Paper Number
PO85 

Session
Poster Session

Title
Investigating the non-linear behaviour of semi-dilute PAAm aqueous solutions with a microfluidic, three-dimensional "cross-slot" flow geometry

Presentation Date and Time
October 14, 2015 (Wednesday) 6:05

Track / Room
Poster Session / Atrium/Harborview

Authors (Click on name to view author profile)

1. Lanzaro, Alfredo (the University of Manchester, School of Chemical Engineering and Analytical Science)
2. Yuan, Xue-Feng (Interdisciplinary Institute of High-Performance Computing, The National Supercomputer Centre)

Author and Affiliation Lines (in printed abstract book)
Alfredo Lanzaro¹ and Xue-Feng Yuan^2
1School of Chemical Engineering and Analytical Science, the University of Manchester, Manchester, Greater Manchester M1 7DN, United Kingdom; ²The National Supercomputer Centre, Interdisciplinary Institute of High-Performance Computing, Guangzhou, China

Speaker / Presenter 
Lanzaro, Alfredo

Text of Abstract
We investigate the flow of polyacrylamide (PAAm) aqueous solutions in a microfluidic, highly three-dimensional “cross-slot” flow geometry using our Rheo-chip platform [1,2,3,4]. The effects of varying the Weissemberg ( 1<Wi<100) as well as the Elasticity (1.8<El<58.4) numbers on the non-linear behavior of the model polymer solutions are quantitatively studied by means of micro-PIV and pressure drop measurements. The non-linear extensional viscosities are characterized up to deformation rates as high as 10⁵ s^-1. Moreover, the velocity measurements are quantitatively analyzed using our numerical method [2,3] to define a “local Deborah number” field, which creates an instant snapshot of the local stretch underwent by polymer chains in complex flow conditions. We demonstrate that our technique provides a fast and reliable measurement of the extensional properties of the model fluids over a range of deformation rates unachievable by most commercial rheometers, and using far less fluid compared to other systems previously discussed in the literature. It is envisaged that our Rheo-chip technology will bring a step change to quantitative rheological characterization of complex fluids of industrial interest (e.g. biopharmaceuticals, inks, shampoos, toothpastes) allowing for fast and high-throughput formulation screening.

[1] A. Lanzaro and X.-F. Yuan, J Non-Newtonian Fluid Mech, 2011; 166:1064;1075. [2] A. Lanzaro and X.-F. Yuan, J Non-Newtonian Fluid Mech. 2013. [3] A. Lanzaro, Z. Li and X.-F. Yuan, Microfluidics and Nanofluidics, 2015; 18:819-828. [4] X.-F. Yuan, US Patent App. 13/813,933, 2011.