Formation Of Carbon Nanotubes Research Articles

TECHNOLOGY FOR OBTAINING CARBON NANOCOMPOSITE MATERIALS

The kinetics of the formation of carbon nanotubes on a catalyst during the pyrolysis of carbon-containing gases is rather peculiar and little studied. Its main provisions proposed in the literature are debatable. The complexity of studying the kinetics of NT synthesis is confirmed by the use of about 10 parameters when creating a model. The kinetic regularities of the formation of carbon nanotubes during the pyrolysis of methane are studied in terms of the yield of carbon at the optimal composition of the catalyst.

Controlled formation of carbon nanotubes incorporated ceramic composite granules by electrostatic integrated nano-assembly.

Controlled incorporation of carbon nanotubes (CNT) with alumina (Al2O3) and zirconia (ZrO2) nanoparticles using an electrostatic nano-assembly method for the fabrication of homogeneous CNT-incorporated Al2O3-ZrO2 and CNT-incorporated shell-layer Al2O3-ZrO2 composite granules is demonstrated. The spark-plasma-sintered CNT-incorporated shell-layer Al2O3-ZrO2 artifact exhibited approximately 15 times higher electrical conductivity than a homogeneous CNT-incorporating artifact. This novel composite granule fabrication method using an electrostatic integrated assembly of colloidal nanomaterials would be beneficial for the development of multiscale and multicomponent composite materials.

The Role of Chain Processes in Cool Flames and Soot Formation

The 125th anniversary of Academician N.N. Semenov, the great natural scientist of the 20th century, is a significant event for the world scientific community. With his discoveries and tireless scientific, organizational, pedagogical, and social activities, he made an invaluable contribution to the formation of chemical physics and to the development of physics, chemistry, and biology. Nobel Prize laureate, academician N.N. Semenov played a huge role in the creation of the Department of Chemical Kinetics and Combustion of the Al-Farabi Kazakh National University and the Institute for Problems in Combustion. Contacts with the disciples of Academician N.N. Semenov made it possible for the researchers of the Institute for Problems in Combustion to discuss their candidate and doctoral dissertations at the seminars of the Institute of Chemical Physics in Moscow. With the support of N.N. Semenov, Ya.B. Zel’dovich, and A.G. Merzhanov, All-Union Symposia on Combustion and Explosion (1980 in Alma-Ata) and on Structural Macrokinetics (1984 in Alma-Ata) were organized. The article provides an overview of the author’s works on studying the structure of the front of cool flames of diethyl ether and butane, the preflame zone of normal propane flames, and soot formation during combustion of hydrocarbons. The phenomenology, kinetics and mechanism of soot formation, and the influence of various factors on the formation of polycyclic aromatic hydrocarbons, carbon nanotubes, fullerenes, graphene, and soot are considered.

Green synthesis of carbon nanomaterials from sugarcane bagasse using bio-silica supported bimetallic nickel-based catalysts

Sugarcane bagasse (SCB) can be considered as an inexpensive and abundant source for the production of valuable carbon nanomaterials (CNMs). Herein, the synthesis of CNMs via sugarcane bagasse (SCB) pyrolysis was investigated using a simple two-stage process. Bio-silica extracted from rice husk (RH-SiO2) was loaded with 50%Ni, 40%Ni-10%Cu, 40%Ni-10%Mo, and 40%Ni-10%Co and evaluated as catalysts for the production of CNMs from pyrolysis products. The fresh catalysts were characterized by XRD, H2-TPR, and CO2-TPD analyses, while the spent catalysts were characterized using TEM and Raman spectroscopy. The XRD and TPR results of the fresh catalysts demonstrated the existence of non-interacted NiO species in the monometallic Ni/RH-SiO2 catalyst. However, mixed oxides of NixCu1-xO, NiMoO4, and NiCo2O4 species were presented in Ni-Cu, Ni-Mo, and Ni-Co catalysts, respectively, in addition to non-interacted NiO species. TEM images revealed the presence of both carbon nanotubes (CNTs) and graphene nanosheets (GNSs) depending on the catalyst type. The results showed that the presence of mixed oxide species in the catalyst was associated with CNTs formation, while the existence of agglomerated Ni particles was correlated to GNSs formation. The catalytic activity of the catalysts in terms of carbon yield was arranged as follows: 50%Ni > 40%Ni-10%Co > 40%Ni-10%Cu > 40%Ni-10%Mo. Raman spectra proved the production of high-quality CNMs using all Ni-based catalysts.

