The American University team worked with researchers from the National Institute of Standards and Technology (NIST) and the Food and Drug Administration (FDA), in order to demonstrate that “titanium oxide nanoparticles blended into a 3D printed polymer not only enhance the mechanical properties of the structure but also the chemical properties.” The chemistry of nanoparticles that are embedded in a polymer composite that’s 3D printed only works because polymers are permeable, which allows access between the nanoparticles and other chemicals in the environment. However, their work could benefit from further experimentation: Hartings mentions that the “polymer used in the reported results is not optimally suited” for the chemistry his team is attempting to support. The team used acrylonitrile butadiene styrene, as they “noticed more decomposition in the polyactic acid during extrusion.” But they note that other polymers could be better in the future.Hartings said, “People (secretly, sometimes) love having control. They love to be able to design and create and build. 3D printing facilitates this kind of creative control. With the technologies that we are developing, we are adding a 4th dimension to 3D printing: chemistry.”
“I’m really interested in the way that our 3D printed nanocomposites can store and filter gases. Developing new ways to trap gases like carbon dioxide and hydrogen and methane will have huge implications for our environment and society,” said Hartings.
In a nutshell, researchers doused a small, plastic structure with chemically active titanium dioxide (TiO2) nanoparticles, then added them to a standard 3D printing filament and printed a small, plastic matrix. TiO2 is a semiconductor, and in the form of nanoparticles, due to its increased surface area, it features enhanced photocatalytic properties. The experiment, with a resounding ‘yes,’ answered two key questions:
- Would the nanoparticles stay active in the structure once printed?
- Created for pollution mitigation, would the matrix perform?
In chemistry experiments, the technology has historically been used only to produce structures used to help research other materials and structures, like reactionware, instead of creating structures to be studied.
Hartings said, “As a chemist, printed things are kind of boring. I wanted 3D printed objects to be able to do chemistry after they were printed.”
Until now, chemists really only thought of 3D printed structures as inert objects. But thanks to the efforts of Hartings and his now award-winning team and experiment, it looks like that could change. Discuss in the American University forum at 3DPB.com.