Structure and Dynamics of Dense Colloidal Dispersions

 

Colloids are well-known model systems in respect to their analogy with simple phase diagram or for the investigation of the glass transition. It is however less clear for soft particles that are able to either interpenetrate and/or deform.

We are investigating the influence of the particle softness on the structure and dynamics of the dispersion and its repercussions across the colloidal glass and jamming transition and the resulting rheology of the dispersions.

 
  Fluid–solid transitions in soft-repulsive colloids Copyright: Crassous


Figure 1: Soft Matter Front Cover: Fluid–solid transitions in soft-repulsive colloids (Soft Matter, 2013, 9, 3000) [1].


Collaborations: Peter Schurtenberger (Lund University, Sweden), Emanuela Zaccareli (University La Sapienza, Rome, Italy), Priti Mohanti (KIIT University, Bhubaneswar, India).

 
 


The focus of many studies has now shifted towards anisotropic particles as they present a richer phase diagram and provide us with the possibility to control their orientation by applying an external field.

Reducing the orientational entropy, then may result in the formation of novel phases that we investigate by a combination of microscopy and scattering techniques. In particular, we are currently exploring the influence of shape anisotropy and applied external fields in dispersions of ellipsoidal or bowl-shaped particles and their repercussions on the colloidal phase behavior and dynamics

  Confocal micrograph Copyright: Crassous

Figure 2: Confocal micgrograph of a dense dispersion of composite ellipsoidal microgels.


Collaborations: Peter Schurtenberger (Lund University, Sweden), Antara Pal (Lund University, Sweden), Thiago Ito, Vincent Martinez (Edinburgh, Scotland), Janne-Mieke Meijer (Konstanz, Germany)

 
 


Video: „Dense bowl-shape responsive microgel dispersion“ [2]

Video: „Electric Field directed Assembly of Bowl-shape responsive microgel“ [2]

References
[1] D. Paloli, P. S. Mohanty, J. J. Crassous, E. Zaccarelli and P. Schurtenberger, Soft Matter, 2013, 9, 3000
[2] J. J. Crassous , A. M. Mihut , L. K. Månsson and Peter Schurtenberger, Nanoscale, 2015, 7, 15971