I-FMD Grand Rounds

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I-FMD's Material and Devices
Grand Rounds
 

Fridays at 12 pm
 

Spring 2022 Schedule

February 22, 2022 at noon, Whitaker 303

Distinguished Interdisciplinary Rounds

Spontaneous Emergence of Chirality in Achiral Systems
Mohan Srinivasarao,
School of Materials Science and Engineering, School of Chemistry and Biochemistry
Georgia Institute of Technology

*Lunch will be provided at 11:30am in the Whitaker Lobby. You must register to participate.

Abstract:
 Lyotropic chromonic liquid crystals (LCLCs) are a relatively new class of liquid crystals (LCs) that have attracted considerable attention in recent years. Applications of these materials have been explored as polarizers, optical compensators, biosensors, precursors of aligned graphene and templates for mesoporous nanofibers. LCLCs consist of many dyes, drugs, nucleic acids, antibiotics, carcinogens and anti-cancer agents.  In this talk I will explore the spontaneous emergence of chiral structures from achiral lyotropic chromonic liquid crystals when confined to cylindrical capillaries with various boundary conditions.  When confined to a cylindrical geometry with planar boundary conditions, the presumed ground state of a nematic fluid corresponds to that of an axial configuration, where the director, free of deformations, lies along the long axis of the cylinder.  However, upon confinement of lyotropic chromonic liquid crystals in cylindrical geometries, we uncover a surprising ground state corresponding to a doubly twisted director configuration. The stability of this ground state, which involves significant director deformations, can be rationalized by the saddle-splay contribution to the free energy. It will be shown that sufficient anisotropy in the elastic constants drives the transition from a deformation-free ground state to a doubly twisted structure, and results in spontaneous reflection symmetry breaking with equal propensity for either handedness. Enabled by the twist angle measurements of the spontaneous twist, we determine the saddle-splay elastic constant for chromonic liquid crystals.  I will also discuss the path to a monodomain or a single crystal, if you will, of chrominc liquid crystals confined to a rectangular capillary enabled by a spontaneous twist deformation.

Nayani, K. et al. Spontaneous emergence of chirality in achiral lyotropic chromonic liquid crystals confined to cylinders. Nat. Commun. 6:8067 doi: 10.1038/ncomms9067 (2015).

Biography:
Dr. Srinivasarao received his B.Sc. (Applied Sciences) from the University of Madurai in 1979, and M.Sc. (Applied Chemistry) from the University of Madras in 1981.  He received his M.S. (Polymer Science) in 1985 and Ph.D. in Chemistry in 1990, both from Carnegie Mellon University. He spent a few years as a postdoctoral fellow with Professor Richard S. Stein at the University of Massachusetts at Amherst before moving to AT&T Bell Labs. He spent four years as an Assistant Professor at North Carolina State University before moving to Georgia Institute of Technology in 1999.  Presently he is a full professor at Tech and is a Fellow of the American Physical Society (APS) and American Association for Advancement of Science (AAAS).


Previously recorded seminars. Log in required.

date speaker presentatoin title

June 4, 2020

Frank Zhang, Bioengineering/Mechanical Engineering and Mechanics

Viral Adhesion and Invasion: What We Learned from Ebola and COVID-19

June 11, 2020

Anand Jagota, Bioengineering/Chemical and Biomolecular Engineering

Dislocations at Soft Interfaces

June 18, 2020

Volkmar Dierolf, Physics

Rare Earth Ions in Semiconductors: From Solid State Lighting to Quantum Communications

June 25, 2020

Himanshu Jain, Materials Science

The Architectured Glass

July 9, 2020

Ivan Biaggio, Physics

A story of excitons in molecular crystals: open questions about fission, fusion, entanglement, and transport in rubrene

July 23, 2020

Peter Zeitler, Earth and Environmental Sciences

Molehills to mountains: using diffusion kinetics to measure the thermal histories of rocks

