Optimized Cross-Slot Flow Geometry for Microfluidic Extensional Rheometry

• Type: Article in International Scientific Journal
• Date: 2012

Authors

Simon J. Haward (Author) Other; Mónica S. N. Oliveira (Author) FEUP; Manuel A. Alves (Author) FEUP; Gareth H. McKinley (Author) Other

Journal

Title: Physical Review Letters

Vol. 109 No. 12

ISSN: 0031-9007

Publisher: American Physical Society

Indexing

ISI Web of Knowledge - 62 Citations

ISI Web of Science

Scopus - 86 Citations

INSPEC

Scientific classification

FOS: Natural sciences > Physical sciences

Associated Projects

EXTENSION - EXTENSION – Escoamento extensional de fluidos complexos em microcanais

RheoChip - Design de um "reómetro-num-chip" para o desenvolvimento de fluidos análogos ao sangue

Other information

Authenticus ID: P-002-5EV

DOI: 10.1103/physrevlett.109.128301

Abstract (EN): A precision-machined cross-slot flow geometry with a shape that has been optimized by numerical simulation of the fluid kinematics is fabricated and used to measure the extensional viscosity of a dilute polymer solution. Full-field birefringence microscopy is used to monitor the evolution and growth of macromolecular anisotropy along the stagnation point streamline, and we observe the formation of a strong and uniform birefringent strand when the dimensionless flow strength exceeds a critical Weissenberg number Wi(crit) approximate to 0.5. Birefringence and bulk pressure drop measurements provide self-consistent estimates of the planar extensional viscosity of the fluid over a wide range of deformation rates (26 s(-1) <= (epsilon) over dot <= 435 s(-1)) and are also in close agreement with numerical simulations performed by using a finitely extensible nonlinear elastic dumbbell model.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5