Triple Carbon Research Articles

Carbon Nanotubes and its Application in Nanotechnology

Carbon nanotubes often refer to single-wall carbon nanotubes (SWCNTs) with diameters in the range of a nanometer. Single-wall carbon nanotubes are one of the allotropes of carbon, intermediate between fullerene cages and flat graphene. Carbon nanotubes also often refer to multi-wall carbon nanotubes(MWCNTs), consisting of nested single-wall carbon nanotubes, weakly bound together by van der Waals interactions in a tree ring-like structure. If not identical, these tubes are very similar to long straight and parallel carbon layers, cylindrically arranged around a hollow tube. Multi-wall carbon nanotubes are also sometimes used to refer to double and triple wall carbon nanotubes. Carbon nanotubes can also refer to tubes with an undetermined carbon wall structure and diameters less than 100 nanometers. While nanotubes of other compositions exist, most research has been focused on the carbon ones. The length of a carbon nanotube produced by common production methods is typically much larger than its diameter. Thus, for many purposes, end effects are neglected and the length of carbon nanotubes is assumed infinite. Carbon nanotubes can exhibit remarkable unique properties. These include electrical conductivity, while others are semiconductors. They also have exceptional tensile strengthand thermal conductivity, because of their nanostructure and strength of the bonds between carbon atoms. In addition, they can be chemically modified. Thus, due to their variable, unique properties, carbon nanotubes have found applications in many realms such as electronics, optics, composite materials nanotechnology, and other applications of materials science. In addition, carbon nanotubes can be integrated into other molecules to form novel structures with unique properties, different from the individual reactants. These unique products have also found application in many realms of nanotechnology

Absorption and fluorescence spectra of conjugated polymers poly(propylene oxide)–poly(phenylene ethynylene) interpreted by Franck–Condon simulation

AbstractAbsorption and fluorescence spectra of the poly(propyleneoxide)–poly(phenylene ethynylene) with long polymer chains in the experiment are investigated by the Franck–Condon simulation with small polymer chains in the theory. Electronic calculations with time‐dependent density functional (TDDFT) indicate that vibronic spectra come from S1(ππ*) excitation and de‐excitation. Good agreement between Franck–Condon simulated and experimentally measured absorption and fluorescence spectra in three kinds of solutions is achieved. However, vibronic spectral analysis reveals that vibronic motion mechanisms are quite different for simulated absorption and fluorescence spectra. For absorption spectra, vibronic spectra are dominated by one most active mode localized in triple bond carbon–carbon stretch motion on backbone of the poly (phenylene ethynylene), and simulated absorption spectra indicate that the long chains can be as stable as short chains on the electronic ground state in comparison with experimental spectra in all solvents. In the case of fluorescence spectra, this most active mode is spitting into several equally active modes with very close values in vibrational frequencies, and thus, the spitting modes and mode couplings among those spitting dominate vibronic spectra. Simulated fluorescence spectra indicate that the only short chains are stable on the electronic excited state in comparison with experimental spectra in all solvents. Nevertheless, the present simulation concludes that both absorption and fluorescence spectra are induced mostly by the active normal mode in triple bond carbon–carbon stretch motion on backbone of poly(phenylene ethynylene). The present work provides physical insight for analyzing observed vibronic spectra of similar conjugated polymers and for designing novel optoelectronic materials.

Mid–Late Ordovician tetradiid–calcimicrobial–cement reef: A new, peculiar reef-building consortium recording global cooling

Skeletal–microbial–cement reefs are a triple hybrid carbonate that mainly formed during the Pennsylvanian to Mid-Triassic, when a marked increase in microbial carbonate formation coincided with extensive precipitation of crystalline crusts on the seafloor. We report a new type of reef-building association from Middle–Upper Ordovician strata of western North China, in which erect thin tubes of tetradiids (coralomorph) are encrusted by the calcimicrobes Renalcis and Angusticellularia and then by a large amount of early marine cement that is presumably high-Mg calcite or aragonite in composition. The resulting meter-scale mound is embedded within intraclastic–bioclastic grainstone, implying high-energy shallow-marine conditions. The thin tetradiid tubes, which would have been unable to physically withstand strong waves and currents, are interpreted to have been consolidated by encrusting calcimicrobes and then by extensive early marine cementation. Tetradiid-bearing reefs have generally been reported from muddy successions; the results of the present study suggest that consolidators were important in reef-building in high-energy environments during the later Ordovician. Considering also the coeval bivalve–sponge–microbial–cement reef reported from the same area and a sponge–microbial–cement reef from Arctic Canada, early marine cementation appears to have been at least locally important in the late Ordovician, similar to the Pennsylvanian through the Mid-Triassic. These triple hybrid carbonates may have formed by a combination of: (1) emergence of newly evolved skeletal reef-builders during the Great Ordovician Biodiversification Event; (2) development of CO2-concentrating mechanisms in calcimicrobes induced by a decrease in atmospheric CO2; and (3) an increase in the calcium saturation state in seawater resulting in extensive abiotic cementation as well as calcification of microbes. All of these factors might have been induced by global cooling throughout the Mid–Late Ordovician.

