news

    Important Notice on the use of our NanoAmando as seeding nuclei in the CVD diamond film syntheses

    Particle-size distribution of NanoAmando is the best in its aqueous colloidal solution, the first product in our series of the elementary particles of detonation nanodiamond, and grows larger as it is processed in our subsequent production steps. Hence it is recommend using the aqueous colloidal solutions for this purpose. However, the standard concentration of 2.5% is too high for this particular use, and it must be reduced to 0.2% by addition of water just before the use as follows. A prefixed amount (a ml) of the 2% mother solution is placed in a larger Erlenmeyer flask and 11.5a ml of pure water is slowly dropped from a dropping funnel under vigorous magnetic stirring and bubbling of nitrogen gas. The resulting solution is used immediately for seeding. The once used colloidal solution is discarded after the seeding. The reason for the apparently wasteful action is that the nanodiamond particles in 0.2% solution aggregate up to several 10 nm in size upon standing after seeding, due to °∆dilution aggregation°« phenomenon proper to the dilute solutions of detonation nanodiamond less than about 1% in concentration. Aggregates are naturally unsuitable for nucleation in the CVD process. In contrast, °∆concentration dispersion°« prevails in concentrations above 1%.

    The size of Elementary Particles of Detonation Nanodiamond (EPDND) decided at 2.6°ř0.5nm°™

    °°The only mass-produced artificial nanodiamond is being manufactured by a novel method of °∆detonation°«. This method has been known since 1963, but the true size of elementary particles of detonation nanodiamond (EPDND) remained unknown until recently. As the diamond crystals are basically isometric, they are usually quasi-spherical. If diameter is known, then we can estimate their surface area, and predict important properties originating from the surface. Hence it is desirable to know reliable diameter of EPDND.
    °°When we prematurely thought to have isolated the EPDND in 2005, we obtained an average DLS diameter of 4.8°ř0.8nm.°°In view of the large uncertainty in the DLS method, we used to express the diameter as 4〜5nm°•Although many people use this expression still now, the size of EPDND kept decreasing since then with the advance in isolation technique, and finally reached a seemingly final value of 2.6°ř0.5nm a few years ago. Needless to say, but the size of EPDND is fixed at a certain value when it is formed and we cannot change it during the disintegration-isolation process. However the observed size is profoundly affected by the ad hoc aggregation. Especially strong is the interparticle bonding in dimers which persists till the end of disintegration process. Unless we completely cleave off every dimer bond to leave only the monomers (namely elementary particles alone), the observed diameter exceeds the true diameter.
    °°Is the diameter of 2.6nm correct°©We need a good proof. The first proof came from unexpected direction. Highly reliable scientific report on the discovery of nanodiamond appeared in 1989 Nature written by R. N. Lewis and his group (Univ. Chicago), much later than the discovery of detonation nanodiamond. They isolated and confirmed nanodiamond from the famous Allende meteorite, believed to have been formed before the birth of solar system. They measured the size by TEM images to be exactly 2.6nm, perfectly identical with our DLS value! This coincidence is amazing but does not give a perfect proof because the relation between meteorite and detonation nanodiamonds is missing.
    °°The only acceptable proof, even though still indirect, would be to show by experiments that we always obtain exclusively those having average diameters within the 2.6°ř0.5nm size-range but never smaller ones. We recently finished an early stage of this endeavor and now it seems highly likely that we are right. Although we cannot disclose the details at this moment in order to protect our intellectual properties right, but will publish the results in due course.
    °°The surprisingly small diameter of EPDND suggests high potential in the future applications in various fields of material industry. For example, the surface density calculated from the diameter by using sphere approximation is 4,000 ≠÷/g, comparable with that of the best activated charcoal. In contrast, detonation nanodiamonds having diameters 4〜5 nm are composed of dimers and should have an effective surface area one digit smaller than the true EPDND.




    Publications of original papers and patents

    No. 352. °»Carbon structure in nanodiamonds elucidated from Raman spectroscopy,°… Korepanov, V.; Hamaguchi, H.; Ōsawa, E.; Ermolenkov, V.; Lednev, I. K.; Etzold, B. J. M.; Levinson, O.; Zousman, B.; Epperla, C. P.; Chang, H.-C., Carbon, 2017, 121, 322-329.

