Harry P. Gregor, a Columbia University chemist and leading authority on ion exchange and membrane separation technology, died Sunday (May 3) at St. Luke's Hospital in Manhattan. He was 81 years old.
He had enjoyed good health until very recently, when he suffered a series of strokes, which were the cause of his death, said his daughter, Polly Gregor, a research immunologist.
He was Professor Emeritus of Chemical Engineering and Applied Chemistry at Columbia's Fu Foundation School of Engineering and Applied Science, where he taught for 23 years, and Distinguished Research Professor at Polytechnic University, where he was conducting research for the U.S. Navy.
Professor Gregor was the first to recognize that certain ionic polymers attract small ions and reject larger ions. The technology is used to promote a number of chemical reactions that involve ions, such as removing calcium to soften water or removing radioactivity to purify water.
"He had a keen insight into how physical processes take place in aqueous solutions," said Carl C. Gryte, professor of chemical engineering and applied chemistry at Columbia and a student of Professor Gregor's. "He was a physical chemist first and a polymer chemist second."
Born Dec. 16, 1916 in Minneapolis, he received the B.A. magna cum laude in chemistry, physics and mathematics in 1939 and the Ph.D. in physical chemistry, biochemistry and physiology in 1945 from the University of Minnesota. His interest in membranes germinated in the laboratory of Karl Sollner, his dissertation advisor, who had done extensive work on ion-selective membranes. He held a postdoctoral appointment at the University of Minnesota from 1944 to 1945, which he used to study the problem of synthetic rubber, since the United States had lost its principal supply of rubber, the Philippines, in the war. He was made a captain in the U.S. Navy and was sent to Germany on several occasions after the war to evaluate the country's chemical industry.
He joined Brooklyn Polytechnic Institute as assistant professor of physical chemistry in 1946, and was eventually promoted to full professor. In 1967, he was named professor of chemical engineering and applied chemistry at Columbia and was named Professor Emeritus in 1987. He rejoined Polytechnic University in 1990 and was named Distinguished Research Professor.
In his early work at Polytechnic, Professor Gregor conducted basic research on ion exchange resins, gels that have a fixed negative charge. When exposed to solutions, the gels reach an equilibrium with the solution in which they attract cations, or positively-charged ions. But the gels prefer cations of small hydrated volumes, which Professor Gregor realized could be the basis for a purification technology. He developed several applications for the gels, among them removing radioactive materials from water and, during the strontium scare of the early 1960's, strontium-90 from milk. The U.S. Navy asked him to develop ion exchange resins to purify drinking water in case of a nuclear confrontation.
At Columbia in the late 1960s, he returned to membrane research and also conducted important work in polyelectrolytes, ion exchangers and polymer catalysis. He did pioneering research on stabilized enzymes, in which enzymes that speed a reaction are bound to polymeric hollow fibers, allowing reactions to take place as a liquid flows through a fiber wall and eliminating the need to recover the enzyme from the final product.
He developed a bipolar membrane that acts as a synthetic enzyme to split salt solutions back into their constituent acids and bases. A synthetic enzyme process he developed is also used in the production of high-quality plastics, said Fred Liu, a former student who is now president of Union Resources and Technology Co., Inc., a technology firm in Pittstown, N.J.
Professor Gregor was also interested in biomass conversion, the fermentation of natural starches such as that found in corn to produce ethanol, which could be used to replace petroleum fuels in automobiles. He worked on membranes with high selective permeability to ethanol, in the hope they would make biomass conversion a more economic process. He was an advisor to the Department of Energy on its Alcohol Fuels Program and a member of the Columbia University Seminar on Biomaterials, and wrote letters and op-ed pieces in newspapers to promote biomass technology.
His most recent work, at Polytechnic, was on nonfouling membranes, which would repel particles that would otherwise foul the membrane. The membranes have been tested by the Navy for use in purifying wastes aboard ships.
Professor Gregor was the author of more than 165 research publications and four books, and held 25 U.S. patents with many foreign counterparts. He was a consultant to a number of corporations; at Allied Chemical Corp., he started the Membrane Application Laboratory, with Dr. Liu and with Eli Pierce, now University Professor at Polytechnic. He was also an advisor to government officials on a number of environmental problems, including designation of Superfund sites and environmental cleanups.
He is survived by his wife of 57 years, Elinor, of High Falls, N.Y.; a sister, Mary Molner of Las Vegas, Nev.; four children, all New York City residents, Laurel Porter, Charles, John and Polly; seven grandchildren and one great-grandson.
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 rjn2@columbia.edu.
5.5.98	19,343