Ahead of the Curve: How Bending Can be Exploited to Control Morphology and Assembly of 2D Crystals in a 2D Fluid

ABSTRACT

Ultrathin materials hold great potential to facilitate advanced flexible electronics, opto-electric materials, and materials that interface between machines and living organisms. Ultrathin sheets such as graphene bend cylindrically, but cannot assume complex contours without damage. We are interested in composite sheets containing solid and fluid domains because they possess unique capabilities. An ultrathin fluid can undergo shear and elastic stretching and therefore can assume complex shapes, while it also pays a cost to bend. Embedding small plate-like particles in such a fluid sheet produces a composite that is able to assume an array of complex contours and shapes. Moreover when those plate-like particles are Brownian, the result is a 2D colloidal suspension! Phase separated giant unilamellar phospholipid vesicles are an easily accessible example of such a composite fluid sheet: only 4 nm thick and tens of microns in diameter, in GUVs curvature would seem to be negligible. This talk explores how the contrary is true and how there is great impact on material behaviors such as crystallization and assembly of small colloidal plates into regular grids and networks.

BIOGRAPHY

Professor Maria Santore, of the Polymer Science and Engineering Department at UMass Amherst, conducts research on colloidal phenomena, nanomaterials, polymer and phospholipid membranes, and polymer interfaces. Her work is distinguished by its emphasis on reversible interactions and adhesion, that she engineers at the molecular and nanometer scales to impart dynamic function to materials. She has become newly fascinated with the role of elasticity in colloidal interactions. Santore trained as a Chemical Engineer with a concentration in Colloids and Polymers, first for her BS Degree at Carnegie Mellon and then for her Ph.D. at Princeton. Following an NRC-sponsored Post-doctoral Associateship in the Polymers Department at NIST (the National Institute of Standards and Technology), she joined the Chemical Engineering faculty at Lehigh and later moved to the University of Massachusetts at Amherst. Among Santore’s recognitions are Fellowship in the American Chemical Society, American Physical Society, American Association for the Advancement of Science and the Chancellor’s Medal and the University of Massachusetts.