Contact: Bob Nelson For immediate release
(212) 854-6580 March 2, 1998
[email protected]
Sweet Clothes, Clean Environment
__________________
Columbia Scientists Adapt Sugar-Based Detergents for Everyday Use
Chemists and engineers at Columbia University are finding dozens of new
uses for a class of more effective, less polluting detergents, using industrial
materials based on sugar.
The materials, called surfactants, have been developed by chemists at
European and American chemical companies, but are being adapted at Columbia
for novel uses in households, medicine and industry, from getting clothes cleaner
to lubricating titanium implants. The research comes at a crucial time for
consumer products companies, which are seeking replacements for synthetic
detergents that are not easily degraded and require additives to soften hard water.
Work at Columbia is focusing on molecular analysis of the materials to
understand their novel properties, testing them for new uses and attaching
molecules of them together in new ways to create super-cleaning agents.
A key industry advance has been the creation of surface-acting
polyglucosides, short chains of two glucose molecules with attached hydrocarbon
side groups, that are extremely effective at dissolving grease and can, for
example, clean soils contaminated by gasoline. The sugar-based polymers are
milder than soaps, can be used in personal care products, are easily digested by
microbes, are tolerant of hard water and leave no trace in the environment.
"There is no reason to restrict these new materials to industrial use," said
Ponisseril Somasundaran, LaVon D. Krumb Professor of Mineral Engineering in
the Henry Krumb School of Mines at Columbia. "We believe they have better
cleansing properties than today's household products, and are equal or better in
biodegradability."
The National Science Foundation notified Columbia in late February that it
would fund the University's $500,000 proposal over five years for its
Industry/University Center for Surfactants, to be based in the Fu Foundation
School of Engineering and Applied Science. To complete the $2.3 million, five-
year budget for the center, Columbia will also receive a total of $350,000 annually
from 15 corporate partners it has so far recruited, including Akzo Nobel Corp.,
ARCO Exploration & Production Technology, CIBA Specialty Chemicals, Colgate-
Palmolive Co., Halliburton Energy Services, Henkel Corp., International
Specialty Products, LeaRonal Inc., Rhone Poulenc Inc., Rohm & Haas Co. and
Unilever Research U.S.
In addition to Professor Somasundaran, who is also director of the
Langmuir Center for Colloids and Interfaces at Columbia and principal
investigator of the NSF grant, researchers affiliated with the center are Paul
Duby, professor of mineral engineering; Carl Gryte, professor of chemical
engineering and applied chemistry; Brian Pethica, adjunct senior research
scientist; Nicholas Turro, William P. Schweitzer Professor of Chemistry; and
Alan West, associate professor of chemical engineering and applied chemistry.
Surfactants - surface-active compounds such as soaps and detergents -
have at least one hydrophobic and one hydrophilic region; the former binds to
insoluble grease or dirt, while the latter provides a region that can interact with
water. Surfactants coat the surface of grease or dirt particles, breaking them up
to be flushed away, or can bind to artificial polymers and hold them in suspension
for use as paints, advanced lubricants and anticorrosive coatings. Other uses are
in pharmaceuticals, cosmetics, food processing, advanced ceramics, micro-
electronics, liquid crystals, fuels, photographic films and biotechnology.
Researchers at Columbia are trying to understand the properties of the new
surfactants by conducting molecular-level studies using advanced chemical
techniques such as fluorescence spectroscopy and electron spin resonance
spectroscopy. They are also developing new molecular structures by adding novel
surfactants to polymers. The polymers can then be folded to bring the
surfactants' hydrophobic regions together, forming a micelle, or artificially
ordered region, that would "suck up grease like a sponge," Professor
Somasundaran said.
Columbia will collaborate with Unilever Research to develop polyglucoside-
based antimicrobial agents that would dissolve the protective sheath around
bacteria. Such agents have been shown to adsorb well to titanium surfaces and
would provide an ideal sterile lubricant for implanted prostheses. ARCO and
Henkel Corp. will also help develop the sugar-based materials.
In addition to the polyglucosides, researchers at the center will develop
pyrrolidones, a class of five-membered ring hydrocarbons that are soluble in both
organic and inorganic compounds and thus are superior detergents. When a
small amount of pyrrolidone is added to oil that has particles suspended in it, for
example, the particles clump together, allowing purified oil to be removed from
the mixture. "A little bit of it performs magic with effluents containing
undesirable particles," Professor Somasundaran said. Columbia has filed a
patent application covering novel applications of N-alkyl-2-pyrrolidones.
Soaps are long-chain fatty acids that have been modified by strong bases,
which add hydroxyl ions that attract water. Early cultures discovered soaps when
fats dripped onto wood ashes that contain bases. During World War II, German
chemists formulated branched-chain synthetic soaps such as alkyl benzene
sulfonates, which, like soap, functioned well in hard water by precipitating the
calcium ions that make water hard.
Branched-chain synthetics, which microbes can't digest, caused foaming
in river water and in contaminated well water. So industry began producing
straight-chain alkyl benzene sulfonates, single chains of hydrocarbons attached to
a benzene ring and a sulfonate group, which are still the laundry workhorse. But
straight-chain synthetics don't efficiently precipitate calcium ions, so chemists
had to add phosphate softeners, which also caused the eutrification of lakes and
rivers. American companies now add water softeners such as sodium carbonate,
or washing soda, to laundry products.
This document is available at http://www.columbia.edu/cu/pr/. Working press may receive
science and technology press releases via e-mail by sending a message to [email protected].
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