Splitting Regularities of Thin Ferrofluid Layer Manipulated by Vertical Magnetic Field
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摘要
The regular distribution of micro-droplets splitting from thin ferrofluid layer is systematic experimentally investigated, as the layer is placed in a vertical magnetic field. In this work, the field is applied in an instant manner and a slow manner, respectively; the field strength is linear increased. With instantly raising the field, it is observed that the ferrofluid layer is split into several regularly distributed micro-droplets, and that the number of micro-droplets is linear to the magnetic field strength and the thickness of the liquid layers. When the field is slowly increased, a liquid ring together with several micro-droplets appears from the ferrofluid layer splitting. A spatial drift of the micro-droplets is also observed in the process of increasing the magnetic field. Our results are useful for manipulating the splitting regularities of ferrofluid layers by magnetic field, which may be used in non-contact segmentation, and magnetically manipulated drug carriers for targeting the therapy, etc.
The regular distribution of micro-droplets splitting from thin ferrofluid layer is systematic experimentally investigated, as the layer is placed in a vertical magnetic field. In this work, the field is applied in an instant manner and a slow manner, respectively; the field strength is linear increased. With instantly raising the field, it is observed that the ferrofluid layer is split into several regularly distributed micro-droplets, and that the number of micro-droplets is linear to the magnetic field strength and the thickness of the liquid layers. When the field is slowly increased, a liquid ring together with several micro-droplets appears from the ferrofluid layer splitting. A spatial drift of the micro-droplets is also observed in the process of increasing the magnetic field. Our results are useful for manipulating the splitting regularities of ferrofluid layers by magnetic field, which may be used in non-contact segmentation, and magnetically manipulated drug carriers for targeting the therapy, etc.
The regular distribution of micro-droplets splitting from thin ferrofluid layer is systematic experimentally investigated, as the layer is placed in a vertical magnetic field. In this work, the field is applied in an instant manner and a slow manner, respectively; the field strength is linear increased. With instantly raising the field, it is observed that the ferrofluid layer is split into several regularly distributed micro-droplets, and that the number of micro-droplets is linear to the magnetic field strength and the thickness of the liquid layers. When the field is slowly increased, a liquid ring together with several micro-droplets appears from the ferrofluid layer splitting. A spatial drift of the micro-droplets is also observed in the process of increasing the magnetic field. Our results are useful for manipulating the splitting regularities of ferrofluid layers by magnetic field, which may be used in non-contact segmentation, and magnetically manipulated drug carriers for targeting the therapy, etc.
引文
[1]Li Y Q, Li X H. Influence of Perpendicular Magnetic Field on Apparent Density and Microstructure of Magnetic Fluid[J]. Chin. Phys. Lett.,2012, 29(10):107 501
[2]Rosensweig B E. Ferrohydrodynamics[M]. Cambridge:Cambridge University Press, 1985
[3]Genc S, Derin B. Synthesis and Rheology of Ferrofluids:A Review[J].Curr. Opin. Chem. Eng., 2014, 3(3):118-124
[4]Blums E, Cebers A, Maiorov M M. Magnetic Fluids[M]. New York:Walter de Gruyter, 1997
[5]Bergemann C, Muller D. Magnetic Ion-exchange Nano-and Microparticles for Medical, Biochemical and Molecular Biological Applications[J]. J. Magn. Magn. Mater., 1999, 194(1):45-52
