New Method For Developing Mechanically-reinforced Polymer Nanocomposites Developed

The incorporation of nanoparticles into polymers is a design approach that is used in all areas of materials science, says Christoph Weder of Case Western Reserve University,  senior author of the paper in Nature Nanotechnology, adding that in the past, the broad technological utilization of polymer nanocomposites has been stifled by a lack of effective methods to control nanoparticle dispersion in materials.

In their new approach, the team used a process in which the reinforcing nanoparticles are first assembled into a three-dimensional network through gelation of nanoparticle dispersion, essentially forming a template. This template can then be filled with any polymer of choice by exchanging the solvent with a polymer-containing solution.

"Through the use of this new technique, we have been able to take the most incompatible components and show that they can be used to make compatible materials," Weder said.

While the research primarily focused on cellulose "whiskers" as the choice of nanoparticles since they offer useful mechanical properties and are readily obtained from renewable biosources such as wood and cotton, Capadona explained, the team also started to investigate an array of different polymers and nanofibers, demonstrating that the technique has broad applicability.

Jeffrey R. Capadona, associate investigator at the VA's Advanced Platform Technology (APT) Center and Christoph Weder and Stuart Rowan, professors of macromolecular science and engineering at the Case School of Engineering and their colleagues.

In addition to Weder, Capadona and Rowan, other members of the research team include Dustin J. Tyler, the Nord Distinguished Assistant Professor of Biomedical Engineering at Case Western Reserve and APT associate director; Otto van den Berg and Michael Schroeter, both former postdoctoral researchers in Weder's Functional Polymer Laboratory; and Lynn A. Capadona of the polymeric materials branch, NASA Glenn Research Center. While the work was primarily conducted in the Case School of Engineering's department of macromolecular science and engineering, the Department of Veterans Affairs and the VA Rehabilitation R&D Center of Excellence in Advanced Platform Technology (APT) contributed financially and played an important role in this research uniting Weder, Capadona, Tyler and Rowan to conduct research in the area of adaptive nanocomposite materials, which are now fabricated by the new process.

This research was published in the December 2007issue of Nature Nanotechnology. Case Western Reserve University has filed for a patent protecting the technology.