Presenter Information

Guram Gogia, Colby CollegeFollow

Location

Diamond 341

Start Date

1-5-2014 9:00 AM

End Date

1-5-2014 10:50 AM

Project Type

Presentation

Description

Soft matter systems are known to exhibit a range of phase behaviors when driven out of thermodynamic equilibrium. Using a confocal rheoscope, we investigated configurations of monodisperse colloidal particles under oscillatory shear. In the absence of shear, colloids, like other soft matter particles, exhibit equilibrium behavior, dominated by random Brownian motion. When colloidal suspensions get sheared, various ordered structures emerge. By modifying shear cell gap width and shear frequency and amplitude, we observed HCP crystalline structure and buckled phase, as well as unexpected density fluctuations. Namely, there were crystalline structured stripes of particles arranged perpendicular to the shear direction. This talk will review the experimental techniques and properties of above mentioned structures.

Faculty Sponsor

Duncan Tate; Liz McGrath

Sponsoring Department

Colby College. Physics and Astronomy Dept.

CLAS Field of Study

Natural Sciences

Event Website

http://www.colby.edu/clas

ID

556

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May 1st, 9:00 AM May 1st, 10:50 AM

Shear-Induced Structures in Colloidal Suspensions

Diamond 341

Soft matter systems are known to exhibit a range of phase behaviors when driven out of thermodynamic equilibrium. Using a confocal rheoscope, we investigated configurations of monodisperse colloidal particles under oscillatory shear. In the absence of shear, colloids, like other soft matter particles, exhibit equilibrium behavior, dominated by random Brownian motion. When colloidal suspensions get sheared, various ordered structures emerge. By modifying shear cell gap width and shear frequency and amplitude, we observed HCP crystalline structure and buckled phase, as well as unexpected density fluctuations. Namely, there were crystalline structured stripes of particles arranged perpendicular to the shear direction. This talk will review the experimental techniques and properties of above mentioned structures.

http://digitalcommons.colby.edu/clas/2014/program/168