476310 Engineering Soft Functional Materials: From Self-Assembly to Field-Assisted Assembly

Sunday, November 13, 2016
Continental 4 & 5 (Hilton San Francisco Union Square)
Sepideh Razavi, Chemical Engineering, University of Michigan, Ann Arbor, MI

Research Interests:

Engineering Soft Functional Materials: From Self-assembly to Field-assisted Assembly

The ubiquity of self-assembly - the process of creating organizational order in systems of components - in nature has inspired technological developments towards synthetic building blocks that assemble into desirable structures with a unique set of properties. Isotropic spherical colloids are a simple example of such building blocks where their spatial arrangement yields photonic crystals that exhibit structural color. The key step towards engineering the assembly process is the ability to tune the interparticle interactions. However, the experimental realization of target structures can be challenging owing to the slow kinetics of the self-assembly process. There is a concerted effort in the field to identify the factors that impact the particle-particle interactions and control the assembly dynamics via external fields. What happens when shape or surface anisotropic particles are used as building blocks for assembly? How is the assembly in bulk different from the 2D assembly in the presence of a fluid interface? What interactions are induced in the presence of an external electric field? To address some of these questions, my research focuses on the assembly of shape and surface anisotropic colloidal particles. I present experiments on the application of fluid interfaces as a template for assembly and discuss the role of particle surface properties in tuning the mechanical stability and flow behavior of the assembled monolayer. External direct current fields are used to control the dynamics of assembly in dense colloidal suspensions and measurements of the electrophoretic mobility demonstrate the significance of the dispersion electrokinetic properties and suspension volume fraction. Given the need for generating shape-memory colloidal structures suitable for applications where rapid, on demand reconfiguration is required, I also present experiments on the actuation of dense suspension of surface anisotropic colloidal fibres using an external electric field. Insights obtained from all these studies contribute to our fundamental understanding of the principles central to the assembly processes and serve as a platform for engineering the bottom-up assembly of functional materials. Using this knowledge, I plan to find new avenues for engineering the assembly of soft functional materials.

Teaching Interests:

Teaching is a great opportunity to contribute to the formal education of the students. I have been fortunate to have the experience of both teaching in a classroom and mentoring students in the lab.  I have been a teaching assistant in a number of undergraduate courses including the transport phenomena and nanotechnology. As a part of my classroom teaching responsibilities, I have designed homework assignments, compiled some sources for various topics on the course and given lectures on the molecular dynamics simulations and their importance in the chemical engineering and materials science research. I believe that not only it is crucial to educate the future engineers on the importance of the traditional chemical engineering subjects, but is also essential to integrate computational tools as a part of the course material in order to introduce these techniques early on and discuss their relevance in advancing the field.  In addition to the classroom experience, I have mentored both graduate and undergraduate students in the lab.  Besides training the students on various research tools, I have always been passionate about encouraging critical thinking, developing the students written and oral presentation skills, and training the students to be independent researchers.

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