One of the reasons why I love science is that it gives any person the ability and the framework with which to explore and understand completely new frontiers. With chemistry, I get to play around with the materials and molecules that change our lives in both mundane and profound ways. Through my research projects, I take lessons from the ways that nature uses different types of chemicals to tackle modern challenges. Similarly, I try to look at established technologies with fresh eyes to come up with modifications that can lead to new applications. Finally, I try to share my excitement through enabling people to be involved in chemical research, whether they be my American University students or people who might have a passing interest in science.
3D printing, or additive manufacturing, is a technology that allows you to dream up new shapes and then create them in real life. As an observer, I was amazed at the objects that people were printing: prosthetic limbs, laboratory equipment, engine parts, and more. As a chemist, though, the fact that all of these objects were inert (not chemically reactive) made me sad to be missing out on all of the fun. So, my colleagues decided to do something about it. We set out to 3D print objects, using the standard commercial 3D printers, that were capable of performing specific chemical reactions. Our basic strategy is to incorporate reactive nanoparticles into common 3D printing plastics, using the same technologies that industry uses to add color to 3D printing plastics. In our first attempt at this, we incorporated TiO2 nanoparticles into acrylonitrile butadiene styrene, or ABS (which is a typical 3D printing plastic that also happens to be what Legos are made from). We found that the TiO2 kept its reactivity when incorporated into ABS and printed into an object. We have since moved on to incorporate MOFs (metal-organic frameworks) and are trying to print structures that can controllably store gases like hydrogen. We are currently playing around with changing the polymers, the nanoparticles, and the shapes that get printed all with an eye on developing technologies we think our system can play a role in.
One of the great goals of modern chemistry is to generate materials with strictly defined microscopic structure. Nature provides a number of examples that prove this aim is achievable, even thought we are not quite able to match these standards in the laboratory. Some of the most striking instances of this occur through the process of biomineralization. We are most familiar with bone and teeth. But snail and mollusk shells are other examples of this. My research attempts to highjack the generic processes of biomineralization (protein-directed nanoparticle formation, nanoparticle-directed changes in protein structure, and organization of proteins and nanoparticles into organized materials) to generate new classes of materials that nature hasn’t thought up. We are exploring uses (water purification, drug delivery, tissue culture, etc) for the novel materials coming out of our lab that are made from protein-based materials containing gold or metal oxide nanoparticles.
I am a guest researcher at the National Institute of Standards and Technologies (NIST) in Maryland. The team with whom I work, led by Zeeshan Ahmed, is interested in developing new environmental sensors and generating new standards for the American home and workplace. Together, we are blending my materials research with their sensor design know-how. Not only are we trying to find new ways to measure harmful conditions (in the atmosphere and in tissues). We are also working to design networks of connected and integrated sensors to probe complex systems like tumor tissues.
Nature has evolved enzymes (protein catalysts that facilitate very specific chemical reactions) so that they are both efficient and precise. Contrast these with most chemical catalysts used by industry, which often produce a wide arrange of byproducts that require time and energy to remove from the desired reaction target. I have a research project that explores how to facilitate the use of enzymes in industrial conditions, which are not found or used in nature. This project is part of my larger effort to use nature for unnatural chemistry.
Communicating and Engaging with Chemistry
Chemistry is a pursuit that can be captivating (hooray for fireworks and color changes) yet seem remote and hopelessly distant to the untrained. My scholarship and outreach looks to bridge this divide by engaging non-scientists with the chemistry they do in their every day lives (specifically in the kitchen) and by developing new chemical research experiences aimed at students who are training to become chemists as well as students going on to other professions. As part of this work, I take a critical look at the way chemistry has been portrayed, historically, and seek to improve upon these efforts by taking lessons from research in social sciences and communication theory. The end goal is to generate feelings of engagement in the non-professional scientist public through entertaining and engaging chemical research.