Advanced

Reversible Formation of Thermoresponsive Binary Particle Gels with Tunable Structural and Mechanical Properties

Immink, Jasper LU ; Maris, Erik; Crassous, Jérôme; Stenhammar, Joakim LU and Schurtenberger, Peter LU (2019) In ACS Nano
Abstract
We investigate the collective behavior of suspended thermoresponsive microgels that expel solvent and subsequently decrease in size upon heating. Using a binary mixture of differently thermoresponsive microgels, we demonstrate how distinctly different gel structures form, depending on the heating profile used. Confocal laser scanning microscopy (CLSM) imaging shows that slow heating ramps yield a core–shell network through sequential gelation, while fast heating ramps yield a random binary network through homogelation. Here, secondary particles are shown to aggregate in a monolayer fashion upon the first gel, which can be qualitatively reproduced through Brownian dynamics simulations using a model based on a temperature-dependent... (More)
We investigate the collective behavior of suspended thermoresponsive microgels that expel solvent and subsequently decrease in size upon heating. Using a binary mixture of differently thermoresponsive microgels, we demonstrate how distinctly different gel structures form, depending on the heating profile used. Confocal laser scanning microscopy (CLSM) imaging shows that slow heating ramps yield a core–shell network through sequential gelation, while fast heating ramps yield a random binary network through homogelation. Here, secondary particles are shown to aggregate in a monolayer fashion upon the first gel, which can be qualitatively reproduced through Brownian dynamics simulations using a model based on a temperature-dependent interaction potential incorporating steric repulsion and van der Waals attraction. Through oscillatory rheology it is shown that secondary microgel deposition enhances the structural integrity of the previously formed single species gel, and the final structure exhibits higher elastic and loss moduli than its compositionally identical homogelled counterpart. Furthermore, we demonstrate that aging processes in the scaffold before secondary microgel deposition govern the final structural properties of the bigel, which allows a detailed control over these properties. Our results thus demonstrate how the temperature profile can be used to finely control the structural and mechanical properties of these highly tunable materials. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
ACS Nano
publisher
The American Chemical Society
external identifiers
  • scopus:85062328382
ISSN
1936-0851
DOI
10.1021/acsnano.8b09139
language
English
LU publication?
yes
id
f227c4dd-fbff-48a6-b0fc-5dc8bffbc3c4
date added to LUP
2019-03-01 12:25:57
date last changed
2019-03-17 05:13:14
@article{f227c4dd-fbff-48a6-b0fc-5dc8bffbc3c4,
  abstract     = {We investigate the collective behavior of suspended thermoresponsive microgels that expel solvent and subsequently decrease in size upon heating. Using a binary mixture of differently thermoresponsive microgels, we demonstrate how distinctly different gel structures form, depending on the heating profile used. Confocal laser scanning microscopy (CLSM) imaging shows that slow heating ramps yield a core–shell network through sequential gelation, while fast heating ramps yield a random binary network through homogelation. Here, secondary particles are shown to aggregate in a monolayer fashion upon the first gel, which can be qualitatively reproduced through Brownian dynamics simulations using a model based on a temperature-dependent interaction potential incorporating steric repulsion and van der Waals attraction. Through oscillatory rheology it is shown that secondary microgel deposition enhances the structural integrity of the previously formed single species gel, and the final structure exhibits higher elastic and loss moduli than its compositionally identical homogelled counterpart. Furthermore, we demonstrate that aging processes in the scaffold before secondary microgel deposition govern the final structural properties of the bigel, which allows a detailed control over these properties. Our results thus demonstrate how the temperature profile can be used to finely control the structural and mechanical properties of these highly tunable materials.},
  author       = {Immink, Jasper and Maris, Erik and Crassous, Jérôme and Stenhammar, Joakim and Schurtenberger, Peter},
  issn         = {1936-0851},
  language     = {eng},
  publisher    = {The American Chemical Society},
  series       = {ACS Nano},
  title        = {Reversible Formation of Thermoresponsive Binary Particle Gels with Tunable Structural and Mechanical Properties},
  url          = {http://dx.doi.org/10.1021/acsnano.8b09139},
  year         = {2019},
}