A novel semi-analytical model for oil-water two-phase flow of a fractured vertical well in triple media carbonate reservoir

A novel semi-analytical model for oil-water two-phase flow of a fractured vertical well in triple media carbonate reservoir

Comparative Study of Carbon Force Fields for the Simulation of Carbon Onions

We evaluate the performance of ten common carbon force fields for the interaction energies in double and triple layered carbon onions. In particular, we consider the C20@C60, C20@C80, C20@C180, C80@C240, C60@C240 and C240@C540 double-layer carbon onions and C60@C240@C540 and C80@C240@C540 triple-layered carbon onions. We consider the following carbon force fields: Tersoff, REBO-II, AIREBO, AIREBO-M, screened versions of Tersoff and REBO-II, LCBOP-I, 2015 and 2020 versions of ReaxFF, and the machine-learning GAP force field. We show that the ReaxFF force fields give the best performance for the interaction energies of the cabon onions relative to density functional theory interaction energies obtained at the PBE0-D3/def2-TZVP level of theory. We proceed to use the ReaxFF-15 force field to explore the interaction energies in a giant ten-layered carbon onion with a C60 core and show that the interaction energy between the outer layer and the inner layers increases linearly with the number of layers in the carbon onion (with a squared correlation coefficient of R2 = 0.9996). This linear increase in the stabilization energy with each consecutive layer may have important thermodynamic consequences for describing the formation and growth of large carbon onions.

A PROSPECTIVE RANDOMIZED STUDY OF COMPARISON OF PROPHYLACTIC KETAMINE, CLONIDINE AND TRAMODOL FOR THE CONTROL OF SHIVERING UNDER NEURAXIALANAESTHESIA

Background: Thermoregulatory system coordinates defenses against environmental temperature to maintain internal core temperature within a narrow range, thus optimizing normal body function and homeostasis in humans. Anaesthetic induced thermoregulatory impairment and hence hypothermia in cold environments. Shivering is an important complication of hypothermia. Shivering is an involuntary, oscillatory muscular activity that augments metabolic heat production upto 600% above basal level to increase temperature. It is associated with substantial adrenergic activation, discomfort and can double or even triple oxygen consumption and carbon dioxide production. Potent anti-shivering properties have been attributed to numerous drugs including biogenic monoamines, cholinomimetics, cations, endogenous peptides and possibly N-methyl-D- aspartate (NMDA) receptor antagonists like ketamine, tramadol and clonidine. Aim: To evaluate the effectiveness of prophylactic use of intravenous ketamine, clonidine and tramadol in control of shivering and to note any side-effects of the drugs used. Methods: A total number of 120 ASA I and 2 patients of either sex belonging to age group 18-60 years posted for Lower Abdomen and Lower Limb surgeries under subarachnoid block were divided into four groups of 30 each. Group P (control group): Patients received 10mL of normal saline IV as placebo. Group K: Patients received Inj. Ketamine 0.5mg/kg BW IV diluted to 10ml in Normal Saline. Group C: Patients received Inj. Clonidine 75mcg IV diluted to 10ml in Normal Saline. Group T: patients received Inj. Tramadol 0.5mg/kg BW IV diluted to 10ml in normal saline. Results: We conclude that giving Ketamine 0.5mg/kg,Clonidine 75mcg or tramadol 0.5mg/kg i.v. prophylactically just before subarachnoid block significantly decreased the incidence of shivering without causing any major side effects. Conclusion: Ketamine, Tramadol or Clonidine decrease shivering during spinal anesthesia.

Poly(methylvinylsiloxane)-Based High Internal Phase Emulsion-Templated Materials (polyHIPEs)-Preparation, Incorporation of Palladium, and Catalytic Properties.

