Shape anisotropic colloids: synthesis, packing behavior, evaporation driven assembly, and their application in emulsion stabilization

Abstract

The recent surge to explore and exploit the effect of particle shape has led to several interesting and unique observations in various diverse fields, ranging from biology to material science. To this end, the development of novel synthesis methods has contributed immensely, and has directed this exciting research on the role of particle shape in colloidal systems and other diverse fields. Furthermore, such investigations have resulted in the development of advanced materials, which are novel and multifunctional. In this article, we review recent advances in the study of suspensions containing shape anisotropic particles. In particular, we investigate those pertaining to rod-like or ellipsoidal particles and highlight recent results in three areasevaporation driven assembly, packing, interfacial behavior and the use of these particles in emulsion stabilization.

Droplets of cellulose nanocrystal suspensions on drying give iridescent 3-D “coffee-stain” rings

“…The surface self-assembly generated by this process has been extensively investigated for spherical particles, but less attention has been paid to suspensions of shape-anisotropic particles (Dugyala et al 2013). Examples of rod-like species forming ordered structures by evaporation of suspensions include the selfassembly of semiconductor nanorods (Querner et al 2008;Nobile et al 2009).…”

Evaporative gold nanorod assembly on chemically stripe-patterned gradient surfaces

“…properties from those of the individual composing elements [1][2][3][4][5][6][7]. The bottom-up approach to design and manufacture novel nanoscale materials has rapidly matured over the past years.…”

Polarized Raman scattering and SEM combined full characterization of self-assembled nematic thin films

“…20,23,35 In dip coating structure formation is triggered by the interplay of convective assembly in the capillary regime and shear forces in the intermediate and viscous drag regime. 9,19,[36][37][38] A flip from a parallel orientation of nanorods with respect to the contact line in the capillary regime to a perpendicular orientation of nanorods with respect to the contact line in the intermediate and viscous drag regime is observed. Interestingly, we observe for the first time a reorientation of the nanorods within the layer formed in the capillary regime.…”

“…8 Solution based deposition methods for shape anisotropic particles are for example drop casting, spin coating or Langmuir-Blodgett-type deposition. [9][10][11][12] However, all these methods lack control or uniformity over a large scale. In other words, there is no simple adjustment parameter to tune the properties of the resulting thin film.…”