Zero-valent iron nanoparticles rapidly aggregate. One of the reasons is magnetic forces among the nanoparticles. Magnetic field around particles is caused by composition of the particles. Their core is formed from zero-valent iron, and shell is a layer of magnetite. The magnetic forces contribute to attractive forces among the nanoparticles and that leads to increasing of aggregation of the nanoparticles. This effect is undesirable for decreasing of remediation properties of iron particles and limited transport possibilities. The aggregation of iron nanoparticles was established for consequent processes: Brownian motion, sedimentation, velocity gradient of fluid around particles and electrostatic forces. In our previous work, an introduction of influence of magnetic forces among particles on the aggregation was presented. These forces have significant impact on the rate of aggregation. In this article, a numerical computation of magnetic forces between an aggregate and a nanoparticle and between two aggregates is shown. It is done for random position of nanoparticles in an aggregate and random or arranged directions of magnetic polarizations and for structured aggregates with arranged vectors of polarizations. Statistical computation by Monte Carlo is done, and range of dominant area of magnetic forces around particles is assessed.

Technical University of Liberec Institute of Novel Technologies and Applied Informatics Liberec Czech Republic

Zobrazit více v PubMed

Zhang W-X. Nanoscale iron particles for environmental remediation: an overview. J Nanopart Res. 2003;5:323–332. doi: 10.1023/A:1025520116015. DOI

Li L, Fan M, Brown RC, Van Leeuwen J(H), Wang J, Wang W, Song Y, Zhang P. Synthesis, properties, and environmental applications of nanoscale iron-based materials. Rev Crit Rev Env Sci Technol. 2006;36:405–431. doi: 10.1080/10643380600620387. DOI

Nurmi JT, Tratnyek PG, Sarathy V, Baer DR, Amonette JE, Pecher K, Wang C, Linehan JC, Matson DW, Penn RL, Driessen MD. Characterization and properties of metallic iron nanoparticles: spectroscopy, electrochemistry and kinetics. Environ Sci Technol. 2005;39(5):1221–1230. doi: 10.1021/es049190u. PubMed DOI

Filip J, Zboril R, Schneeweiss O, Zeman J, Cernik M, Kvapil P, Otyepka M. Environmental applications of chemically pure natural ferrihydrite. Environ Sci Technol. 2007;41:4367–4374. doi: 10.1021/es062312t. PubMed DOI

Saleh N, Kim H-J, Phenrat T, Matyjaszewski K, Tilton RD, Lowry GV. Ionic strength and composition affect the mobility of surface-modified Fe0 nanoparticles in water-saturated sand columns. Environ Sci Technol. 2008;42(9):3349–3355. doi: 10.1021/es071936b. PubMed DOI

Johnson RL, Johnson GO, Nurmi JT, Tratnyek PG. Natural organic matter enhanced mobility of nano zerovalent Iron. Environ Sci Technol. 2009;43(14):5455–5460. doi: 10.1021/es900474f. PubMed DOI

Kanel SR, Grenche J-M, Choi H. Arsenic(V) removal from ground-water using nanoScale zero-valent iron as a colloidal reactive barrier material. Environ Sci Technol. 2006;40(6):2045–2050. doi: 10.1021/es0520924. PubMed DOI

Tiraferri A, Chen KL, Sethi R, Elimelech M. Reduced aggregation and sedimentation of zero-valent iron nanoparticles in the presence of guar gum. J Colloid Interface Sci. 2008;324:71–79. doi: 10.1016/j.jcis.2008.04.064. PubMed DOI

Kanel SR, Manning B, Charlet L, Choi H. Removal of Arsenic(III) from groundwater by nano scale zero-valent iron. Environ Sci Technol. 2005;39(5):1291–1298. doi: 10.1021/es048991u. PubMed DOI

Song H, Carraway ER. Reduction of chlorinated methanes by nano-sized zero-valent iron. Kinetics, pathways, and effect of reaction conditions. Environ Eng Sci. 2006;23(2):272–284. doi: 10.1089/ees.2006.23.272. PubMed DOI

Buffle J, Van Leeuwen H, Eds. Environmental Particles. Lewis Publishers 2, Boca Raton FL; 1993. pp. 353–360.

Somasundaran P, Runkana V. Modeling flocculation of colloidal mineral suspensions using population balances. Int J Min Process. 2003;72:33–55. doi: 10.1016/S0301-7516(03)00086-3. DOI

Garrick S, Zachariah M, Lehtinen K. Modeling and simulation of nanoparticle coagulation in high reynolds number incompressible flows. Proceeding of the National Conference of the Combustion Institute 25-27 2001; Oakland.

Thomas B, Camp R. Velocity gradients and internal work in fluid motion. J Boston Soc Civ Engi. 1943;30:4.

Smoluchowski MV. Test of a mathematical theory of coagulation kinetics of colloid solutions [in German] Zeitschrift F Physik Chemie. 1916;XCII:129–168.

Reardon EJ, Fagan R, Vogan JL, Przepiora A. Anaerobic corrosion reaction kinetics of nanosized iron. Environ Sci Technol. 2008;42(7):2420–2425. doi: 10.1021/es0712120. PubMed DOI

Horák D, Petrovský E, Kapička A, Frederichs T. Synthesis and characterization of magnetic poly(glycidyl methacrylate) microspheres. J Magn Magn Mater. 2007;311:500–506. doi: 10.1016/j.jmmm.2006.08.006. DOI

Masheva V, Grigorova M, Nihtianova D, Schmidt JE, Mikhov M. Magnetization processes of small γ-Fe2O3 particles in non-magnetic matrix. Phys D Appl Phys. 1999;32:1595–1599. doi: 10.1088/0022-3727/32/14/308. DOI

Phenrat T, Saleh N, Sirk K, Tilton RD, Lowry GV. Aggregation and sedimentation of aqueous nanoscale zerovalent iron dispersions. Environ Sci Technol. 2007;41(1):284–290. doi: 10.1021/es061349a. PubMed DOI

Zhang LY, Wang J, Wei LM, Liu P, Wei H, Zhang YF. Synthesis of Ni nanowires via a hydrazine reduction route in aqueous ethanol solutions assisted by external magnetic fields. Nano-Micro Lett. 2009;1:49–52.

Rosická D, Šembera J. Assessment of influence of magnetic forces on aggregation of zero-valent iron nanoparticles. Nanoscale Res Lett. 2010. PubMed PMC

Votrubík V. Theory of the Electromagnetic Field, [in Czech] Praha: Czechoslovak Academy of Science Publication; 1958.

Changes in the nanoparticle aggregation rate due to the additional effect of electrostatic and magnetic forces on mass transport coefficients