IDEA #2SPK04 Metal-Graphite Nanocomposite Materials Of Different Functional Destinantion

THE SCIENCE AND TECHNOLOGY CENTER IN UKRAINE Fig. 1. Parts of TEG%Ni (а) and ultra%disperse graphite %Со (б) powders to METAL%GRAPHITE NANOCOMPOSITE MATERIALS OF DIFFERENT FUNCTIONAL DESTINANTION Description We are working out the production technologies for nanocomposites on the base of thermoexfoliated graphite (TEG) with the fixed transition metal (Fe, Co, Ni) parti(cid:28) cles 50–100 nm in size, which are considered to be suitable for application as energy storage, magnetic switches, opti(cid:28) cal filters, elements of space communication devices and catalysts of chemical reactions. The properties of carbon constituent (low density, resistance against the action of aggressive media, ecological safety, high electric and heat conductivity) and peculiar characteristics of the nanoscaled metallic component are combined harmonious(cid:28) ly in these materials. In particular, composite material acquires ferromagnetic properties if transition metal nanoparticles are fixed on carbon surface. Reasoning from the comprehensive investigation of the correlation between technological parameters of synthesis, structure and morphology of the graphite supporter, structural pecu(cid:28) liarities of the metallic component and their influence on the physical and chemical properties of the produced com(cid:28) posite materials we have created a series of the technolog(cid:28) ical procedures for graphite(cid:28)metal NCM synthesis: – chemical deposition from the water(cid:28)salt solutions with the subsequent salt thermolysis; – reduction of the intercalated C8K compound by the transition metal chlorides, which allows to obtain NCM with metal situated between graphite layers in a form of atomically distributed metal and on the graphite surface in a form of nanoscaled particles; – thermal vacuum deposition of the metals. Graphite(cid:28)metal NCMs of different functional destination have been obtained using these procedures, for example: – TEG(cid:28)Fe(cid:28)Co(cid:28)Cu oxide system NCM, which application as catalysts allowed to reduce the temperature of CO to CO2 100% transformation down to 152°C and to increase the velocity of oxidizing during 100% transformation at 150°C up to the values of (10–30)⋅10(cid:28)6 mole/s⋅g, that is tenfold higher as compare that using bulk Сu2(OH)3NO3 catalyst; – graphite(cid:28)Co(cid:28)Fe NCMs, which application as catalysts for the reaction of the ammonia synthesis allowed to reduce the temperature of the reaction start (by 100°С), а also to increase by two orders the velocity of N2 and H2 mixture transformation into ammonia. Now the creation of the technological procedures for production of the nano(cid:28) disperse carbon material(cid:28)metal NCMs, which will contain carbon nanotubes, fullerens and ultra(cid:28)disperse natural graphite as nanoscaled carbon constituent, is carried out. Another direction of our activity is the creation of graphite(cid:28)metal NCMs containing polymer binder that essentially improves NCMs' technological parameters and widens the areas of its application. TEG(cid:28)polymer and TEG(cid:28)metal(cid:28)polymer application is shown to be promising for the production of protective shields against electro(cid:28) magnetic radiation: so, for TEG(cid:28)epoxy insertion attenua(cid:28) 48 tion (losses) at 1.8 GHz frequency was about 25 dB. Innovative Aspect and Main Advantages The application of the super(cid:28)disperse forms of graphite, in particular, thermoexfoliated graphite, graphite films, nan(cid:28) otubes, which possess highly developed surface. Compacting ability of thermoexfoliated graphite allows to produce bulk nanocomposite materials of the prescribed shape. The metal or its compound deposited onto graphite is nano(cid:28)crystalline (50–100nm), uniformly distributed on the surface of the disperse graphite particles and, respec(cid:28) tively, in the bulk of the compacted composite material. The variation of the metallic component, its dispersity and topology allows to obtain nanocomposite materials pos(cid:28) sessing peculiar physical properties, which are conditioned just by nano(cid:28)dimensionality of the metal. Deposition of the metallic component passes within the integrated techno(cid:28) logical cycle with disintegration of the graphite con(cid:28) stituent. Our elaborations are secured by Patents of: Device for the production of thermoexfoliated graphite (2001); The method of the production of the metallized thermoexfoliated graphite (2001); The method of the pro(cid:28) duction of the catalyst for purifying technological gases from carbon monoxide (2004). Areas of Application Catalysts for the reactions of ammonia synthesis and oxi(cid:28) dizing of the carbon monoxide: TEG(cid:28)(Fe(cid:28)Co), TEG(cid:28) Fe(cid:28) Co(cid:28)Cu oxide system.Elements of the magnetic circuits: TEG(cid:28)Co (and Co(cid:28)Fe compounds). Magnetic switches: TEG(cid:28)Co (and Co(cid:28)Fe compounds). Magnetic sensors: TEG(cid:28)Со. Anode material for lithium ion batteries: ТEG(cid:28) Sn(Sn(cid:28)Sb) Material for protective shield against electro(cid:28) magnetic radiation: TEG, TEG(cid:28)metal, TEG(cid:28)polymer. Stage of Development Technological schemes and scientifically grounded recom(cid:28) mendations concerning selection of the optimum techno(cid:28) logical regimes for production of graphite(cid:28)metal NCMs by different methods. A laboratory set of graphite(cid:28)metal NCMs specimens has been produced. Contact Details D.Sc. Matzui Lyudmila Taras Shevchenko National University 01033, Kyiv(cid:28)33, Volodymyrska st., 64, Ukraine Phone: (including code) +380(cid:28)44(cid:28)526(cid:28)23(cid:28)84 E(cid:28)mail: matzui@univ.kiev.ua SCIENCE AND INNOVATION. Special Issue, 2007