Poly(methylvinylsiloxane) (V3 polymer) obtained by kinetically controlled anionic ring-opening polymerization of 1,3,5-trimethyl-1,3,5-trivinylcyclotrisiloxane was cross-linked with various amounts of 1,3,5,7-tetramethylcyclotetrasiloxane (D4H) in w/o high internal phase emulsions (HIPEs). PolyHIPEs thus prepared differed in the polymer cross-linking degree, which affected their porous morphology and total porosity. The obtained V3 polymer-based polyHIPEs were applied as matrices for the incorporation of Pd from the Pd(OAc)2 solution in tetrahydrofuran. This process involved the conversion of Si–H groups remaining in the polymer networks and resulted in the formation of crystalline, metallic Pd in the systems. Mean sizes of the generated Pd crystallites were lower in polyHIPEs of higher than in those of lower polymer cross-linking degrees and porosities (∼5 nm vs ∼8 nm, respectively). The Pd-containing polyHIPEs showed activity in catalytic hydrogenation of the triple carbon–carbon bond in phenylacetylene giving the unsaturated product, styrene with a selectivity of ca. 80%. To the best of our knowledge, this is the first work devoted to polysiloxane-based polyHIPEs with dispersed metallic particles.

Highly Sensitive Electrochemical Sensor for the Detection of Chloramphenicol Based on Biomass Derived Porous Carbon

In this study, the method for detection of chloramphenicol was investigated by electrochemical sensor; the sensor was constructed by biomass derived porous carbon. At first, porous carbon doped with hetroatoms (nitrogen, sulfur, phosphorus) was synthesized based on the use of pyrolysis and high temperature carbonization methods. Elaeagnusangustifolia L. gum was used as the carbon source in the facile template-free process. The biomass derived porous carbon was then used as the active electrode material for antibiotic sensing. The chemically modified electrodes properties were studied with the cyclic voltammetry and differential pulse voltammetry methods. The effects of the scan rate, accumulation time and pH, were carefully considered. Comparison with other working electrodes at the optimized conditions indicated that the N, S, P triple doped porous carbon modified glassy carbon electrode appeared a well-defined reduction peak towards chloramphenicol. The linear concentration response of chloramphenicol ranged from 1 to 40 μM (R=0.9903) and 50 to 500 μM (R=0.9923), and a low detection limit of 0.01 μM (S/N=3). Furthermore, the constructed novel electrochemical sensor was used for detection of chloramphenicol in real samples and achieved satisfactory recovers.

Dynamic analysis of oil‐water two‐phase flow for a multiple‐fractured horizontal well with multiple finite‐conductivity fractures in triple media carbonate reservoir

AbstractCarbonate reservoir is one of the important reservoir in the world. Because of the characteristics of carbonate reservoir, horizontal well and acid fracturing have become a key technology for efficiently developing carbonate reservoir. Establishing corresponding mathematical models and analyzing transient pressure behaviors of this type of well‐reservoir configuration can provide a better understanding of fluid flow patterns in formation as well as estimations of important parameters. A mathematical model for a oil‐water two‐phase flow multiple‐fractured horizontal well with multiple finite‐conductivity fractures in triple media carbonate reservoir by conceptualizing vugs as spherical shapes is presented in this article. A semi‐analytical solution is obtained in the Laplace domain by using source function theory, Laplace transformation, and superposition principle. Analysis of transient pressure responses indicates that nine characteristic flow periods of multiple‐fractured horizontal wells with multiple finite‐conductivity fractures in triple media carbonate reservoir can be identified. Parametric analysis shows that water saturation of matrix, vug and fracture system and acid fracture, fracture half‐length, fracture number, fracture spacing and acid fracture conductivity can significantly influence the transient pressure responses of multiple‐fractured horizontal wells with multiple finite‐conductivity fractures in triple media carbonate reservoir. The model presented in this article can be applied to obtain important parameters pertinent to reservoir or fracture by type curve matching, and it can also provide useful information for optimizing fracture parameters.

Polarization Effect on Regioselectivity of Pd‐Catalyzed Cyclization of 2‐Alkynylbenzaldehydes

We report a study on the relationship between the polarization of C≡C bond in a series of 2‐alkynylbenzaldehydes and the regioselectivity of their Pd‐catalyzed annulation reactions. The electrophilic and nucleophilic character of the triple bond carbon atoms was examined using 13C and HMBC NMR experiments. The direction of polarization is determined only by the formyl group and its position on an aromatic ring. On the other hand, the strength of the polarization expressed through chemical shift difference Δδ of acetylenic carbon atoms is a result of electron‐withdrawing or electron‐donating ability of the other substituent. Out of two possible regioisomers, the Pd‐catalyzed cyclization reactions of 2‐alkynylbenzaldehydes that were studied predominantly afforded 1H‐isochromenes suggesting that the polarization of a triple bond is one of the contributing factors in the regioselectivity of this process.

