Comparison of ultradiamond and Mypolex: properties and processes.

Comparison of ultradiamond and Mypolex: properties and processes

We are often asked how ultradiamond50 and ultradiamond90 compare to Mypolex.

Mypolex, a relatively small synthetic diamond, is large and "blocky" compared to ultradiamond50 and ultradiamond90. Mypolex is a polishing agent suitable for use before final polishing with ultradiamond50 and ultradiamond90.

Below is a brief comparison of ultradiamond50/ultradiamond90 and Mypolex.

Property/Process	ultradiamond50	ultradiamond90	Mypolex [1]
Shape	Rounded [2]	Rounded [3]	"basic shape is blocky" "all particles have an extremely rough surface" [4] "every microdiamant product features the narrow particle size distribution and blocky shape that our name stands for" [5]
Size	Range 0.5 - 10 nanometer Average approximately 4 - 5 nanometer [6]	Range 2 - 10 nanometer Average approximately 4 - 5 nanometer [7]	Range 0 - 50 nanometer (smallest size available) [8]
Size reduced from as-made material?	No	No	Yes - by micronizing [9]
Starting material	a charge of an explosive, such as trotyl/hexogen (cyclotrimethylenetrinitramine ("RDX")) 60/40 an atmosphere containing 4 vol. % oxygen (the balance is nitrogen) ultradispersive carbon particles	ultradiamond50 (ultradiamond50 is treated by a chemical process to remove carbon and graphite from its outer shells)	Graphite [10] "graphite/copper mixture … pressed into pellets from a dried water slurry containing 2 per cent guar gum" [11]
Explosion method	an electric detonator	Conversion from ultradiamond50 to ultradiamond90 is not by explosion	"powders, powder compacts … in the form of a solid circular cylinder" "positioning the solid cylinder coaxially within a hollow circular metal cylinder with a spacing between the facing surfaces of the coaxial cylinders" "surrounding the convex surface of the hollow metal cylinder with a layer of detonating explosive" [12]

[1] "April 1, 1999 - DuPont today announced that it has sold its Industrial Diamond business to Mypodiamond Inc., a subsidiary of Spring Holding, AG of Switzerland. The business manufactures and markets Mypolex® polycrystalline diamond, a superabrasive used for surface improvements." DuPont news release.

[2] Based on TEM image (replica method); also see research on ultradiamond material in Ouyang Q, Okada K., Nano-Ball Bearing of Ultra-Fine Particles of Cluster Diamond., Applied Surface Science, 78, 309-313, (1994) - which states "… particles are in the shape of balls"

[3] Based on TEM image (replica method); also see research on ultradiamond material in Ouyang Q, Okada K., Nano-Ball Bearing of Ultra-Fine Particles of Cluster Diamond., Applied Surface Science, 78, 309-313, (1994) - e.g. title of TEM micrograph in Fig. 1 "… particles are in the shape of balls"

[4] "Unique Values of Du Pont MYPOLEX^® Diamond Powder in Polishing Superhard Materials. Presented at the 1988 Inter-Society Symposium Machining of Ceramic Materials and Components" American Society of Mechanical Engineers, American Ceramic Society, Abrasive Engineering Society, December 1, 1988. Prepared and presented by Niles F. Bailey, MYPOLEX Marketing Manager.

[5] Rudolf Spring AG website. (Rudolf Spring AG micronizes 0 - 50 nanometer Mypolex in Switzerland and lists it on the Rudolf Spring AG website - discussion with Kurt Spring, President and CEO of Rudolf Spring AG, August 2000)

[6] Measured by small-angle X-ray scattering. The X-rays measure the diamond center zone, excluding the relatively thin outer zones

[7] Measured by small-angle X-ray scattering.

[8] Discussion with Kurt Spring, President and CEO of Rudolf Spring AG, August 2000. (From the same discussion - in the past, as in the reference of footnote [4], incorrect Mypolex size data was reported by DuPont, such as a nominal range of 2 - 10 nanometers for grade N6, the smallest grade.)

[9] Discussion with Kurt Spring, President and CEO of Rudolf Spring AG, August 2000

[10] Discussion with Kurt Spring, President and CEO of Rudolf Spring AG, August 2000

[11] United States 1971 patent 3,608,014 - Example 1

[12] United States 1971 patent 3,608,014 - Description of the invention

As with all patents, the above patent information is generally, but not necessarily precisely, descriptive of the products and processes compared here.