A cobalt catalyst was manufactured using polyacrylonitrile (PAN)-based carbon fiber as a support. The surface of the fiber was covered with thin layer of alumina before cobalt impregnation. The catalyst was studied by a number of physicochemical methods including low-temperature nitrogen adsorption, TPR, DTG, chromatography, electron microscopy (TEM and SEM) and thermal conductivity measurements. The properties measured were discussed along with data on the activity in Fischer–Tropsch synthesis. It was found that the catalyst after the synthesis becomes significantly different from the starting catalyst, mostly because of the deposition and accumulation of high-molecular products of the Fischer–Tropsch synthesis. At the same time, in the steady-state mode, its catalytic parameters correspond to a high-performance granular catalyst based on graphite, which allows us to use the results obtained as a model for identifying the surface states of a porous catalyst of the new generation gas-to-liquid (GTL) process.

In this work, carbon-ceramic composite filaments have been manufactured and investigated. Carbon fiber UKN-12k based on polyacrylonitrile was used as a carbon core. The ceramic coating was produced from aluminum oxide. The production of composite filaments was carried out in the course of a repeatable multistage process, which included the preparation of an aqueous aluminum hydroxide sol, its deposition on a carbon base, and annealing of the resulting filaments in a flow reactor in an inert atmosphere (Ar) at a temperature that was about 1000 degrees C. It was confirmed by X-ray diffraction analysis that the resulting alumina ceramic coating consists exclusively of its a-phase. It should be noted that the presence of aluminum oxide on the carbon fiber surface protects the carbon core and increases the wettability, which significantly expands the possibilities of both application and modification of carbon fibers. According to thermogravimetric studies, it was found that this coating increases the thermal stability of the fiber in air, namely, it shifts the temperature of an active oxidation onset of by 120-150 degrees C up to 550 degrees C. It was also determined that at higher temperatures of 800-1000 degrees C, complete burnout of the carbon core is achieved, resulting in the formation of hollow ceramic fibers. According to the data of scanning electron microscopy, it was revealed that the inner diameter of the resulting fibers corresponds to the diameter that the inner diameter of the used carbon fiber and it is in a range of 5-7 mu m. It was found that a morphology of ceramic fibers repeats an external structure of a carbon precursor, which can be used to produce of both bundles and felt from hollow ceramic fibers, suitable for a manufacture of membranes, high-temperature filters and composite materials.

Epoxy nanocomposites with CNT "felt" obtained by float catalysis as filler were prepared. Such parameters as curing process and glass transition of epoxy nanocomposites and initial epoxy composition, structure and morphology of CNT "felt", initial epoxy composition and epoxy nanocomposites, specific capacity of epoxy nanocomposites were investigated. The influence of CNT "felt" on curing process in epoxy nanocomposites with different amounts of curing agent was determined. It was found that the presence of CNT "felt" leads to decrease in curing reaction rate for nanocomposites with a stoichiometric composition of the epoxy and curing agent. At the same time, CNT "felt" accelerates the curing reaction with an excess of curing agent. An exothermic reaction between the curing agent and the surface of CNTs was established. It was found that the structure of epoxy nanocomposites has a high degree of heterogeneity: the presence of fiber-like structures and individualized CNTs is observed together with the regions that are typical for CNTs that are fabricated via a catalytic chemical vapor deposition (CVD). Based on the studies performed, it is possible to predict that the uncured compositions already obtained in this work can be used for the manufacture of electrically conductive carbon fiber reinforced plastics and functional coatings.

The methodology for manufacturing composite catalyst supports comprising 50 wt.% exfoliated graphite by mold pressing was developed.The technique of wetting a relatively hydrophobic powder with liquid to obtain uniform paste for press machine was proposed and tested.The dependencies of the samples density on the compacting pressure were obtained.The structural characterization was done, i.e. specific surface area, porosity, micro-and mesopores volume, pore size distribution were measured.It was found that obtained samples have a specific surface area of about 340 m 2 /g, total pore volume of about 0.28 cm 3 /g at a true density of 2.3-2.5 g/сm 3 , practically regardless of compacting pressure in the range from 16 to 230 MPa.The thermal conductivity coefficients of the sample pressed at 230 MPa were 3.6 and 12.2 W/(m⋅K) along the cylinder axis and perpendicular to it, respectively.This anisotropy is due to specific preferential orientation of the heatconducting component.The composite reveals similar anisotropy in strength.The strength was measured as 39.4 and 87.6 N/granule along the axis of the granule and perpendicular to it, respectively.The results of the paper demonstrate that a contradictive task of combining high specific surface area, strength and thermal conductivity can be realized in one sample, which is important for catalysis applications.