Steam reforming of acetone and isopropanol: Investigation of correlation of ketone and alcohol functional groups with properties of coke

Ketones and alcohols are important fractions of bio-oil, and their steam reforming might generate the coke of varied properties and impacts on catalyst. In this study, acetone and isopropanol were selected as a model compounds of the biomass-derived oxygenated organics for steam reforming over a Ni/KIT-6 catalyst, with the particular focus on the potential correlation of the properties of coke with the main functionalities of the reactants. The results indicated that the steam reforming of acetone and isopropanol generated the distinct reaction intermediates that further differentiated properties of the coke formed. The steam reforming of acetone produced the reaction intermediates bearing the carbonyl functionalities that could involve in the condensation reactions, and the resulting carbonaceous species could also retain the oxygen-containing functionalities. This made the coke in acetone reforming aliphatic, thermally unstable, reactive towards oxidation. Furthermore, the high reactivity of the carbonyl-containing intermediates from acetone reforming also resulting in the formation of coke in carbon nanotubes form with thick walls, low inner diameters and course surface. In comparison, the steam reforming of isopropanol generated abundant reaction intermediates bearing with the CC functionality, making the resulting coke more aromatic, thermally stable and the formation of carbon nanotubes with thin walls and smooth surface.

Formation of coal-based carbon nanotubes by Fe-K catalyst

Carbon nanotubes were successfully synthesized by Fe-K catalytic pyrolysis of coal. The co-pyrolysis of coal and ferrocene can only form fewer carbon nanotubes due to the few available carbon sources. Potassium carbonate can significantly eliminate the defects in the plane between the basic structural units of coal and promote the formation of carbon nanotubes, but its catalytic graphitization effect was limited when potassium carbonate was dry mixed with coal. In addition, the results show that Fe and K had a synergistic effect. Fe atoms and C atoms formed Fe-C solid solution during pyrolysis, K-based catalyst etched amorphous carbon atoms of coal, and finally Fe-K co-catalyzed the growth of a large number of carbon nanotubes with a higher degree of graphitization. The catalytic pyrolysis process had great impact on the aromatic structure and oxygen-containing functional group structure, but slight impact on the aliphatic structure of coal. The molten state of the catalyst during pyrolysis and its affinity for amorphous carbon was higher than that of graphitic carbon, leading to the migration of the catalyst and the change of crystal plane, which may be the reason for the formation of "carbon nanofiber-tube".

Binary metal oxide anchored into dense N-doped CNTs arrays: Concerted pseudocapacitance and diffusion behavior for long-cyclic Li-ion half/full batteries

Electrode material is a crucial role to improve the performance of alkali metal ion batteries. Herein, a hierarchical nanosheet of binary metal oxide (ZnO/Co3O4) anchored into dense N-doped CNTs arrays (ZCO/NCNTs) was derived by two-step calcination. The design of ZCO/NCNTs containing binary metal oxides can better coordinate the pseudo-capacitance behavior of Co3O4 and the ion diffusion behavior of ZnO to realize a long-term stability for lithium storage at various current densities. Furthermore, the presence of slight Zn sources increases the catalytic efficiency of Co towards the growth of graphitized carbon during calcination process, resulting in the formation of dense carbon nanotubes for enhanced carrier transport. The strong interaction between the metal oxides and carbon nanotubes can accommodate the bulk expansion of electrode, obtaining high reversible capacity (∼880 mAh g−1) and long cycle stability (>500 cycles). Thus, the full cell of LiFePO4||CZO/NCNTs at 0.3 A g−1 exhibits excellent cycle stability with good retention rate after 200 cycles. This study provides a new basis for the improvement of lithium storage performance of metal oxide anode.

Formation of Carbon Nanotubes and Microsilica during the Production of Crystalline Silicon in Three-Phase Ore-Thermal Furnaces

Formation of Carbon Nanotubes and Microsilica during the Production of Crystalline Silicon in Three-Phase Ore-Thermal Furnaces

Rheological, electrical, and dynamic thermomechanical properties: Comparison between multiwall and double-wall carbon nanotubes in polylactide and polyamide 11