[6]Schwertmann U, Cornell R M. The Iron Oxides[M]. Weinheim:Wiley-VCH Verlag GmbH, 2007
[7]Seo H S, Lee J C, Hwang I J, et al. Flow Characteristics of Ferrofluid in a Microchannel with Patterned Blocks[J]. Mater. Res. Bull., 2014,58(10):10-14
[8]Knieling H, Richter R. Growth of Surface Undulations at the Rosensweig Instability[J]. Phys. Rev. E, 2007, 76(2):066 301
[9]Cowley M D, Rosensweig R E. The Interfacial Stability of a Ferromagnetic Fluid[J]. J.Fluid Mech., 1968, 30(4), 671-688
[10]Lee C P,Yang S T, Wei Z H. Field Dependent Shape Variation of Magnetic Fluid Droplets on Magnetic Dots[J]. J. Magn. Magn. Mater.,2012, 324(24):4 133-4 135
[11]Chen C Y, Cheng Z Y. An Experimental Study on Rosensweig Instability of a Ferrofluid Droplet[J]. Phys. Fluids., 2008, 20(5):054 105
[12]Shi D, Bi Q. Experimental Investigation on Falling Ferrofluid Droplets in Vertical Magnetic Fields[J]. Exp. Therm. Fluid. SCI., 2014, 54:313-320
[13]Wu Y, Fu T. Ferrofluid Droplet Formation and Breakup Dynamics in a Microfluidic Flow-focusing Device[J]. Soft Matter, 2013, 9(41):9 792-9 798
[14]Greivell N E, Hannaford B. The Design of a Ferrofluid Magnetic Pipette[J]. IEEE T BIO-MED. ENG., 1997, 44(3):129-135
[15]Gollwitzer C, Matthies G. The Surface Topography of a Magnetic Fluid-a Quantitative Comparison between Experiment and Numerical Simulation[J]. J. Fluid Mech., 2006, 571(571):455-474
[16]Richter R, Barashenkov I V. Two-dimensional Solitons on the Surface of Magnetic Fluids[J]. Phys. Rev. Lett., 2005, 94(18):184 503
[17]Chen C Y, Lo L W. Breakup of Thin Films of Micro Magnetic Drops in Perpendicular Fields[J]. J.Magn.Magn.Mater., 2006, 305(2):440-447
[2]Rosensweig B E. Ferrohydrodynamics[M]. Cambridge:Cambridge University Press, 1985
[3]Genc S, Derin B. Synthesis and Rheology of Ferrofluids:A Review[J].Curr. Opin. Chem. Eng., 2014, 3(3):118-124
[4]Blums E, Cebers A, Maiorov M M. Magnetic Fluids[M]. New York:Walter de Gruyter, 1997
[5]Bergemann C, Muller D. Magnetic Ion-exchange Nano-and Microparticles for Medical, Biochemical and Molecular Biological Applications[J]. J. Magn. Magn. Mater., 1999, 194(1):45-52
[6]Schwertmann U, Cornell R M. The Iron Oxides[M]. Weinheim:Wiley-VCH Verlag GmbH, 2007
[7]Seo H S, Lee J C, Hwang I J, et al. Flow Characteristics of Ferrofluid in a Microchannel with Patterned Blocks[J]. Mater. Res. Bull., 2014,58(10):10-14
[8]Knieling H, Richter R. Growth of Surface Undulations at the Rosensweig Instability[J]. Phys. Rev. E, 2007, 76(2):066 301
[9]Cowley M D, Rosensweig R E. The Interfacial Stability of a Ferromagnetic Fluid[J]. J.Fluid Mech., 1968, 30(4), 671-688
[10]Lee C P,Yang S T, Wei Z H. Field Dependent Shape Variation of Magnetic Fluid Droplets on Magnetic Dots[J]. J. Magn. Magn. Mater.,2012, 324(24):4 133-4 135
[11]Chen C Y, Cheng Z Y. An Experimental Study on Rosensweig Instability of a Ferrofluid Droplet[J]. Phys. Fluids., 2008, 20(5):054 105
[12]Shi D, Bi Q. Experimental Investigation on Falling Ferrofluid Droplets in Vertical Magnetic Fields[J]. Exp. Therm. Fluid. SCI., 2014, 54:313-320
[13]Wu Y, Fu T. Ferrofluid Droplet Formation and Breakup Dynamics in a Microfluidic Flow-focusing Device[J]. Soft Matter, 2013, 9(41):9 792-9 798
[14]Greivell N E, Hannaford B. The Design of a Ferrofluid Magnetic Pipette[J]. IEEE T BIO-MED. ENG., 1997, 44(3):129-135
[15]Gollwitzer C, Matthies G. The Surface Topography of a Magnetic Fluid-a Quantitative Comparison between Experiment and Numerical Simulation[J]. J. Fluid Mech., 2006, 571(571):455-474
[16]Richter R, Barashenkov I V. Two-dimensional Solitons on the Surface of Magnetic Fluids[J]. Phys. Rev. Lett., 2005, 94(18):184 503
[17]Chen C Y, Lo L W. Breakup of Thin Films of Micro Magnetic Drops in Perpendicular Fields[J]. J.Magn.Magn.Mater., 2006, 305(2):440-447