Paper Number
SC34
Session
Suspensions, Colloids and Granular Systems
Title
Effects of shape on the rheology of polymer-grafted nanoparticles in solution
Presentation Date and Time
October 11, 2017 (Wednesday) 5:00
Track / Room
Track 3 / Crystal C
Authors
- Parisi, Daniele (FORTH-IESL)
- Vlassopoulos, Dimitris (FORTH-IESL)
- Loppinet, Benoit (FORTH-IESL)
- Liu, Chen-Yang (Institute of chemistry chinese academy of sciences)
- Ruan, Ying-Bo (Institute of Chemistry Chinese Academy of Science)
Author and Affiliation Lines
Daniele Parisi1, Dimitris Vlassopoulos1, Benoit Loppinet1, Chen-Yang Liu2, and Ying-Bo Ruan2
1FORTH-IESL, HERAKLION, Greece; 2Institute of Chemistry Chinese Academy of Science, Beijing, China
Speaker / Presenter
Parisi, Daniele
Text of Abstract
The large majority of rheological investigations with soft colloids involve spherical particles. However, in several applications the particles are anisotropic. Here, we focus on polymer-grafted nanoparticles in solution and compare three soft systems with different core shape (spheres, cylinders and lamellas) but identical chemistry and molar mass of the graft, and very similar grafting density. These systems have different overlap fractions and spatial organization. Concentrated solutions at the same mass concentration have been investigated by means of dynamic light scattering and rheology in both linear and nonlinear regime. We find that shape affects substantially the relaxation time, yielding mechanism and residual stresses, which reflect different particles arrangement in solution. We compare against relevant data in the literature with hard spheres, ellipsoids and other soft spheres, and attempt at extracting a generic phenomenological picture of rheology vs. shape and concentration. These results show that advantages of shape in tailoring the flow properties of dense soft colloids and provides guidelines for understanding its role in the mechanisms of viscoelasticity and yielding.