Experimental evidence of dimer disruption in ionic ferrofluid:

Equilibrium structure of ferrofluid aggregates

“…The structural phase diagram we found could help to experimentally control the aggregation of magnetic particles. Further theoretical efforts are needed in order to incorporate temperature effects [16] and kinetic components in our model.…”

Time-modulation of surface functionalization in biocompatible magnetic fluids

“…However, desorption is a typical colloidal aging process which is closely related to nanoparticle clusterization, the latter tightening single nanoparticle units together in more complex agglomerates [1]. Cluster formation in MF samples, induced either by the application of an external magnetic field [2], reducing the MF sample temperature [3], increasing the MF nanoparticle concentration [4] or by changing the characteristics of the nanoparticle surface molecular layer [5][6][7][8][9], has been investigated to some extend though little effort has been devoted to understand the molecular surfacedesorption process that may leads to nanoparticle clusterization. The influence of the surface grafting on the MF properties has been investigated using for instance static magnetic measurements [5], magnetic resonance [6], optical transmission experiments [7], static magnetic birefringence [8], and photoacoustic spectroscopy [9].…”

Evidence of phase separation in magnetic colloids using magnetic resonance

“…The sample was frozen down to 100 K at zero-field-frozen condition with the measurements performed increasing the temperature. Features in the MR spectra had been discussed in terms of dimers and isolated particles, as discussed in the literature [1][2][3]. In fact, the pre-existence of such structures in MFs had been recently observed using cryogenic electron microscopy [17,18], and had also been related to the static magnetic birefringence of MFs [19][20][21].…”

“…r Magnetic resonance (MR) has been widely used to investigate magnetic fluids (MFs), especially under frozen (field-frozen and zero-field-frozen) conditions when it presents the framework of a three-dimensional nanoparticle-based system [1][2][3][4][5][6][7]. Even at room temperature MR has been used in the investigation of MFs, with special emphasis on surface charge-discharge processes [8] and the formation of agglomerates [1][2][3]. Several parameters can be easily controlled, with particular interest on the mean particle-particle distance which models the dipole-dipole interaction strength.…”

“…Even at room temperature MR has been used in the investigation of MFs, with special emphasis on surface charge-discharge processes [8] and the formation of agglomerates [1][2][3]. Several parameters can be easily controlled, with particular interest on the mean particle-particle distance which models the dipole-dipole interaction strength.…”