The Diels–Alder Reaction for the Synthesis of Polycyclic Aromatic Compounds

Polycyclic aromatic compounds (PACs) represent a class of molecules consisting of two or more condensed aromatic rings. They are currently of great interest as potential semiconducting materials for organic field‐effect transistors, light‐emitting diodes, and solar panels. Substituted PACs are not always readily available and may require complicated multi‐step synthetic procedures to be obtained. One of the promising methods of the synthesis of functionalized PACs is the assembly of polycyclic backbones from substituted building blocks via cycloaddition reactions, in particular, the Diels–Alder reaction. In this minireview we aimed to cover the recent progress in the application of the Diels–Alder reaction in PACs synthesis with the emphasis on the structures of dienophiles. While quinones and arynes still act most frequently as the dienophilic components, other dienophiles with activated double and triple carbon–carbon bonds attract attention due to the ability of insertion of functional groups into polycyclic structures. In the recent decade variants of Dehydro Diels–Alder reaction, especially HexaDehydro Diels–Alder reaction (HDDA) attract much attention leading to the formation of polycyclic structures in a single step. The present review covers mostly papers published during the past decade; older works are referenced only when it is necessary for the understanding of the results discussed.

Triple stimuli-responsive ZnO quantum dots-conjugated hollow mesoporous carbon nanoplatform for NIR-induced dual model antitumor therapy

Aiming at the inefficiency and toxicity in traditional antitumor therapy, a novel multifunctional nanoplatform was constructed based on hollow mesoporous carbon (HMC) to achieve triple stimuli response and dual model antitumor therapy via chemo-photothermal synergistic effect. HMC was used as an ideal nanovehicle with a high drug loading efficiency as well as a near-infrared (NIR) photothermal conversion agent for photothermal therapy. Acid-dissoluble, luminescent ZnO quantum dots (QDs) were used as the proper sealing agents for the mesopores of HMC, conjugated to HMC via disulfide linkage to prevent drug (doxorubicin, abbreviated as Dox) premature release from Dox/HMC-SS-ZnO. After cellular endocytosis, the Dox was released in a pH, GSH and NIR laser triple stimuli-responsive manner to realize accurate drug delivery. Moreover, the local hyperthermia effect induced by NIR irradiation could promote the drug release, enhance cell sensitivity to chemotherapeutic agents, and also directly kill cancer cells. As expected, Dox/HMC-SS-ZnO exhibited a high drug loading capacity of 43%, well response to triple stimuli and excellent photothermal conversion efficiency η of 29.7%. The therapeutic efficacy in 4T1 cells and multicellular tumor spheroids (MCTSs) demonstrated that Dox/HMC-SS-ZnO + NIR had satisfactory chemo-photothermal synergistic effect with a combination index (CI) of 0.532. The cell apoptosis rate of the combined treatment group was more than 95%. The biodistribution and pharmacodynamics studies showed its biosecurity to normal tissues and synergistic inhibition effect to tumor cells. These distinguished results indicated that the Dox/HMC-SS-ZnO nanoplatform is potential to realize efficient triple stimuli-responsive drug delivery and dual model chemo-photothermal synergistic antitumor therapy.

Redox behavior of novel FeOx/Pd/SiO2 catalytic nanomaterials

Novel FeOx/Pd/SiO2 materials have been first synthesized by the redox methods including reduction with H2 at ambient conditions. The method of the temperature-programmed reduction with hydrogen (TPR-H2) was applied to study the influence of preparation conditions on the reducibility of supported FeOx species and stability of the reduced moieties to oxygen. The decreased temperature of β-PdH decomposition, as well as the intensive hydrogen consumption at − 50 to 100 °C due to FeOx reduction, has proved deposition of FeOx species on the surface of Pd nanoparticles. The phase composition, particle size and morphology were characterized with XRD, SEM and TEM. The highly reducible FeOx/Pd/SiO2 materials exhibited a multiple increase in the catalytic activity, as compared to the starting Pd/SiO2 material, in the selective hydrogenation of triple and double carbon bonds with molecular H2 in hydrogenation of phenylacetylene in liquid phase at room temperature and 1 bar hydrogen pressure.

Determination of the triple oxygen and carbon isotopic composition of CO2 from atomic ion fragments formed in the ion source of the 253 Ultra high-resolution isotope ratio mass spectrometer.

RationaleDetermination of δ17O values directly from CO2 with traditional gas source isotope ratio mass spectrometry is not possible due to isobaric interference of 13C16O16O on 12C17O16O. The methods developed so far use either chemical conversion or isotope equilibration to determine the δ17O value of CO2. In addition, δ13C measurements require correction for the interference from 12C17O16O on 13C16O16O since it is not possible to resolve the two isotopologues.MethodsWe present a technique to determine the δ17O, δ18O and δ13C values of CO2 from the fragment ions that are formed upon electron ionization in the ion source of the Thermo Scientific 253 Ultra high‐resolution isotope ratio mass spectrometer (hereafter 253 Ultra). The new technique is compared with the CO2‐O2 exchange method and the 17O‐correction algorithm for δ17O and δ13C values, respectively.ResultsThe scale contractions for δ13C and δ18O values are slightly larger for fragment ion measurements than for molecular ion measurements. The δ17O and Δ17O values of CO2 can be measured on the 17O+ fragment with an internal error that is a factor 1–2 above the counting statistics limit. The ultimate precision depends on the signal intensity and on the total time that the 17O+ beam is monitored; a precision of 14 ppm (parts per million) (standard error of the mean) was achieved in 20 hours at the University of Göttingen. The Δ17O measurements with the O‐fragment method agree with the CO2‐O2 exchange method over a range of Δ17O values of −0.3 to +0.7‰.ConclusionsIsotope measurements on atom fragment ions of CO2 can be used as an alternative method to determine the carbon and oxygen isotopic composition of CO2 without chemical processing or corrections for mass interferences.

The role of carbon bond types on the formation of solid electrolyte interphase on graphite surfaces

Solid electrolyte interphase (SEI) has been extensively investigated in advanced lithium ion batteries, especially on graphite anode surface. However, the role of the carbon bond types on the formation of solid electrolyte interphase (SEI) on graphite surface has never been compared. In this work, single, double and triple carbon bonds on a graphite anode acting as SEI templates are comparatively investigated. Sodium propionate, sodium acrylate and sodium propynate are uniformly applied onto a natural graphite surface. It is found that different carbon types exhibit remarkable difference in the electrochemical behavior of the graphite anode. The acrylate SEI template demonstrates the best film-forming properties via in-situ polymerization between the carbon double bonds producing robust SEI film and the decorated graphite anode shows much enhanced rate capability and cycling stability. Moreover, life-span of the full cell with LiFePO4 cathode is significantly prolonged. By contrast, single and triple carbon bonds shows some limitations in the SEI formation. Therefore, constructing SEI film by in-situ polymerization of carbon double bonds is an effective strategy enhancing the durability and reliability of graphite anode.

Dynamic Analysis of a Fractured Vertical Well in a Triple Media Carbonate Reservoir

Carbonate reservoir is one of the important reservoirs in the world. Because of the characteristics of carbonate reservoir, vertical well and acid fracturing have become a key technology for efficiently developing a carbonate reservoir. Establishing corresponding mathematical models and analyzing transient pressure behaviors of this type of well-reservoir configuration can provide a better understanding of fluid flow patterns in formation as well as estimations of important parameters. A mathematical model for a fractured vertical well in triple media carbonate reservoir by conceptualizing vugs as spherical shapes is presented in this article. A semi-analytical solution is obtained in the Laplace domain by using source function theory, Laplace transformation, and the superposition principle. Analysis of transient pressure responses indicates that several characteristic flow periods of fractured vertical wells in triple media carbonate reservoir can be identified. Parametric analysis shows that the fracture length can significantly influence the transient pressure responses of fractured vertical wells in triple media carbonate reservoir. The model presented in this article can be applied to obtain important parameters pertinent to reservoir or fracture by type curve matching, and it can also provide useful information for optimizing fracture parameters.

