Mechanics of Nanomaterials: The Pivotal Role of Molecular Interactions
Dinesh R. Katti, PH.D, P.E.
Interim Chair and Professor
Department of Civil and Environmental Engineering
North Dakota State University, Fargo, ND
Abstract
This talk will expound the dominant role of molecular interactions on the mechanics of nanomaterials that include biological and synthetic nanocomposites and smectite clays. The presentation will focus on four nanomaterials, 1) nacre, the inner layer of seashells, 2) bone, 3) polymer-clay-nanocomposites and 4) swelling clays. The mechanisms that control mechanical properties of the nanomaterials are elucidated using innovative multiscale modeling and experimental techniques. The important discoveries and key findings made by the Katti group that reveal the important mechanisms that lead to unique properties exhibited by these nanomaterials will be described. The modeling and experimental techniques developed for these studies bridge wide range of length scales from molecular to nano/micro to macroscale using ab-inito, molecular dynamics, discrete element and finite element for modeling; and spectroscopy, electron microscopy and nanomechanical testing for experimental investigation. These techniques have led to simulations based materials design of synthetic nanocomposite materials. In nanocomposites, the nanoscale proximity of minerals and macromolecules alter the mechanics of the macromolecules, thus strongly influencing the mechanics of nanomaterials at the macroscale. This phenomenon is observed in naturally occurring nanocomposites such as seashells and bone as well as engineered nanocomposites and is thus a characteristic of nanoscale material systems.
Bio
Prof. Dinesh Katti received his B.S. degree in civil engineering from National Institute of Technology, Srinagar, India, M.S. degree in geotechnical engineering from Indian Institute of Technology, Bombay, India and Ph.D. in civil engineering from University of Arizona, Tucson. After receiving his doctoral degree in 1991, he joined the industry as a geotechnical consulting engineer for two companies in the Seattle area, Dames and Moore and Terra Associates where he worked on over 125 projects. He joined North Dakota State University in the department of civil engineering in the fall of 1996 as an associate professor. In 2002 he was promoted to the rank of full professor. He served as chairman of the department of civil engineering at NDSU from 2004 to 2009. During the same period, he served as Associate Dean of Research for the College of Engineering and Architecture. Since fall 2013 he serves as interim chair of the department.
Prof. Katti's research expertise is in the area of multiscale modeling of materials. His research contributions are in a number of materials systems such as swelling clays, nacre, bone, polymer clay nanocomposites, bone tissue engineering and oil shales. His research is supported by NSF, USDA and DoE. He has authored or coauthored over 150 papers, 3 books and 7 book chapters. He also holds 3 provisional patents. He was awarded the 2011 John R. Booker excellence award from IACMAG for "major contributions to geomechanics". He has also received the Fred Waldron award for excellence in research in 2013. He has served as chair of the Engineering Mechanics Institute Poromechanics and Properties of Materials Committees, and currently chairs the EMI Molecular Scale Modeling and Experimentation Committee. He is also an associate editor of two EMI journals and has been instrumental in organizing symposium series on biological and biologically inspired materials for ASCE EMD/EMI for over a decade.