Carnegie Mellon University
June 15, 2015

Concrete Science


Newell Washburn and colleagues are using polymer chemistry techniques to transform one of nature's most abundant macromolecules into a material that could improve widely available commercial products, like concrete.

Lignin is a polymer that gives structure to trees and other plants; when purified it turns into a nanoparticle with unique properties. In his lab, Washburn uses a controlled radical polymerization method to graft water-soluble polymers onto lignin, further enhancing its structural and functional properties. The resulting product is like a "lignopolymer" that can be used to bolster other materials.

"Our lab focuses on merging chemistry and engineering techniques to develop new structural materials, which make lignin a prime candidate for our work," said Washburn, associate professor in the departments of Chemistry and Biomedical Engineering.

After creating the "lignopolymers," Washburn and his colleagues demonstrated that it can be used as a plasticizer that keeps concrete from aggregating, which improves workability and reduces water requirements for the common building material. The plant-based polymer works just as well as currently used plasticizers, with the added advantage that it can be used at much lower concentrations.

Chetali Gupta, a doctoral student in Materials Science and Engineering and a member of the Washburn lab, will present this work and other studies on lignin at the 89th American Chemical Society Colloid and Surface Science Symposium that is being held on Carnegie Mellon's Pittsburgh campus from June 15–17. This is the third time that the university has hosted the conference, which brings together close to 600 scientists from 22 countries to present the latest nanotechnology research.

The symposium is organized and co-chaired by Stephen Garoff, professor and head of the Department of Physics, Jim Schneider, professor of Chemical Engineering and Bob Tilton, professor of Biomedical Engineering and Chemical Engineering.

"Nanoscience brings together a number of different fields. Newell's research is a shining example of this, combining chemistry and engineering; nature and industry," Garoff said. "This interdisciplinary meeting is a perfect fit for Carnegie Mellon, where there are no borders to how we do our work."