Path-Dependent Self-Assembly of Magnetic Anisotropic Colloidal Peanuts

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

Here we present the field induced self-assembly of anisotropic colloidal particles whose shape resembles peanuts. Being made up of hematite core and silica shell, these particles align in a direction perpendicular to the applied external magnetic field. Using small-angle X-ray scattering with microradian resolution (μrad-SAXS) in sedimented samples, we have found that one can tune the self-assembled structures by changing the time of application of the external field. If the field is applied after the sedimentation, the self-assembled structure is a nematic one, while dipolar chains are formed if the field is applied during the sedimentation process. Interestingly, within each chain particles form a smectic phase with defects. Further, these aforementioned nematic and smectic phases are of oblate type in spite of the prolate shape of the individual particles. For dipolar chains, an unusual diffraction peak shape has been observed with highly anisotropic tails in the transverse direction (perpendicular to the external field). The peak shape can be rationalized by considering the fact that the dipolar chains can act as a building block aligned along the field direction to form a para-nematic phase.

Detaljer

Författare
Enheter & grupper
Externa organisationer
  • Aix-Marseille University
  • Utrecht University
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Fysikalisk kemi
Originalspråkengelska
Sidor (från-till)5754-5760
Antal sidor7
TidskriftJournal of Physical Chemistry B
Volym124
Utgåva nummer27
StatusPublished - 2020 jul 9
PublikationskategoriForskning
Peer review utfördJa