In this study, multiwall carbon nanotubes (MWCNTs) and double-wall carbon nanotubes (DWCNTs) have been dispersed in polylactide (PLA) and polyamide 11 (PA11) using an internal mixer. Rheological characterization confirmed the formation of carbon nanotube (CNT) networks in PLA and PA11 attributed to well-dispersed CNTs in the respective matrices. A lower rheological percolation threshold of PLA/MWCNT nanocomposites (less than 0.5 wt. %) compared to PA11/MWCNT nanocomposites (about 2 wt. %) confirmed the greater affinity of CNTs for PLA. The threshold for DWCNTs was below 0.5 wt. % in PLA and between 0.5 and 1 wt. % in PA11. PLA-based nanocomposites also showed higher electrical conductivity values compared to PA11-based nanocomposites. Nanocomposites containing DWCNTs exhibited higher electrical conductivities compared to those containing MWCNTs due to the higher aspect ratio of DWCNTs. Dynamic mechanical thermal analysis showed enhanced storage modulus values and reduced damping behavior with increasing content of CNTs for both polymers.

Promoting Role of Amorphous Carbon and Carbon Nanotubes Growth Modes of Methane Decomposition in One-Pot Catalytic Approach

We report the simultaneous production of hydrogen fuel and carbon nanotubes (CNTs) via methane dehydrogenation catalyzed with Ni/SBA-15. Most Ni nanoparticles (NPs) with size between 10 and 30 nm were highly dispersed on SBA-15 and most of them had a strong interaction with the support. At temperatures ranging from 500 to 800 °C, methane could be decomposed to release hydrogen with 100% selectivity at conversion between 51 and 65%. There was no CO or CO2 detectable in the reaction fluent. In the initial stage of the reaction, amorphous carbon and dehydrogenated methane species adsorbed on the Ni NPs promoted the CH4 decomposition. The amorphous carbon atoms were then transformed into carbon nanotubes which chiefly consisted of a multiwall structure and grew towards different orientations via a tip-growth or a base-growth modes, controlled by the interaction strength between the Ni NPs and the SBA-15 support. Reaction temperature affected not only methane conversion, but also the diffusion of carbon atoms on/in the Ni NPs and their precipitation at the interfaces. At higher temperature, bamboo-like CNTs or onion-like metal-encapsulated carbons were formed, mainly due to the rate of carbon atom formation greater than that of carbon precipitation for CNTs construction. The CNTs formation mechanisms are discussed and their growth modes under different conditions are proposed.

Effect of heat treatment on the morphology of carbon fibers doped with Co2p nanoparticles

Carbon fibers (CFs) decorated by Co2P nanoparticles and carbon nanotubes were prepared via needle-less electrospinning technique. Formation of catalytically active Co2P nanoparticles and growth of carbon nanotubes were monitored in open and closed sintering environment at different sintering exposure times. Higher porosity, important in the catalytic reaction for easier penetration of electrolyte into the CFs, was achieved by mixing two immiscible polymers with natrium dodecyl sulfate and subsequent heat treatment process. Structure and morphology of the prepared modified carbon fibers were characterized by XRD, SEM and TEM. The time of heat exposure at the sintering temperature of 1200 °C and closure of the sintering space showed distinct effect on the growth and shape of carbon nanotubes. SEM and Raman spectroscopy revealed that closure of the system led to the formation of carbon nanotubes with smaller diameters and less structural disorder. Comparing of as-prepared CFs revealed that CFs with Co2P sintered in the closed system exhibited the best electrocatalytic activity for hydrogen evolution reaction due to lower overpotential and smaller Tafel slope in acidic solution.Graphic abstract

Grafted nickel-promoter catalysts for dry reforming of methane identified through high-throughput experimentation