July 30, 2020

Arup SenGupta, Chemical & Biomolecular Engineering / Civil & Environmental Engineering

Harnessing the Donnan membrane Principle in Developing Smart Materials and Processes in Water Space

September 25, 2020

Helen Chan, Materials Science & Engineering

Synectics: From Reaction Bonding to Single Crystals

October 2, 2020

Ryan Thorpe, Research Scientist, Materials Characterization Facility

How to judge a book by its cover: applications of surface science in academia and industry

October 9, 2020

Daniel Ou-Yang, Physics

Optical tweezers: harnessing photons to manipulate nanoparticles and biomolecules

October 16, 2020

Jonas Baltrusaitis, Chemical & Biomolecular Engineering

Is nitrogen the new carbon? A convoluted story of production, use, and sustainability of modern fertilizers

October 23, 2020

Michael Stavola, Physics

The remarkable versatility of hydrogen as an impurity in semiconductors

November 6, 2020

Nicholas Strandwitz, Materials Science & Engineering

Atomic Masonry: Building the Nanoscopic World One Angstrom at a Time

November 13, 2020

Michael Kramp, Professor of English & Director, Lehigh Humanities Lab
Amanda Greene, Andrew W. Mellon Postdoctoral, Research Associate

Reimagining Sustainability: Why and How We Sustain What We Sustain? 

February 26, 2021

Anand Ramamurthi, Professor and Department Chair Department of Bioengineering

Platform Technologies to Grow and Repair Biological Rubber Bands

March 19, 2021

Keisha Antoine '01, '07 PhD
Educator

Water from an Outsider's Perspective

March 26, 2021

Yaling Liu, Professor, Bioengineering Mechanical Engineering & Mechanics

Toward Precision Medicine: Cell Characterization, Isolation, Culturing, and Drug Testing

April 2, 2021

Y.C. Ethan Yang, Assistant Professor, Civil & Environmental Engineering

Evaluating Complex Adaptive Water Systems with Agent-Based Modeling  

April 9, 2021

Ed Webb, Associate Professor, Mechanical Engineering & Mechanics

Blood clotting and the biopolymeric flow sensor, von Willebrand factor

April 16, 2021

Ganesh Balasubramanian, Associate Professor, Mechanical Engineering & Mechanics

Predict | Build | Test | Repeat

April 23, 2021

Elizabeth Young, Assistant Professor, Chemistry

Shedding light on photo-initiated chemical transformations using spectroscopy

May 7, 2021

James Gilchrist, Professor, Chemical & Bi0molecular Engineering

Self-organization on the run: examples of dynamically controlled colloidal assembly

September 24, 2021

Dr. Venkataraman Swaminathan, Distinguished Research Fellow, Lehigh University

A Materials Science Perspective of Quantum Materials

October 1, 2021

Elsa Reichmanis, Professor and Carl Robert Anderson Chair in Chemical Engineering Department of Chemical and Biomolecular Engineering

Conjugated Polymers: From Chemistry and Processing to Applications

October 8, 2021

Mark Chen, Assistant Professor, Chemistry

Open-Shell Molecules: A Radical Design for Organic Optoelectronic Materials

October 15, 2021

Kristen Jellison, Professor, Civil & Environmental Engineering

Biomimetic surface development for the detection, inactivation, and study of the protozoan parasite Cryptosporidium parvum

October 29, 2021

D.A. Drabold, Ohio University

Atomistic simulation of disordered materials

November 19, 2021

Israel Wachs, G. Whitney Snyder Professor, Chemical and Biomolecular Engineering Director, Operando Molecular Spectroscopy and Catalysis Research Lab

Monitoring the Surfaces of Materials in Action


For more information, please contact Nikki Rump.

*Grand Rounds is a term borrowed from the medical education community to share the latest, unique advancements across all specialties. The lectures will be at the “Scientific American” level and will be suitable for all STEM audience.

*Lectures will be recorded.