Purdue University researchers develop biodegradable films from cellulose
The production process preserves the strength and biodegradability of cellulose while rendering it transparent and flexible.
Researchers from Purdue University, West Lafayette, Ind., developed tough, flexible, biodegradable films from cellulose—the main component of plant cell walls—for food packaging.
Food scientists Srinivas Janaswamy and Qin Xu engineered the cellophane-like material by solubilizing cellulose using zinc chloride, a common inorganic salt, and adding calcium ions to cause the cellulose chains to become tiny fibers known as nanofibrils, thus greatly increasing the material's tensile strength. The zinc chloride and calcium ions work together to form a gel network, allowing the researchers to cast the material into a transparent, food-grade film.