High-throughput synthesis of a series of monometallic and bimetallic catalysts (45 bimetallic and 50 monometallic samples) consisting of nickel and one of nine different metal promoters (B, Co, Cu, Fe, Mg, Mn, Sn, V and Zn) supported on one of five different metal oxides (alumina, ceria, magnesia, silica and titania) is carried out via organometallic grafting using a robotic platform. The catalysts are evaluated for their activity and selectivity for the dry reforming of methane at a feed ratio of CH4:CO2 of 1 at 650–800 °C in a parallel flow reactor system. The type of oxide support prevails over the type of additive for both catalyst activity and stability. On Al2O3 and MgO, Fe was found to be the best promoter; on SiO2, Cu is the best promoter at 700 °C and higher, while on TiO2, Mn is found to enhance the conversion at 800 °C. On CeO2, all additives except Fe have beneficial effects. Twenty-five catalysts show > 90% methane conversion with ten catalysts showing > 95% conversion at 800 °C with the H2:CO ratios ranging from 0.8 to 1.2. Amongst the ten highest performers, NiFe/Al2O3 and NiFe/MgO are more active than Ni/Al2O3 and Ni/MgO, respectively and were stable over a period of 25 h at 800 °C. Characterization on the as-prepared samples reveals highly dispersed phase, while after reduction in H2, highly dispersed and reduced nickel particles up to 10 nm are formed. The particles do not increase in size under dry reforming reaction conditions at 800 °C. An increased hydrogen consumption observed during H2-TPR of the nickel particles is positively correlated with methane conversion for Al2O3-based catalysts. The resistance to deactivation by coking and variation in coke structure are investigated by spectroscopic and microscopic methods to identify the relationship between metal promoters, alloy formation, and type of surface carbon deposits. Carbon whiskers were observed on the ten selected spent samples and are preferentially deposited on Ni rather than on the promoters. Carbon nanotube formation and metal particle removal from support were not observed to cause deactivation while amorphous carbon formation was clearly linked to catalyst deactivation, as amorphous carbon could encapsulate Ni, either on the support or at the end of the carbon nanotube. The organometallic grafting technique is an efficient and suitable technique for synthesizing highly dispersed and homogeneous phases which lead to high conversion and high durability for dry reforming of methane.

Carbon Microsphere-Supported Metallic Nickel Nanoparticles as Novel Heterogeneous Catalysts and Their Application for the Reduction of Nitrophenol.

Nickel nanoparticles are gaining increasing attention in catalysis due to their versatile catalytic action. A novel, low-cost and facile method was developed in this work to synthesize carbon microsphere-supported metallic nickel nanoparticles (Ni-NP/C) for heterogeneous catalysis. The synthesis was based on carbonizing a polystyrene-based cation exchange resin loaded with nickel ions at temperatures between 500 and 1000 °C. The decomposition of the nickel-organic framework resulted in both Ni-NP and carbon microsphere formation. The phase composition, morphology and surface area of these Ni-NP/C microspheres were characterized by powder X-ray diffraction, Raman spectroscopy, scanning electron microscopy and BET analysis. Elemental nickel was found to be the only metal containing phase; fcc-Ni coexisted with hcp-Ni at carbonization temperatures between 500 and 700 °C, and fcc-Ni was the only metallic phase at 800–1000 °C. Graphitization and carbon nanotube formation were observed at high temperatures. The catalytic activity of Ni-NP/C was tested in the reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride, and Ni-NP/C was proved to be an efficient catalyst in this reaction. The relatively easy and scalable synthetic method, as well as the easy separation and catalytic activity of Ni-NP/C, provide a viable alternative to existing nickel nanocatalysts in future applications.

Formation of carbon nanotubes and microsilica when obtaining crystalline silicon in three-phase electric ore smelting furnaces

The volume of silicon waste generated annually in the Irkutsk Region is 20 thousand tons per year, and the volume of waste accumulated in three sludge fields of JSC «Silicon» exceeds 3 million m3. The main type of crystalline silicon production waste is dust from gas cleaning systems of electric ore smelting furnaces. In this regard, this paper studies its chemical composition and the possibilities of using valuable components (amorphous silica, carbon nanotubes (CNT)) included in its composition. The study demonstrates that it is possible to separate this product by flotation into 3 components — sand fraction, flotation tailings enriched in SiO2, and froth enriched in carbon in the form of CNT. The structure of carbon nanotubes was studied and their physical and mechanical properties were determined: elastic modulus (2000 GPa), tensile strength (75 GPa), and thermal conductivity (4000 W/(m·K)). The amount of heat required to obtain 1 kg of CNT in electric ore smelting furnaces was calculated. Based on the material balance of commercial silicon electric smelting, it was found that 153 kg of CNT and 336 kg of flotation tailings are formed per ton of crystalline silicon during the endothermic process. Flotation tailings consist of 75 % amorphous microsilica particles. According to heat effect and Gibbs energy calculations made for amorphous microsilica formation reactions, it was found that all processes are exothermic, and the process of solid silicon carbide particles (2SiC + 3O2 → 2SiO2 + 2CO) oxidation with air oxygen has the highest thermodynamic probability. The economic efficiency of using amorphous silica to produce casting silumins was calculated, and its results clearly demonstrate a quick payback period (6 months), as well as a high level of its profitability (USD 819672).

