CINCINNATI -- Researchers in the Netherlands have found ways to making fractal structures in polymers that are more finely organized than nanostructures now taking the market by storm.
Fractal examples include the roots of a plant, where rootlet patterns are similar to the main root patterns. Other natural fractal examples include lightning strikes, structures of trees and the topography of coastlines. Essentially a fractal pattern is one whose fine structure mirrors its gross structure. By magnifying the fine structure one gets similar patterns in the overall structure.
Han Meijer described fractal structures in an Antec 2013 plenary session. The talk was the first public report of the phenomenon. Meijer, a professor of materials technology at Technical University of Eindhoven in the Netherlands, and Peter Neerincx of Sabic Innovative Plastics reported their results in the journal Macromolecular Chemistry and Physics, Vol. 214 in early 2013.
Meijer predicted the fractal technology could lead to advances in photovoltaic electric generating systems, membranes for fuel cells or gas separation, soft-touch polymers, unique thermal properties and high-resolution touch screens.
The researchers’ work showed special injection molds can create fractal, or treelike, structures with 65,000 or more “leaves” that drastically change polymer properties. Their work included examining epoxies, polystyrene, polycarbonate and polypropylene. Special static mixers co-injected the polymers through injection molds to align in fractal patterns.
“It’s pretty impressive,” said Akron University’s Department of Polymer Engineering professor Mike Cakmak in a telephone interview. “It’s a way of ground-breaking processes.”
Cakmak said it remains to be seen how well the fractal technology could be applied commercially. One issue is how to preserve the fractal structure in a manufacturing environment.
“But it’s worth broadcasting,” Cacmak stated.
In an email, Meijer said fractal technology gives ordered structures to polymer mixtures, unlike interpenetrating and other systems where mixing is unordered.
“Basically we do prefer to work on controlled organization rather than uncontrolled self-organization,” he said. “The research is unique and in its infancy,” Meijer said, adding that the work is not tied yet to a commercial partner.
Cakmak concurred the research in unique.
Cakmak leads other research that could be a game-changer in polymer films. His group is working on specialty films with particles electromagnetically aligned perpendicular to the film’s surface. The process can make high-value-added films using mono¬mers for polyimides, polysulfones and other polar components.