Starch usually is too thick of a substance to make into fibers, but food scientists at Penn State have discovered a method that converts it into strands that could be used to make less expensive and more environmentally friendly bandages and paper products.
“There are many applications for starch fibers,” says Lingyan Kong, graduate student, food science, who worked on the research team, in a Penn State press release. “Starch is the most abundant and also the least expensive of natural polymers.”
Starch, a polymer typically found in corn, potatoes, arrowroot and other plants, and often thought of as cornstarch, is made of amylose and amylopectin. It does not easily dissolve in water, instead becoming a gel or paste that is too thick to make into fibers. But the researchers solved that problem by adding a solvent that dissolved the starch but kept its molecular structure intact.
After adding the solvent, the food scientists use an electrospinning device that helps stretch the starch solution into fibers. The device sends a high-voltage electrical charge into the mixture to create a charge repulsion to overcome surface tension, which stretches the droplets of starch into long strands.
The fibers can be made using a range of amylose concentrations from 25% to 100%. Because starch is so abundant, it is less expensive than other materials currently used to form fibers, Kong says. For example, cellulose, typically derived from trees, and petroleum-based polymers are the most common sources of polymers. However, they both continue to increase in price, as well as present environmental challenges.
“Starch is easily biodegradable, so bandages made from it would, over time, be absorbed by the body,” Kong says. “So, you wouldn’t have to remove them.”
Source: “Inexpensive, Abundant Starch Fibers Could Lead to ‘Ouchless’ Bandages,” Penn State press release, 5/1/12
Image by Frivadossi, used under its Creative Commons license.
Dale McGeehon has been a journalist and editor for more than 25 years, covering chemical regulation and testing for Pesticides and Toxic Chemical News and innovations in material sciences for the National Technology Transfer Center. His writing credits include Omni and College Park magazines and The New York Times.