    No. 351. °»Unusual water hydrogen-bond network around hydrogenated nanodiamond,°… Petit, T.; Puskar, L.; Dorenko, T.; Choudhury, S.; Richter, E.; Burikov, S.; Laptinskiy, K.; Brustowski, Q.; Schade Ulrich, Yuzawa, H.; Nagasaka, M.; Kosugi, N.; Venerosy, A.; Girard, H.; Arnault, J.-C.; Ōsawa, E.; Nunn, N.; Shenderova, O.; Aziz, E. F. Accepted for publication J. Phys. Chem. C, in press.

    No. 350. °»Biocompatibility Assessment of Detonation Nanodiamond in Non-Human Primates and Rats Using Histologic, Hematologic and Urine Analysis,°… Moore, L.; Yang, J.; Lan, T. T. H. ; Ōsawa, E.; Lee, D.-K.; Johnson, W. D.; Xi, J.; Chow, E. K.-H.; Ho, D. ACS Nano 2016, 10, 7385-7400.


    Publications of review articles on the developments of nanodiamonds

    No. 215. °»Rediscovery and developments of 2.6nm diamond (in Japanese),°… Eiji Osawa°ĘNEW DIAMOND°Ę2017°Ę33°ĘNo.4°Ęp.11-15.
    No. 213. °»Nanodiamonds by detonation of explosives: formation and applications (in Japanese),°… Eiji Osawa°ĘPOWDER TECHNOLOGY (Funtai Gijutsu)°Ę2017°ĘVol. 9, No. 7, 577-583.


    Issues in the Detonation Reaction

    Issues in the Detonation Reaction(pdf)

    Preliminary announcement of our new product °»Fumed Diamond Powder°…

    ➋Preliminary announcement of our new product °»Fumed Diamond Powder°…(pdf)

    Characterization of NanoAmando has well-progressed°™

    ➊Characterization of NanoAmando has well-progressed°™(pdf)

    [Dec.}Forms of our new product, 2.6nm diamond particles

    °°Compared to our past product lines, the new 2.6nm diamond particles are more stable, and easier to handle. We began collecting physical constants and will soon provide detailed specifications, but as the first step standard concentrations are changed as follows:
    °°°° Aqueous colloidal solution­2.5 w/v %
    °°°° Soft hydrogel­about 13 w/v °ů
    The concentration of our major product, aqueous solution, is increased from the previous 2.0% to more stable level of 2.5%, taking into account of a new characteristic in the nanodiamond solution called °»Dilution Aggregation, Concentration Dispersion.°… This interesting phenomenon will be mentioned in some detail in our next news.

    [Dec.]Stable production of the elementary particles of detonation nanodiamond (EPDND)
    °°°°°°°°°°°°°°°°°°°°°°°°°° with an average diameter of 2.6nm achieved°™

    °°We have begun distributing single-nano diamond particles in 2006, but never been sure if our products are perfectly monodispersed primarily because the elementary particle of detonation nanodiamond (EPDND) was unknown. If the strongest-bound oligomers like dimers and trimers were still present even in small amounts, we should expect lognormal distribution (which we actually observe all the time) and the average or modal diameter could shift to a larger value. In the absence of any handy method to detect oligomers, we adopted quality engineering technique to optimize the beads-milling conditions and reach the smallest possible diameter value. To our surprise, average diameter of EPDND began decreasing from our old value in the 4 nm range, and reached to below 3nm in 2013 for the first time. A key factor was revealed to be tremendous increase in the number of diamond particles in going from micron-sized agglutinates to single-nano particles. We will reveal our new methodology to find the true size of EPDND. During 2016, the size-distribution almost constantly showed a narrow range of 2.6°ř0.4 nm. We now presume that complete disintegration of the agglutinates has been accomplished.
    °° The only problem remaining is to remove persistent contamination of zirconia nanoparticles (about 40 nm), which came from direct contact of the elementary diamond particles with the attritter media of zirconia, and are very difficult to remove by conventional chemical means. Although zirconia nanoparticles are generally harmless and non-toxic, and present in our nanodiamond product only in less than 0.01% on the number or volume basis, we are now testing several new methods of removing contamination and will soon finish purification.


