(7ci) Complex Fluids and Anisotropic Liquids for Molecular Engineering and Rational Material Design

Authors: 
Sadati, M. - Presenter, The University of Chicago
I received my PhD degree in Polymer Physics at the ETH, in Zürich, under the supervision of Prof. Hans Christian Oettinger. As a PhD student, I worked on various aspects of complex-fluid rheology, involving the interplay between mesoscale structure and dynamics. I designed and built a novel experiment, in which a lubricated cross-slot channel was employed to deform polymeric molecules in a complex flow geometry, thereby allowing me to generate some of the most precise data available for the rheology of polymer melts in a mixed shear and extensional flow. In addition, I developed a finite-element based data analysis technique to reconstruct accurate field kinematics from experimental data, with which I could examine the performance of various rheological models using numerical simulations. I worked closely with theorists, computational scientists, and other experimentalists to address what is widely viewed as a particularly challenging problem.

As a postdoctoral fellow in Prof. Fredberg’s lab at Harvard University, building on my background in polymer rheology, I developed an assay to study the dynamics of living cells under geometrical confinement, and I designed a new device to explore intercellular shear deformation. My work helped discover new mechanism for the response of the epithelial cells to large intercellular shear deformations. In my current postdoctoral position at the University of Chicago, I have worked on the coupling of structure and dynamics of structured fluids, including liquid crystals, under the supervision of Prof. Juan de Pablo. We have shown that liquid crystal-aqueous interfaces are capable of reporting the aggregation of polypeptides in its early stages, and have shown that reducing water activity by adding salts to an aqueous phase can initiate transport of dissolved water across liquid crystal membranes. These results have provided fundamental new principles for the design of biological sensors, drug delivery systems, and molecular machines. Working with scientists at the Argonne National Laboratory, we have also developed a detailed structural view of liquid crystal molecules at interfaces, using synchrotron X-ray reflectivity and Grazing-incidence small-angle scattering measurements. On a different project, I have developed a new platform for deformation of chiral liquid crystals, which has allowed me to discover new phases of these systems, and to propose exciting new applications in the area of mechano-optical metamaterials.

Selected Publications (15 published and 4 under preparation)

1- M. Sadati, H. Ramezani, W. Bu, E. Sevgen, Z. Liang, C. Erol, M. Rahimi, N. Taheri Qazvini, B. Lin, N. L. Abbott, B. Roux, M. L. Schlossman and J. J. de Pablo, “Molecular Structure of Canonical Liquid Crystal Interfaces”, Journal of the American Chemical Society (JACS), 139, 3841 (2017)

2- H. Ramezani, M. Sadati, M. Rahimi, B., Roux and J. J. de Pablo, “Understanding Atomic-Scale Behavior of Liquid Crystals at Aqueous Interfaces”, Journal of Chemical Theory and Computation, 13, 237 (2017)

3- J. Martinez-Gonzalez, X. Li, M. Sadati, Y. Zhou, R. Zhang, P. F. Nealey and J. J. dePablo, “Directed Self-assembly of Liquid Crystalline Blue-phases into Ideal Single-crystals”, Nature Communications (2017), doi:10.1038/ncomms15854

4- M. Sadati, A. Izmitli Apik, Julio C. Armas-Perez, Jose Martinez-Gonzalez, Juan P. Hernandez-Ortiz, N. L. Abbott and J. J. de Pablo,” Liquid Crystal Enabled Early Stage Detection of Beta Amyloid Formation on Lipid Monolayers”, Advanced Functional Materials, 25, 6050 (2015), (Featured on the Journal’s Cover).

5- M. Sadati, N. Taheri Qazvini, R. Krishnan, C. Y. Park and J. J. Fredberg, “Collective Migration and Cell Jamming”, Differentiation, 86, 121 (2013).

6- M. Sadati, C. Luap, M. Kröger, B. Lüthi, and H. C. Öttinger, “Application of Full Flow Field Reconstruction to a Viscoelastic Liquid in a 2D Cross-slot Channel”, Journal of Non -Newtonian Fluid Mechanics, 192, 10 (2013).

Research Interests: As a new faculty member, my future research will include exploring structure rheology-property relationships of polymeric materials and lyotropic and biological liquid crystalline mesophases, with a focus on linking molecular information to micron-scale phenomena, and on finding new routes to engineer innovative functional materials with tunable properties for drug delivery, biomedical and photonics applications. Building on my background in polymer physics, I also intend to pursue my research goals through a combination of both experimental and theoretical means and to create a rational framework with which to develop the necessary rheological and processing aspects that arise in additive manufacturing of soft materials.

Teaching Interests: I have been a teaching assistant for Polymer Physics and Finite-Elements at the Materials Department Institute at the ETH Zurich. I have also taught undergraduate students in three rheology laboratory courses. In addition, I have supervised eight undergraduates and two graduate students at Harvard University and at the University of Chicago on various research projects. With my background in Polymer Physics and Engineering, I have a strong foundation in materials science and chemical engineering, with an emphasis in polymer science related courses such as polymer physics, polymer chemistry, crystallization, rheology and polymer characterization.

Topics: