Исследование взаимодействия углекислого газа с модифицированными функциональными группами нанотрубок

Theoretical study of the possibility of interaction of one of the common substances in nature, carbon dioxide, with modified functional carboxyl and amine groups of carbon nanotubes and boroncarbon nanotubes of BC5 type was carried out. The results of interaction were analyzed and a comparative analysis of the efficiency of sorption interaction of the nanosystem with the carbon dioxide molecule was carried out. Recommendations for the further use of the results as a basis for the creation of a highly sensitive sensor device of a new generation for the detection of microcollections of substances are given.

This article is devoted to the study of the carbon dioxide adsorption process. The relevance of using carbon nanotubes for adsorbing carbon dioxide from industrial emissions is that carbon nanotubes have a high surface area and can effectively interact with carbon dioxide molecules. In addition, they have high mechanical strength and chemical resistance, which makes them attractive for industrial use. Carbon nanotubes have the potential to reduce carbon dioxide emissions and reduce the negative impact on the environment. Using carbon nanotubes in the industry can help reduce greenhouse gas emissions and the environmental impact of burning fossil fuels. Purpose. The work aimed to study the prospects of using carbon nanomaterials to purify industrial emissions from carbon dioxide in a fluidized state. The scientific novelty of the topic "Dynamics of carbon dioxide adsorption by carbon nanotubes" is the study of the influence of temperature and gas velocity on the initial curves of CO2 adsorption dynamics in the fluidized state.

With large scale production of gas from shale resources, large volumes of pore space have been vacated. Therefore, there is a large capacity for storage of carbon dioxide in these resources. Furthermore, due to the higher affinity of the organic matter to carbon dioxide compared to methane, injection of carbon dioxide can replace the adsorbed methane and therefore, enhances the recovery of natural gas. The objective for this work is to investigate the sorption (adsorption of carbon dioxide and desorption of methane) in carbon-based organic channels using Molecular Dynamics (MD) simulations. In this study, adsorption isotherms of methane and carbon dioxide are compared by performing grand canonical Monte Carlo (GCMC) simulations in identical setups of carbon channels. Excess and absolute adsorption isotherms of these gases are plotted and compared. Furthermore, the surface selectivity of carbon dioxide over methane is computed to determine the competitive adsorption of these two gases. To simulate the displacement process, MD simulations of displacement of methane molecules with carbon dioxide molecules in presence and absence of pressure gradients are performed. The results are compared for different values of gas pressures and pressure gradients. According to the results, adsorption capability of carbon dioxide is found to be higher than that of methane under the same pressure and temperature. The selectivity values of carbon dioxide over methane is found to be higher than the ones for pressure range of 100 to 200 atm, which shows that carbon dioxide molecules have higher affinity to the surface compared with methane. It is also found that carbon dioxide molecules replace adsorbed methane molecules due to their higher affinity to the surface. Concentration of methane sharply decreases as carbon dioxide molecules are introduced in the channel. The results show that the amount of carbon dioxide storage and methane production rate increases as injection pressure increases. The results in this study can impact on the research and development of new tools for both candidate selection (selection of the sites for carbon dioxide storage) and development of predictive models for estimating of the amount of carbon dioxide intake.

Cancer is a disease that causes many deaths globally. Cancer treatments have side effects that can danger the human body. Carbon nanotube (CNT) becomes drug (anti-cancer) delivery towards cancer cells that have been targeted. Yet, CNT tends to aggregate. It could be overcome by functionalization (modification) of CNT using Cetyltrimethyl Ammonium Bromide (CTAB). The variations we use were CNT-CTAB with a dose of CNT 100 mg and CTAB varied between 80, 90, 100, 110, and 120 mg. There were several stages of CNT modification process: dispersion, filtration, washing, and drying. The optimum condition obtained was on CNT-110 mg CTAB because it could be dispersed up to 70 hours better than pure CNT, Zeta Potential (ZP) ≥16 mV, and absorbance Uv-vis 1.05. Both the ZP value and the absorbance of Uv-vis showed the CNT dispersion modified to be better than the pure CNT. Furthermore, SEM-EDX did not produce structural damage to CNT modified surfaces, the percentage of the mass of Oxygen (O) elements as characteristic of increased hydrophilic properties, and Ni elements as toxic impurities become reduced. FTIR spectrum results showed the highest intensity occurred at CTAB CNT-110mg at 1221 m-1. This strong C-N vibration interaction suggests that CNTs CNT modification become readily dispersed in water.Cancer is a disease that causes many deaths globally. Cancer treatments have side effects that can danger the human body. Carbon nanotube (CNT) becomes drug (anti-cancer) delivery towards cancer cells that have been targeted. Yet, CNT tends to aggregate. It could be overcome by functionalization (modification) of CNT using Cetyltrimethyl Ammonium Bromide (CTAB). The variations we use were CNT-CTAB with a dose of CNT 100 mg and CTAB varied between 80, 90, 100, 110, and 120 mg. There were several stages of CNT modification process: dispersion, filtration, washing, and drying. The optimum condition obtained was on CNT-110 mg CTAB because it could be dispersed up to 70 hours better than pure CNT, Zeta Potential (ZP) ≥16 mV, and absorbance Uv-vis 1.05. Both the ZP value and the absorbance of Uv-vis showed the CNT dispersion modified to be better than the pure CNT. Furthermore, SEM-EDX did not produce structural damage to CNT modified surfaces, the percentage of the mass of Oxygen (O) elements as characteristic...

