Formation and Kinetics of Self-Assembled Structures of Magnetic Microparticles in Rotating Fields

Llera, María; Codnia, Jorge; Jorge, G. A.

doi:10.1109/tmag.2013.2257166

Cited by 9 publications

(7 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The actual pattern is selected from the application of an external magnetic field during the evaporation. This induces indeed a self-assembly of the particles [22][23][24][25][26][27][28][29][30][31][32][33] which is visible in the deposit. Following a quantitative description of the pattern obtained with homogeneous and constant field, we show that different patterns are produced by rotating and oscillating fields.…”

Section: Introductionmentioning

confidence: 95%

Remote-controlled deposit of superparamagnetic colloidal droplets

et al. 2018

View full text Add to dashboard Cite

Evaporation of sessile droplets is a way to organize suspended particles and create surface coating. Many studies have demonstrated that suspensions with various composition can give rise to qualitatively different dried patterns, often by focusing on the radial density profile of deposited particles. We demonstrate that a single suspension of superparamagnetic colloids can give rise to several dried patterns thanks to an external magnetic field applied during the evaporation process. We show the various patterns obtained with zero, constant, rotating and oscillating magnetic fields, and evidence the continuous control given by the intensity of a constant magnetic field. We also show this magnetic control has a substantial effect on the morphological details of the deposits.FIG. 1. Four deposits (four corners of the drop) obtained with different magnetic fields (null, homogeneous, rotating and oscillating fields, amplitude of non-zero magnetic fields are 22.5 G). Each picture has been numerically colorized, cropped as corner and positioned according to the corresponding field condition. The bottom picture is a zoom on the squared area. The global surface density of particles does not change very much. However, the morphological details of the deposit are radically different from one field to the other.

show abstract

Section: Introductionmentioning

confidence: 95%

Remote-controlled deposit of superparamagnetic colloidal droplets

et al. 2018

View full text Add to dashboard Cite

show abstract

“…The self-assembly of colloids is currently a topic of intensive research, both on fundamental [1][2][3][4][5][6][7][8][9][10][11] and applied aspects. [12][13][14][15][16][17][18][19][20][21][22] Amongst the self-assembly processes, the evaporation of colloidal droplets has attracted much interest due to its wide range of potential applications, extending from blood analysis [23][24][25][26] via inkjet printing, paint and polymers, [27][28][29] up to and including nanotechnology. [30] The main feature of colloidal droplets evaporation is the so-called coffee-ring effect.…”

Section: Introductionmentioning

confidence: 99%

Transitional bulk-solutal Marangoni instability in sessile drops

2018

View full text Add to dashboard Cite

Evaporation of sessile droplets is a method to organize suspended particles on solid substrates. Many studies have demonstrated that Marangoni flows caused by surface adsorbed molecules or temperature gradients can strongly affect the dried deposit. In the present paper, we show how transitional Marangoni instabilitiy can be triggered by bulk-diluted tensio-active ions. Thanks to PIV analysis, we identify four different flow stages. The transition between them can be understood by considering the competition between the Marangoni flow and the mass conservation flow, usually responsible for the coffee-ring pattern. We also demonstrate that the initial ionic concentration can select a coffee-ring pattern or a more homogeneous dried deposit.

show abstract

“…The formation of the filamentary structures in the uniaxial configuration has been previously studied by means of microscopic image analysis, in magnetic particles in a fluid [18,19], and non-magnetic particles in a magnetic fluid [20]. Previously, we have published a preliminary work as a conference proceeding, regarding this topic [21]. We have not found similar studies of more complicated geometries and field configurations.…”

Section: Introductionmentioning

confidence: 97%