Macroscopic Materials Built from Nanoparticle Superlattices


Macroscopic Materials Built from Nanoparticle Superlattices

Rob Macfarlane, MIT

3:30 p.m., September 27, 2022   |   B001 Geddes Hall

One of the promises of nanotechnology in its early developmental stages was the ability to make designer materials with precise control over individual building block composition and organization in 3D space. In recent years, material synthesis methods have advanced to be able to create a multitude of nanoparticles of varying sizes, shapes, and compositions, providing a vast array of building blocks to use as materials fabrication components.

Robert Macfarlane
Robert Macfarlane

In addition, processing methods have been developed to arrange these nanoparticles into ordered arrays, to dry them into thin films, and even to sinter them into more complex bulk materials. However, the fundamental promise of being able to build a material with controlled structure across the length scales of atomic crystal structure, nanoscale size, shape, and organization, and ultimately material microstructure and macroscopic form has been challenging to realize. A major advancement would therefore be a materials synthesis and processing route that could create free-standing, macroscopic materials or arbitrary three dimensional shapes with precisely controlled nanoparticle positions across the entirety of the material composition.

Here, we demonstrate a nanoparticle-based building block called a “Nanocomposite Tecton (NCT)” that enables a self-assembly route to fabricating free-standing solids of arbitrary macroscopic shapes that can utilize a multitude of different nanoparticle compositions and shape, and also possess specifically programmed nanoscale particle arrangements and controlled microstructure. This talk will outline the key synthesis and processing steps that enable this method of making materials with programmed material structure across ~7 orders of magnitude in length scale, thereby realizing a long-standing goal of nanomaterials fabrication.

Rob Macfarlane is the Paul M. Cook Associate Professor of Materials Science at MIT, where he has been a faculty member since 2015. Rob obtained his Ph.D. in chemistry in the lab of Chad Mirkin in 2013 at Northwestern University and was awarded a Kavli Nanoscience Institute post-doctoral fellowship at Caltech, where he worked with prof. Robert Grubbs and Harry Atwater from 2013-2015.

He is the recipient of numerous awards including an NSF CAREER award, AFOSR Young Investigator Award, the ACS Unilever Young investigator Award, and a 3M Non-tenured Faculty Award. He is an expert in the fields of self-assembly, nanocomposites, materials chemistry, and nanomaterials processing, and his research lab sits at the interface of these fields to establish new materials fabrication techniques.

His lab’s research focuses on developing systems-level approaches to materials synthesis, where structural features at the molecular, nano, and macroscopic length scales act together as integrated design handles to control a material’s hierarchical ordering. These materials range from inorganic nanoparticles to synthetic polymers to biomacromolecules like DNA, and the structures have potential utility in diverse applications ranging from energy storage to protective coatings.