Crystallographic Defects in Soft Matter

Edwin L. Thomas, PhD
Texas A & M University

Abstract: Defects are symmetry breaking features within a crystal. They can be created during growth as well as by applied mechanical forces. We address point, line and surface defects in tubular network double gyroid and double diamond block copolymer crystals, a type of soft matter formed by self assembly. 3D slice and view scanning electron microscopic tomographic imaging allows analysis of the detailed nature of the structural details and defect symmetries
such as grain boundaries, twin boundaries, order-order phase transformations, dislocations and bridge defects. Often defects are considered detrimental to the properties and performance of a material, but if the mesoscale defects in 3D periodic block copolymers can be controlled, they can be utilized to achieve various advantageous functions and behaviors.

Bio: Professor Ned Thomas is a faculty member at Texas A& M University in the Materials Department and works on structure-property relationships of polymeric materials. He has also been a faculty member at University of Minnesota, University of Massachusetts, MIT, and Rice Univeristy. Thomas has been elected a member of the National Academy of Engineering and American Academy of Arts and Sciences. Thomas received a B.S. in mechanical engineering from the University of Massachusetts and his Ph.D. in materials science and engineering from Cornell University.