Part 5: From the Softest Materials to the Hardest
Kistler’s Career Changes Course
By Dr. Mike Ayers, Lawrence Berkeley National Laboratory
In 1935, Sam Kistler left the University of Illinois and accepted a job at the Norton Company, a major producer of abrasive materials in Worcester, Massachusetts. In spite of the fact that he was asked to completely shift his research focus from soft, fragile aerogels, to hard, brittle grinding compounds, he flourished at Norton, eventually becoming its Director of Research. In fact, of Kistler’s many patents, the majority are related to grinding and polishing products. Ennis Anderson’s Faculty Profile from the University of Utah’s engineering magazine had this to say about Kistler’s time at Norton:
In the abrasive field, he had the good fortune to develop a process and product that has dominated a $20,000,000 segment of the industry for over fifteen years. Every large manufacturer of grinding wheels in the world is licensed under his patents, or is operating in countries where he did not file for patents.
In spite of the fact that, in later years, he was director of research and, therefore, could put only limited time in the laboratory, he kept his hands in research on his own ideas, from which came one product that sells now at the rate of $2,000,000 a year and improvements or dominating positions in several others that have contributed Ten years ago, importantly to the company’s prosperity, his patent attorney told him that he had fifty patents under his name. Inventing activity has continued; and, at present, he has six patents now pending, one of which has been filed for through the University on a process for strengthening glass; and already the Coming Glass Company has signed an exclusive licensing agreement, under which they must spend a minimum of $500,000 in developing the process.
Perhaps the most romantic of his undertakings the Norton Company was the effort to synthesize diamonds. He and associates succeeded, insofar as they know, in being the first to have ever produced diamonds; but, for reasons that are now clear to hindsight, they did not succeed in making them commercially. The company felt that it could not afford to continue the research and persuaded the General Electric Company to take up where they left off.
Indeed, Kistler appears to have worked on the original synthetic diamond project. It is this effort, as well as his invention of a scratch-resistant polymer for eyeglasses that are mentioned as his major research accomplishments in his “official” biographies, while his more enduring discovery of aerogels is sadly neglected.
Kistler’s interest in synthetic diamonds may have been with him throughout his entire career. In the background literature section of his Master’s theses he cites an early attempt to prepare diamond through crystallization of carbon from supercritical fluids:
As an outgrowth of his work with Hogarth on the critical state, Hannay carried out some interesting experiments on the solution of carbon in gaseous solvent and its precipitation as a crystalline form resembling diamond….
Hannay proposed to conduct his experiments at such high temperatures and pressures that glass was out of the question. He tried wrought iron tubes half an inch in internal diameter and two inches external diameter by twenty inches long. These he filled from one third to three quarters full of different hydrocarbons along with a few grams of either, potassium or lithium and welded the ends. The reason for the alkali metals was that he had found that, when they were heated to a high temperature with a hydrocarbon, they reacted with the hydrogen of the hydrocarbon liberating the carbon which under these conditions seemed to have a tendency to deposit in a harder form than usual, flakes being sometimes obtained that were hard enough to scratch glass. On the whole the tubes were too weak and so many burst that no conclusions could be drawn. He now had some tubes made three quarters of an inch internal diameter, four inches external diameter, end twenty inches long. These he filled with different proportions of a hydrocarbon, a distillate from bone oil, lampblack, and an alkali metal…
…Most of these experiments were also negative, nine tenths of the tubes either leaking or exploding. However, he succeeded in obtaining a few tubes that withstood the pressures produced… Upon cooling and cutting open the tubes some carbon deposits were found that were exceptionally hard, and in a few cases transparent crystals were found resembling diamond in formation…
The Norton Company’s project on synthetic diamonds was part of a multi-lab program under the direction of P.W. Bridgman of Harvard University. The development process was long and complicated, and it appears that Norton did not have the resources available to see it through. Eventually G.E. completed the work, and Norton’s contribution appears to have been minor, making Kistler’s much more successful discovery of aerogels stand out further among his many accomplishments.
In his Collected Experimental Papers, vol. VII, Bridgman had this to say about making diamonds in supercritical fluids and the eventually successful anvil methods:
One of the earliest and still most discussed attempts was by a Scotsman, J.B. Hannay, in 1880. He mixed hydrocarbons, “bone oil” and lithium, sealed the mixture in a wrought iron tube and heated it to redness in a forge. All but three of the 80 tubes exploded. (The pressure could not have been more than one or two thousand atmospheres.) In the residue of the unexploded tubes it was said that diamonds of density 3.5 were found. The claim was accepted at its face value and reported in the London Times by N. Story-Maskelyne. Subsequent attempts by a number of experimenters failed, however, to reproduce Hannay’s results.
The matter was reopened in 1943 by the discovery in a forgotten corner of the British Museum of a. small exhibit labeled “Hannay’s Diamonds.” These were analyzed with X-rays by F. A. Bannister and Kathleen Lonsdale, and found to be certainly diamonds, and of a somewhat rare type at that. On the theory that it was unlikely that diamonds fraudulently inserted would be of this rare type, Bannister and Mrs. Lonsdale argued that Hannay’s claim was probably genuine. But there was also contrary evidence, in particular, as pointed out by Lord Rayleigh, some known instances of bad faith on Hannay’s part. It seems to be the present consensus that Hannay was a fraud. Mrs. Lonsdale recently told me that she now also inclines to that view…
It is known that at atmospheric pressure diamonds start to change spontaneously to graphite when heated to somewhere in the neighborhood of 1,500 degrees C. This suggested that the reverse transition might run at the same temperatures if only the pressure could be raised high enough. The chances seemed good enough to justify a gamble on success, and early in 1941, largely through the interest of Zay Jeffries of the General Electric Company, General Electric’s Carboloy Department, the Carborundum Company and the Norton Company jointly entered into a five-year agreement with me to finance the construction of apparatus and the conduct of experiments. The experiments were to combine high temperatures with pressures up to the 30,000 atmospheres or more which I was able to control in the laboratory. A 1,000-ton press was purchased and set up in the Harvard Geophysical laboratory with the understanding that the apparatus could be used part-time for experiments in geophysics. Very shortly, however, we were immersed in the war. Material became slow and difficult to procure, personnel was not available, and altogether the apparatus was used for less than two years of carbon experimenting instead of the five contemplated…
At this juncture the five years of the agreement were up, the agreement was not renewed and the apparatus was removed to the Norton Company plant in Worcester. The Norton Company continued experiments of their own for the next five years. The results have been published only in part. It is known that the Norton workers synthesized a number of minerals of interest to geologists, including a brand-new- form of silica christened Coesite. There has been talk to the effect that occasionally diamonds were produced, but that the conditions of formation were obscure and could not be reproduced. It would appear from the outside that the probability is not high that these were genuine the conditions of thermodynamic stability were doubtless not attained, and X-rays, the only certain method, were not used in the analysis. at any rate, at the end of five years the Norton Company let it be known that they were through, and that if the problem was to be solved it would have to be by an organization with greater resources.