Complex fluids, or soft matter systems, encompass suspensions of particulates, polymeric solutions and melts, emulsions, and more. Such materials are used in a wide range of industries and products, and are also of importance to many applications in biotechnology, nanotechnology, and materials science. In most cases, the ability to predict the dynamics of these material are extremely limited, which hinders the rational design of new and efficient processes. We aim to impact the basic science and applications of complex fluids by generating new insights and improved models of their dynamics by integrating the outcomes of experiments, theory, and simulations. Much of our work examines the rheology and dynamics of particles suspended in viscous fluids using computational and experimental approaches. Additional research and development efforts include polymer dynamics and microfluidic flows.

MY RESEARCH GROUP GENERATES INSIGHTS AND SOLUTIONS to problems regarding the transport of complex fluids using experimental, computational, and theoretical methods. Complex fluids, which encompass suspensions of particulates, emulsions, polymer solutions, and more, serve important roles in a wide range of industries as well as emerging technologies. Efficient control and processing of these fluids requires predictive capabilities that, in most cases, are lacking, as they often demonstrate nonlinear dynamics that create unexpected and intriguing observations.

Some specific examples from our work are described:

MACROMOLECULAR TRANSPORT IN MICROFLUIDICS
Microfluidic, or lab-on-chip, technologies have the potential to significantly improve medical diagnostic capabilities and accelerate advances in biological and biochemical research. Realizing this promise requires the ability to model and manipulate macromolecular motion within these small devices. As one effort, we have been examining transport dynamics of DNA, a polyelectrolyte, through electrodeless channels. The work has demonstrated new and unexpected methods that can be harnessed to control the cross-stream distribution of DNA using a combination of pressure gradients and electric fields. We are validating our model of this phenomenon through rigorous comparison of experimental results and simulations while simultaneously investigating technological applications such as the extraction of DNA from biological samples.

SUSPENSION RHEOLOGY AND DYNAMICS
Suspensions of particles in viscous fluids are found in everyday materials such as concrete, in industrial advanced technological applications, and even in natural processes. Consequently, advances in evaluation in the transport properties and predictive capabilities for the dynamics will have a widely distributed impact through improved ability to rationally design processes. Some recent work in our group is focused on assessing the precise origin of irreversibilities in non-colloidal suspensions of spheres; these irreversibilities can cause, as one example, suspensions to demix during rheological testing and create inaccurate estimates of viscosities. Much of our work examines suspensions of rod-like particles, where coupling of the orientational dynamics with the flow field and center-of-mass motion creates truly complex results.

Education

Postdoctoral Associate, Chemical Engineering, Stanford University 1998-2000
Ph.D., 1998, Chemical Engineering, The University of Texas at Austin
B.S., 1993, Chemical Engineering, University of Oklahoma

Awards & Distinctions

• University of Florida Term Professor, 2017-2020
• Exceptional Service Award, UF Department of Chemical Engineering, 2013
• UF Chemical Engineering Teacher of the Year, 2011-2012
• International Educator of the Year Award, UF College of Engineering, 2011
• National Science Foundation CAREER Award, 2003
• Chateaubriand Post-doctoral Fellow, 2000-2001

selected Publications

• Microstructural dynamics and rheology of suspensions of rigid fibers; Jason E. Butler and Braden Snook; Annual Review of Fluid Mechanics 40, 299-318, 2018.
• Rheology of concentrated suspensions of non-colloidal rigid fibres; Franco Tapia, Saif Shaikh, Jason E. Butler, Olivier Pouliquen, and Elisabeth Guazzelli; Journal of Fluid Mechanics 827, R5, 2017.
• Electro-hydrodynamic concentration of genomic length DNA; Mert Arca, Anthony J.C. Ladd, and Jason E. Butler, Soft Matter 12, 6975-6984, 2016.
• Inverse Saffman-Taylor experiments with particles leads to capillarity driven fingering instabilities; Ilyesse Bihi, Michael Baudoin, Jason E. Butler, Christine Faille, and Farzam Zoueshtiagh; Physical Review Letters 117, 034501, 2016.
• Origin of critical strain amplitude in periodically sheared suspensions; Phong Pham, Bloen Metzger, and Jason E. Butler, Physical Review Fluids 1, 022201(R), 2016.