    [Jan.]The second Nanodiamond Symposium-2014 MRS Spring Meeting in San Francisco

    NEWS

    °ý2014 MRS Spring Meeting in San Francisco
    The second Nanodiamond Symposium (No. PP) will be held within 2014 MRS Spring Meeting in San Francisco, CA, April 21-25, 2014, and at the moment is being organized by Eiji Osawa, Olga Shenderova (ITC, NC, USA), Joerg Wrachtrup (Uni. Stuttgart, Germany) and Vadym Mochalin (Drexel Uni., Philadelphia, USA). Technical program will be announced within January 2014. Professor Hisanori Shinohara, Nagoya Univ. was chosen as the flagpole plenary leacturer. The whole meeting is the largest of MRS Spring Meetings with 60 parallel symposia covering all the important topics of recent material science and technology and 6,000 people are expected to attend.

    °ýOne of the most promising companies
    NCRI was selected as one of the promising small companies in our locality. See °»The Most Outstanding 38 Small Companies in Nagano Prefecture,°… published by Asama Research Extension Center, December 2013, p. 30.


    °ýNano Tech 2014
    NCRI Joins Nano Tech 2014, Tokyo Big Site, January 29-31, 2014. Thanks to the courtesy of JST, we are given a small booth (No.°Ż8) within JST Domain (Area No. 6V-16) and exhibits the following items with posters and a short presentation on March 30:
    Skin Moisturing Gel Containing Nanodiamond Particles
    (1) Aqueous solution of nanodiamond colloid
    (2) Fourty 15 ml spray bottles of the colloid as hand-outs to the visitors.
    Non-oil Engine-Lubricating Liquid for Small Motors
    (1) Colloidal solution of nanodiamond in propylene glycol.
    (2) Fourty 15 ml spray bottles of the colloid as hand-outs to the visitors.
    Skii- and Snowboard Wax Containing Nanodiamond
    (1) Original ski-wax composites containing nanodiamond for both °∆Gelende°« and competing skiers and snowboarders.
    (2) Fourty 15g pieces of original wax containing nanodiamond for Gelende skiers as hand-outs to the booth visitors.

    These products are the results of our R&D project, °»Nanospacer Lubrication, a New Concept in Lubrication,°… sponsored by A-STEP, JST, 2012-2013.



    Conferences
    °ýThe 46th Fullerenes, Carbon Nanotubes and Graphene General Symposium, Univ. Tokyo, Hongo, March 3-5, 2014.
    °»Dispersion of detonation nanodiamond: A progress report,°… Shuichi Sasaki, Ryoko Yamanoi & Eiji Ōsawa (oral).

    °»Hydration of nanodiamond surface revisited: intercalation hypothesis,°… Ryoko Yamanoi, Shuichi Sasaki & Eiji Ōsawa (poster).

    °ý2014 MRS Spring Meeting, April 21-25, 2014, Muscone West, San Francisco, CA
    °»Nanospacer Lubrication: Re-designing a Friction Tester Working under Ultralow Load,°… Shuichi Sasaki and Eiji Ōsawa° Poster°ň.
    °»On the Possibility of Intercalation under the Graphitic Surface of Primary Particles of Detonation Nanodiamond (PPDND),°… Amanda Barnard, Dean Ho, Eiji Ōsawa, Shuichi Sasaki and Ryoko Yamanoi (Oral).

    Publications
    Accepted
    °»Three-dimensional model for phonon confinement in small particles: quantitative bandshape analysis of size-dependent Raman spectra of nanodiamonds,°… Korepanov, V. I.; Witek, H.; Okajima, H.; Ōsawa, E.; Hamaguchi, H. J. Chem. Phys.

    Appeared On-Line
    (1) °»The impact of structural polydispersity of the surface electrostatic potential of nanodiamond,°… Barnard, A. S.; Ōsawa, E. Nanoscale 2014, 6(2), 1188-1194.
    (2) °»Wigner energy of nanodiamond bombarded with neutrons or irradiated with ¶√ radiation,°… Cataldo, F.; Angelini, G.; Révay, Z.; Ōsawa, E.; Braun, T. Carbon DOI:10.1080/1536383X.2013.858131, posted online: 08 Jan 2014.

    Invited to contribute
    °»Plastics with intensities of metals,°… Ōsawa, E. Plastic Age, to appear in April, 2014, issue of Plastic Age, in Japanese.