Université de Fribourg

Jamming and overpacking fuzzy microgels: Deformation, interpenetration, and compression

Conley, Gaurasundar M. ; Aebischer, Philippe ; Nöjd, Sofi ; Schurtenberger, Peter ; Scheffold, Frank

In: Science Advances, 2017, vol. 3, no. 10, p. e1700969

Tuning the solubility of fuzzy polymer microgels by external triggers, such as temperature or pH, provides a unique mechanism for controlling the porosity and size of colloidal particles on the nanoscale. As a consequence, these smart microgel particles are being considered for applications ranging from viscosity modifiers and sensing to drug delivery and as models for the glass and the...

Université de Fribourg

Relationship between rheology and structure of interpenetrating, deforming and compressing microgels

Conley, Gaurasundar M. ; Zhang, Chi ; Aebischer, Philippe ; Harden, James L. ; Scheffold, Frank

In: Nature Communications, 2019, vol. 10, no. 1, p. 2436

Thermosensitive microgels are widely studied hybrid systems combining properties of polymers and colloidal particles in a unique way. Due to their complex morphology, their interactions and packing, and consequentially the viscoelasticity of suspensions made from microgels, are still not fully understood, in particular under dense packing conditions. Here we study the frequency-dependent...

Université de Fribourg

Superresolution microscopy of the volume phase transition of pNIPAM microgels

Conley, Gaurasundar M. ; Nöjd, Sofi ; Braibanti, Marco ; Schurtenberger, Peter ; Scheffold, Frank

In: Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2016, vol. 499, p. 18–23

Hierarchical polymer structures such as pNIPAM microgels have been extensively studied for their ability to undergo structural and physical transformations that can be controlled by external stimuli such as temperature, pH or solvent composition. However, a direct three-dimensional visualization of individual particles in-situ has so far been hindered by insufficient resolution, with optical...

Université de Fribourg

Light Transport and localization in two-dimensional correlated disorder

Conley, Gaurasundar M. ; Burresi, Matteo ; Pratesi, Filippo ; Vynck, Kevin ; Wiersma, Diederik S.

In: Physical Review Letters, 2014, vol. 112, no. 14, p. 143901

Structural correlations in disordered media are known to affect significantly the propagation of waves. In this Letter, we theoretically investigate the transport and localization of light in 2D photonic structures with short-range correlated disorder. The problem is tackled semianalytically using the Baus-Colot model for the structure factor of correlated media and a modified independent...

Université de Fribourg

Super resolution imaging of genetically labeled synapses in drosophila brain tissue

Spühler, Isabelle A. ; Conley, Gaurasundar M. ; Scheffold, Frank ; Sprecher, Simon G.

In: Frontiers in Cellular Neuroscience, 2016, p. 142

Understanding synaptic connectivity and plasticity within brain circuits and their relationship to learning and behavior is a fundamental quest in neuroscience. Visualizing the fine details of synapses using optical microscopy remains however a major technical challenge. Super resolution microscopy opens the possibility to reveal molecular features of synapses beyond the diffraction limit....