Bimetallic MOF-derived CoSe2 embedded within N-doped carbon with enhanced lithium storage properties

Transition metal selenides are considered to be a potential anode material for lithium-ion batteries (LIBs) owing to their excellent electronic conductivity and high theoretical capacity. However, the application of transition metal selenides electrodes is still limited by their large volume expansion and sluggish kinetics during cycling. Herein, CoSe2 nanoparticles embedded in N-doped carbon nanotubes (CNTs) and carbon layer (CoSe2@NC) were constructed by pyrolysis of CoZn-based zeolitic imidazolate framework (CoZn-ZIFs) and melamine mixtures followed by selenization. During the pyrolytic process, the volatilization of zinc derived from CoZn-ZIFs, the retardation of the complete decomposition of g-C3N4 derived from melamine by Zn species played important roles in the formation of enriched N-doped carbon nanotubes (CNTs) and amorphous carbon layer. As a result, CoSe2@NC could show a large reversible lithium-ion storage capacity of 395 mAh g−1 at 0.5 A g−1 over 200 cycles, good rate capabilities of 367 mAh g−1 even at 2 A g−1, which outperformed CoSe2@NC-1 and CoSe2@NC-2 derived from carbonization of Co-Zn-ZIFs and Co-ZIF/melamine precursors followed by selenization, respectively. The enhanced lithium storage performance of CoSe2@NC could owe to the unique structure, where the N-doped CNTs and amorphous carbon layer can provide a rapid electron transfer channel and enable surface-dominated pseudocapacitive lithium storage, and the robust interface between CoSe2 and carbon can also effectively alleviate the volume expansion and enhance the integrity during the charge-discharge process.

Determination of the effect of carbon nanotubes on the microstructure and functional properties of polycarbonate-based polymer nanocomposite materials

Polymer nanocomposites are widely used in various high-tech industries. Due to the combination of the elasticity of the matrix and the strength of the inorganic filler, they have improved functional characteristics compared to unfilled polymers. The article is devoted to determining the effect of carbon nanotubes (CNT) on the microstructure and properties of polymeric nanocomposite materials for 3D printing based on polycarbonate. As a result of this work, a series of composite materials was manufactured using a piston extruder. Their microstructure and functional characteristics were investigated using methods of optical microscopy, thermophysical, electrical and mechanical analysis. It was found that CNTs form clusters in the polymer matrix, which form a percolation network at a content of 0.5–0.8 %. This feature of the structure formation of CNTs provided an abrupt increase in the functional characteristics of the materials obtained. It is shown that with an increase in the filler content in the system to 3 %, the thermal conductivity rapidly increases to 1.22 W/(m∙K). A similar effect is observed for the electrical conductivity, which increases by seven orders of magnitude from 10-12 to 10-5 S/cm at 3 % CNT content in the system, exhibiting percolation behavior. With the introduction of CNTs, the crystallinity degree of the polymer matrix decreases by almost 15 %, due to the fact that the developed surface of the nanotubes creates steric hindrances for polycarbonate macromolecules. This effect almost negates the reinforcing effect of nanotubes; therefore, the mechanical tensile strength with the introduction of 3 % CNTs increases by only 21 % compared to the unfilled matrix. In terms of their functional characteristics, the obtained materials are promising for the creation of filaments for 3D printing on their basis.

Solution‐Processable Carbon Nanotube Nanohybrids for Multiplexed Photoresponsive Devices

AbstractHere, the formation of carbon nanotube (CNT)‐based nanohybrids in aqueous solution is reported, where DNA‐wrapped CNTs (DNA‐CNTs) act as templates for the growth of PbS and CdS nanocrystals, toward the formation of PbS‐DNA‐CNT and CdS‐DNA‐CNT heterostructures. Solution‐processed multiplexed photoresponsive devices are fabricated from these nanohybrids, displaying a sensitivity to a broad range of illumination wavelengths (405, 532, and 650 nm). The DNA‐CNT and CdS‐DNA‐CNT devices show a drop in the current while PbS‐DNA‐CNT's current increases upon light illumination, indicating a difference in the operational mechanisms between the hybrids. Furthermore, the ON/OFF photoresponse of PbS‐DNA‐CNT is only 1 s as compared to 200 s for the other two nanohybrid devices. The mechanisms of the different photoresponses are investigated by comparing the performance under an inert and air atmosphere, and gate dependence device analysis and transient absorption spectroscopy measurements are also conducted. The results reveal that photoinduced oxygen desorption is responsible for the slower photoresponse by DNA‐CNT and CdS‐DNA‐CNT, while photoinduced charge transfer dominates the much faster response of PbS‐DNA‐CNT devices. The strategy developed is of general applicability for the bottom‐up assembly of CNT‐based nanohybrid optoelectronic systems and the fabrication of solution‐processable multiplexed devices.

