Daniel Blair

Daniel Blair

Associate Professor

428 Regents Hall
Telephone: (202) 687-5985
E-mail: dlb76@georgetown.edu

Website: http://blairlab.georgetown.edu
              http://softmatter.georgetown.edu

 

1997 - BA Physics, Elon University
2000 - SM Physics, University of Chicago
2004 - PhD Physics, Clark University

Professor Blair's work can be described as soft condensed matter physics. Soft matter or soft materials physics is a young subfield of condensed matter physics that has it's roots in polymer science. Specifically, his group is working to understand the link between the microstructure of disordered materials and their bulk mechanical properties. To accomplish this, his group is performing experiments in which they deform and measure stress propagation in soft disordered solids such as colloidal glasses, gels, and foams. The glasses we construct are surprisingly similar to their atomic counterparts, but have length and size scales that allow for direct real time information to be acquired using advanced microscopy techniques.

Professor Daniel Blair received his PhD in Physics from Clark University after obtaining a SM from the University of Chicago. Prior to his graduate work professor Blair spent over a year as a research student at Argonne National Laboratory in the Material Science Division. After receiving his PhD in 2004, he was a postdoctoral fellow in the School of Engineering and Applied Sciences and the Department of Physics at Harvard University with David Weitz. Professor Blair received a National Science Foundation Faculty Early Career Development (CAREER) award in 2009.

Professor Blair spent his sabbatical (2015-2016) at the National Institutes of Health (NIH) and the National Institute of Standards and Technology (NIST). At NIH, Prof. Blair spent his time at within the National Heart Lung Blood Institute (NHLBI) in the group of Dr. Clare Waterman investigating the influence of topology (2D vs 3D) and stiffness gradients on cellular mophodynamics.  At NIST, Prof. Blair split his time between the Materials Science and Engineering division within the Materials Measurement Laboratory (MML) and at the Center for Neutron Research (NCNR) providing expertise in the development of a micro-RHEO-SANS instrument. 

 

Current Research

Soft Glassy Solids

The Blairlab is interested understanding the structural behavior of disordered solids. Glassy materials are found nearly everywhere in nature and industry. Many soft materials, such as colloidal dispersions, exhibit behavior indicative of the glass transition. In fact, colloidal glasses exhibit many of the hallmarks associated with glasses, such as aging and heterogeneous dynamics.

In the Blairlab we utilize tools such as confocal microscopy and rheology (bulk and micro) to investigate the micromechanical structure and properties of soft glassy solids. Specifically, we investigate the spatial distribution of forces inside colloidal emulsions under shear stress. By compressing the emulsion drops, we can pick out the contact forces directly and measure how the spatial structure of those forces is changed under the application of shear. This work will provide unprecedented information into the way structurally disordered solids undergo mechanical failure.

We are also using thermally sensitive hydrogel particles to understand the onset of glassy behavior in colloidal glasses. Our contention is that the mechanical properties of the glass must be determined through the interplay between the microstructure and the particle level dynamics as the transition is crossed. To investigate these ideas, we utilize three dimensional confocal microscopy linked with bulk rheology to investigate the glassy dynamics and heterogeneous particle restructuring events under external shear. This system will allow us to definitively quantify how the inherent glassy structure affects the rheological properties of amorphous solids.

Biopolymer Networks

Professor Blair is currently using these methods to investigate how biologically derived polymeric systems . The goal of this work is to build up our knowledge of how networks of branched and cross-linked biopolymers distribute globally and locally applied strains. This will assist in understanding the varied morphologies found in cells and tissues that interact with the extracellular matrix.

Current Teaching

Fall 2016: PHYS-509 (Grad. E&M)

Selected Publications

 

  1. "Rheological signature of frictional interactions in shear thickening suspensions"
    John R. Royer, Daniel L. Blair, and Steven D. Hudson, Phys. Rev. Letters, 116, 187801 (2016).

  2. "Rheology and dynamics of colloidal superballs"
    John R. Royer, George L. Burton, Daniel L. Blair, and Steven D. Hudson Soft Matter, 11, 5656-5665 (2015). 

  3. "Rheology of Reconstituted Silk Fibroin Protein Gels: The Epitome of Extreme Mechanics"
    A. Pasha Tabatabai, David L. Kaplan, Daniel L. Blair, Soft Matter, 11, 756-761 (2015). 

  4. "Developement of a confocal rheometer for soft and biological materials" S.K. Dutta, A. Mbi, Richard C. Arevalo, and Daniel L. Blair, Review of Scientific Instruments, 84, 063702 (2013). 

  5. "Cyclic hardening in bundled actin networks", K.M. Schmoller, P. Fernandez , R.C. Arevalo, D.L. Blair, and A.R. Bausch, Nature Communications, 1, 134 (2010).

  6. Size dependent rheology of type-I collagen networks, Richard C. Arevalo, Jeffey S. Urbach and Daniel L. Blair, Biophysical Journal, 99, L65-L67, (2010).

Other Information

Professor Blair's research is funded by the Department of Commerce (NIST), National Science Foundation, The Templeton Foundation, the Petroleum Research Fund and the Air Force Office of Scientific Research (AFOSR).