Ab initio STUDY OF POINT DEFECTS IN 2D GRAPHENE LAYER

With a hexagonal (honeycomb) network of mono-layered carbon atoms, graphene has demonstrated outstanding electronic properties. This work describes the impact of deliberately introduced single, double and triple carbon vacancies in grapheme monolayer. In addition, these carbon vacancies were then substituted with gold atoms and their influence on the electronic properties of the two-dimensional (2D) graphene layers was investigated. In this regard, a first principle calculation was performed to examine electronic properties and formation energy of 2D graphene layer by applying density functional theory (DFT). Introduction of such defects appeared to increase the stability of the graphene sheet as confirmed by formation energy calculations. Moreover, decrease of formation energy was noticed to be significant with an increase in the number of defects. Band structure calculations described the shifting of localized states from valance to conduction bands which caused the transformation of semiconducting behavior into metallic one on the filling of carbon vacancies by gold atoms. Comparing this behavior with that of partial density of states (PDOS) it was noted that a lot of states existed in the valance band in the case of C-vacancies yielding charge free region around the vacancy. On the other hand, filling of C-vacancies by gold generated a large number of energy states in the conduction band illustrating the accumulation of charges near gold atom. Width of the peak across the Fermi level indicated the accumulative energy of electron to be almost 0.15[Formula: see text]eV. These calculated DOS and PDOS demonstrated metallic like behavior of the graphene monolayer with typical defect states.

Triple Hierarchical Porous Carbon Spheres as Effective Cathodes for Li–O2 Batteries

This paper presents the synthesis and characterization of triple hierarchical porous carbon spheres as cathodes in lithium–oxygen batteries. The porous carbon cathode exhibits a higher discharge capacity and average discharge potential compared to a typical carbon black cathode. This superior electrochemical result can be attributed to the triple hierarchical pores of the cathode: micropores that act as channels for oxygen to flow without interruption by the accumulated discharge product, abundant mesopores that shape the size of the discharge product and transport the electrolyte, and macropores that easily accommodate the accumulation of discharge product. To further promote Li2O2 formation/decomposition, the cathode can be decorated with a Ru catalyst, which strongly influences the oxygen evolution reaction performance. Conspicuously, triple hierarchical porous carbon spheres exhibit a homogeneous distribution of the Ru catalyst and thus provide an appropriate architecture. The synergistic effect from the unique structure and catalytic competence of Ru increases the capacity and rate capability with lower over-potential, and facilitates the formation of Li2O2. This can be decomposed at a low potential during recharge and thus contributes to the very high energy efficiency.

CO2 absorption and desorption characteristics of MgO-based absorbent promoted by triple eutectic alkali carbonate.

Carbon capture and sequestration is emerging as a promising technology to mitigate the greenhouse effect by reducing CO2 emissions. Of a number of metal oxides applied as CO2 absorbents, MgO is a potential material that can operate in a relatively low elevated temperature range (200-500 °C), namely, intermediate-temperatures. In the present research, we investigated the characteristics of CO2 absorption and desorption on MgO-based absorbents promoted by molten alkali metal carbonate that has a melting point of 397 °C (eutectic molar ratio of Li2CO3 : Na2CO3 : K2CO3 = 0.435 : 0.315 : 0.250). These absorbents absorb CO2 in two steps with the first step being very fast and large in capacity in comparison with other related absorbents in the literature and the second step being much slower than the first one. The overall capacity can be as large as 77% MgO conversion, much larger than other carbonate-promoted MgO absorbents in the literature. The fast first step of CO2 absorption is associated with the reaction of highly basic sites on the MgO surface formed through the interaction between the carbonates and MgO upon pre-treatment. Detailed analyses via in situ XRD revealed that MgCO3 and a new phase, probably a double carbonate between Mg and alkali ions, are formed as the carbonation products. A detailed mechanism is proposed based on the experimental data, which highlights the unique properties of the molten alkali carbonate as a dissolution medium for CO2 and MgO and even the product MgCO3.

Theoretical analysis of chirality and scale effects on critical bucklingload of zigzag triple walled carbon nanotubes under axial compression embedded in polymeric matrix

Using the non-local elasticity theory, Timoshenko beam model is developed to study the non- local buckling of Triple-walled carbon nanotubes (TWCNTs) embedded in an elastic medium under axial compression. The chirality and small scale effects are considered. The effects of the surrounding elastic medium based on a Winkler model and van der Waals\'(vdW) forces between the inner and middle, also between the middle and outer nanotubes are taken into account. Considering the small-scale effects, the governing equilibrium equations are derived and the critical buckling loads under axial compression are obtained. The results show that the critical buckling load can be overestimated by the local beam model if the small-scale effect is overlooked for long nanotubes. In addition, significant dependence of the critical buckling loads on the chirality of zigzag carbon nanotube is confirmed. Furthermore, in order to estimate the impact of elastic medium on the non-local critical buckling load of TWCNTs under axial compression, the use of these findings are important in mechanical design considerations, improve and reinforcement of devices that use carbon nanotubes.