Architected Lattice:  Development and Commercialization of a New Material System

Gaurav Arya, Ph.D.
Associate Professor
Department of NanoEngineering
University of California, San Diego
La Jolla, CA 92093

The incorporation of nanoparticles (NPs) into polymers constitutes a powerful strategy for enhancing their thermomechanical properties and for introducing new optical, electrical, and magnetic functionalities into the polymers. This talk reviews our recent efforts in modeling the microstructure,  assembly  mechanism,  and  viscoelastic  properties  of  such  polymer nanocomposites.  I  will  begin  by  discussing  Monte  Carlo  simulations  of polymer-grafted nanocubes that reveal the role played by the chemistry and length of the polymer grafts in           dictating the relative orientation of nanocubes within their aggregates. These results led to the development  of  a  powerful  strategy  for  fabricating  of  plasmonic  nanojunctions  from  the self-assembly of Silver nanocubes within a polymer thin film. Next, I will describe an approach for inferring dynamic parameters of NP assembly from spatially and temporally disjointed images of composites. The approach involves adjustment of the parameters of a kinetic model of assembly until the size statistics of NP clusters computed from the model match those obtained from high-throughput  analysis  of  the  experimental  images.  Application  to  shaped,  metal  NPs  in polymer films reveals that NP structures grow via a cluster-cluster aggregation mechanism, where NPs and their clusters diffuse in a Stokes-Einstein manner and stick with a probability that depends strongly on the size and shape of the NPs and the molecular weight of the polymer. Finally, I will discuss the viscoelastic behavior of polymer nanocomposites as computed from molecular dynamics simulations. Our simulations reveal intriguing parametric trends in the storage  and  loss  modulus  caused  by  interplay  between  shear  distortion  effects  and  chain relaxation dynamics. A simple analytical model based on Rouse theory is presented that captures reasonably well the observed viscoelasticity of the nanocomposites.

Gaurav Arya obtained his B.Tech. degree in Chemical Engineering from IIT Bombay in 1998, and Ph.D. degree, also in Chemical Engineering, from the University of Notre Dame in 2003. He did his postdoctoral research at Princeton University and held an Assistant Research Scientist position at New York University. He joined the Department of NanoEngineering at UC San Diego as an Assistant Professor in 2007 and was promoted to Associate Professor in 2013. Professor Arya’s research focuses on the development and application of computational methods to gain a molecular-level understanding of various biological systems and materials of interest, which include 3D genome organization in eukaryotes, DNA packaging in viruses,
DNA-based nanomachines, and nanoparticle-polymer composites. He has published 50 peer-reviewed  papers, several of which have been published in prestigious journals like Nature Nanotechnology, Nature Communications, PNAS, Annual Review of Biophysics, Nucleic Acids Research, Physical Review Letters, and Advanced Functional Materials