Preparation of colloidal molecules with temperature-tunable interactions from oppositely charged microgel spheres

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

The self-assembly of small colloidal clusters, so-called colloidal molecules, into crystalline materials has proven extremely challenging, the outcome often being glassy, amorphous states where positions and orientations are locked. In this paper, a new type of colloidal molecule is therefore prepared, assembled from poly(N-isopropylacrylamide) (PNIPAM)-based microgels that due to their well documented softness and temperature-response allow for greater defect tolerance compared to hard spheres and for convenient in situ tuning of size, volume fraction and inter-particle interactions with temperature. The microgels (B) are assembled by electrostatic adsorption onto oppositely charged, smaller-sized microgels (A), where the relative size of the two determines the valency (n) of the resulting core-satellite ABn-type colloidal molecules. Following assembly, a microfluidic deterministic lateral displacement (DLD) device is used to effectively isolate AB4-type colloidal molecules of tetrahedral geometry that possess a repulsive-to-attractive transition on crossing the microgels' volume phase transition temperature (VPTT). These soft, temperature-responsive colloidal molecules constitute highly promising building blocks for the preparation of new materials with emergent properties, and their optical wavelength-size makes them especially interesting for optical applications.

Detaljer

Författare
Enheter & grupper
Externa organisationer
  • Lund University
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Den kondenserade materiens fysik
Originalspråkengelska
Sidor (från-till)8512-8524
Antal sidor13
TidskriftSoft Matter
Volym15
Utgåva nummer42
StatusPublished - 2019 nov
PublikationskategoriForskning
Peer review utfördJa