md5=5ef3415ce8ce9348e2ebcd4ef5b52a6eCAS | 16859745PubMed |

[44]  A. Baun, N. Hartmann, K. Grieger, K. Kusk, Ecotoxicity of engineered nanoparticles to aquatic invertebrates: a brief review and recommendations for future toxicity testing. Ecotoxicology 2008, 17, 387.
Ecotoxicity of engineered nanoparticles to aquatic invertebrates: a brief review and recommendations for future toxicity testing.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXmsVKrsbw%3D&md5=d45df6200362844a0938278f450643b2CAS | 18425578PubMed |