Insights into the Reaction Routes for H2 Formation in the Ethanol Steam Reforming on a Catalyst Derived from NiAl2O4 Spinel

This work describes the satisfactory performance of a Ni/Al2O3 catalyst derived from NiAl2O4 spinel in ethanol steam reforming and focuses on studying the prevailing reaction routes for H2 formation in this system. NiAl2O4 spinel was synthesized using a coprecipitation method and reduced at 850 °C to obtain a Ni/Al2O3 catalyst. The spinel structure and catalyst were characterized using XRD, TPR, N2 physisorption, NH3 adsorption and TPD, TPO, SEM, and TEM. The experiments were carried out in a fluidized-bed reactor at 500 or 600 °C and different space-time values, using pure ethanol, ethanol–water, pure ethylene, or ethylene–water feeds. The reaction takes place through two paired routes activated by each catalyst function (metal and acid sites) whose extent is limited by the selective catalyst deactivation. The results evidence that at the beginning of the reaction the main route for the formation of H2 and carbon (nanotubes) is the dehydration of ethanol on acid sites followed by decomposition of ethylene on the Ni–Al2O3 interface. This route is favored at 500 °C. After the rapid deactivation of the catalyst for ethylene decomposition, the route of H2 formation by steam reforming of ethanol and water gas shift reactions over Ni sites is favored. The morphology of the carbon deposits (nanotubes) allows the catalyst to maintain a notable activity for the latter pathways, with stable formation of H2 (during 48 h in the experiments carried out). At 600 °C, the extent of the gasification reaction of carbon species lowers the carbon material formation. The high formation of carbon material is interesting for the coproduction of H2 and carbon nanotubes with low CO2 emissions.

The structural effect of Ni/ZrO2 on the formation and the reactivity of the carbon formed from methane decomposition

In this work, the structural effect of the plasma decomposed Ni/ZrO2 catalyst and the thermally calcined Ni/ZrO2 catalyst on the formation and the reactivity of the carbon formed from methane decomposition was investigated. The plasma prepared Ni/ZrO2 catalyst possesses smaller Ni particle size with Ni (111) as the principally exposed facet, which favors the formation of the carbon with enhanced reactivity towards carbon dioxide. The Ni (111) facet benefits the formation of carbon nanotubes (CNTs) attached to Ni nanoparticles at the top and suppresses the formation of onion-like carbon which encapsulates Ni active sites. Besides, CNTs on the plasma-treated catalyst show smaller diameter sizes with lower graphitization degree, which are easier to be converted. Therefore, the plasma prepared catalyst presents a higher carbon resistance. The present work well explains the improved activity and stability of the plasma prepared Ni/ZrO2 catalyst for CO2 reforming of methane.

The structure of carbon nanotubes in a polymer matrix

We carried out an analytical structural analysis of interfacial effects and differences in the reinforcing ability of carbon nanotubes for polydicyclopentadiene/carbon nanotube nanocomposites with elastomeric and glassy matrices. In general, it showed that the reinforcing (strengthening) element of the structure of polymer nanocomposites is a combination of the nanofiller and interfacial regions. In the polymer matrix of the nanocomposite, carbon nanotubes form ring-like structures. Their radius depends heavily on the volume content of the nanofiller. Therefore, the structural reinforcing element of polymer/carbon nanotube nanocomposites can be considered as ring-like formations of carbon nanotubes coated with an interfacial layer. Their structure and properties differ from the characteristics of the bulk polymer matrix.According to this definition, the effective radius of the ring-like formations increases by the thickness of the interfacial layer. In turn, the level of interfacial adhesion between the polymer matrix and the nanofiller is uniquely determined by the radius of the specified carbon nanotube formations. For the considered nanocomposites, the elastomeric matrix has a higher degree of reinforcement compared to the glassy matrix, due to the thicker interfacial layer. It was shown that the ring-like nanotube formations could be successfully modelled as a structural analogue of macromolecular coils of branched polymers. This makes it possible to assess the effective (true) level of anisotropy of this nanofiller in the polymer matrixof the nanocomposite. When the nanofiller content is constant, this level, characterised by the aspect ratio of the nanotubes, uniquely determines the degree of reinforcement of the nanocomposites