CHAMPAIGN, Ill. -- The development of activated, phenol-coated glass fibers represents a potential breakthrough in the adsorption of environmental contaminants, a team of University of Illinois researchers reports. Woven into abrasion-resistant fabrics, the fibers offer an efficient and convenient alternative to the activated carbon granules commonly in use.
The new fibers were described by James Economy, a U. of I. professor of materials science, at the September meeting of the International Union of Pure and Applied Chemistry in Seoul, South Korea.
"Our ability to tailor the pore size and pore-surface chemistry of the fibers provides us with a unique capability to design highly selective systems for enhanced adsorption of specific contaminants," Economy said. "By combining the fundamental knowledge of pore structure with the advantages of a glass fiber substrate, we can produce an effective and low-cost system for a variety of environmental applications."
The technology behind the new glass fibers was developed by Economy and U. of I. graduate students Chris Mangun and Michael Daley. The researchers have applied for a patent. "The process begins with inexpensive glass fibers, which can be woven into a variety of shapes," Mangun explained. "These glass fabrics are dipped in a phenolic resin and then 'activated' through a chemical reaction that etches small pores into the carbon. The nature of the reaction controls the pore structure and pore-surface chemistry, which control the adsorption properties of the coated assemblies."
In the early 1970s, Economy demonstrated the preparation and adsorption properties of phenol-based activated carbon fibers. Although the fibers showed significantly improved adsorption capacities over activated carbon granules, the high cost of the fibers (nearly $100 per pound) made them unattractive except for a few specialty applications.
"The cost of the new glass fiber assemblies may be as low as 80 cents per pound, which is competitive with activated carbon granules and more than 100 times less expensive than activated carbon fibers," Mangun said. The activated glass fibers offer other advantages over activated carbon granules, including excellent contact efficiency, self-containment, and ease of reactivation. Because the fibers' adsorption is reversible upon heating, easy disposal or recycling of the adsorbed material is possible.
"We have discussed our new material with adsorbent manufacturers and many users," Mangun said. "They are excited about this technology and have been working with us to provide cost-effective solutions to their problems."