Simulation of the interaction of methane, carbon dioxide and coal

We have investigated the ability of two modular phyllosilicates (palygorskite and sepiolite) to store CO2 molecules inside their structural channels by means of classical molecular dynamics. Several models containing an increasing supercritical-CO2/H2O ratio into the phyllosilicate channels have been built and the structural and dynamic properties of carbon dioxide and water molecules investigated in detail. We found that both clay minerals can achieve this goal, with sepiolite being able to store more carbon dioxide molecules (and more stably) than palygorskite, due to the larger channels of the former. Interestingly, with the increase of CO2 molecules inside the minerals, the diffusivity of both water and carbon dioxide drastically decreases and carbon dioxide molecules tend to arrange themselves in an ordered pattern.

Recent technological advances like horizontal drilling and hydraulic fracturing have made recovery of gas possible from the ultra low permeable shale plays in the United States. However, recoveries from these gas shales still tend to be in the range of single digits. It is believed that more than 80% of the generated hydrocarbons still remain in these tight formations. In order to increase the recovery from these tight shale plays, an enhanced recovery procedure using supercritical carbon dioxide as the injection fluid is recommended in this paper. In the current research, molecular dynamics simulations (MDS) have been performed on the kerogen-methane-carbon dioxide system to understand the absorption-adsorption-desorption phenomena of the super critical carbon dioxide fluid. Previous studies have confirmed that the kerogen has a tendency to adsorb and absorb the hydrocarbons. In the current work, the type II kerogen model was chosen and annealed with the methane molecules. The Nose-Hoover style non-Hamiltonian equations of motion were used in a molecular simulator to generate positions and velocities sampled from the canonical (nvt) and isothermal-isobaric (npt) ensembles. This updates the position and velocity for atoms in the group each time step during the simulations. The pairwise distribution function and density of the mixture were calculated at the end of the simulations in order to validate the model with the experimental observations. The subsequent simulations with the carbon dioxide molecules in the periodic boundary conditions reveal that the carbon dioxide can sweep the absorbed methane from the kerogen matrix in the shales. The interactions at the interface between the carbon dioxide and the methane rich kerogen matrix are studied. These replicate the interactions at the fracture surface in the process of using super critical carbon dioxide as the fracturing fluid for enhanced gas recovery. Compared to methane, the carbon dioxide molecule has higher affinity to be adsorbed and eventually absorbed in the kerogen matrix because of its polar nature and linear shape. This allows the carbon dioxide to replace methane in the kerogen, thereby, sequestrating itself in the kerogen rich shale formations. Adsorption and absorption of the carbon dioxide in turn cause desorption of the methane from the kerogen, which aids in the gas recovery from such gas rich shales as the Marcellus Shale in the United States.

The Hybrid process of preozonation and CNTs modification on hollow fiber membrane for fouling control

This study investigates the elastic scattering of electrons and positrons by carbon dioxide (CO2) molecules over a wide energy range from 1 eV to 1 KeV. We have computed differential and integral elastic cross-sections (DCS and ICS) using partial wave analysis and compared the theoretical results with available experimental data. Our findings show a strong correlation with experimental results, particularly at mid to high-energy ranges, validating the employed theoretical frameworks. Additionally, the Sherman function was examined to explore spin polarisation effects during scattering events. This research provides crucial insights for applications in atmospheric physics, materials science, and molecular scattering processes, demonstrating its direct relevance to real-world problems and paving the way for further investigation into particle-molecule interactions.

The present article intended to study the influence of post-synthetic modification with ethylenediamine (en, diamine) and diethylenetriamine (deta, triamine) within the coordinatively unsaturated sites (CUSs) of HKUST-1 on carbon dioxide and hydrogen storage. The as-sythesized adsorbent was solvent-exchanged and subsequently post-synthetically modified with di-/triamines as sources of amine-based sorption sites due to the increased CO2 storage capacity. It is known that carbon dioxide molecules have a high affinity for amine groups, and moreover, the volume of amine molecules itself reduces the free pore volume in HKUST-1, which is the driving force for increasing the hydrogen storage capacity. Different concentrations of amines were used for modification of HKUST-1, through which materials with different molar ratios of HKUST-1 to amine: 1:0.05; 1:0.1; 1:0.25; 1:0.5; 1:0.75; 1:1; 1:1.5 were synthesized. Adsorption measurements of carbon dioxide at 0 °C up to 1 bar have shown that the compounds can adsorb large amounts of carbon dioxide. In general, deta-modified samples showed higher adsorbed amounts of CO2 compared to en-modified materials, which can be explained by the higher number of amine groups within the deta molecule. With an increasing molar ratio of amines, there was a decrease in wt.% CO2. The maximum storage capacity of CO2 was 22.3 wt.% for HKUST-1: en/1:0.1 and 33.1 wt.% for HKUST-1: deta/1:0.05 at 0 °C and 1 bar. Hydrogen adsorption measurements showed the same trend as carbon dioxide, with the maximum H2 adsorbed amounts being 1.82 wt.% for HKUST-1: en/1:0.1 and 2.28 wt.% for HKUST-1: deta/1:0.05 at − 196 °C and 1 bar.

In this work, the tribological properties of MoS2 films were investigated in air, vacuum and carbon dioxide environments by means of experiments and First-principles calculations. The results showed that the MoS2 film had the lowest and more stable coefficient of friction in carbon dioxide atmosphere than that in other environments. The MoS2 film usually loses some S atoms to produce S-vacancy defects during sputtering deposition, which can be filled by carbon dioxide molecules in a way of chemisorption. The strong repulsive force always existed at the interfaces of MoS2 adsorbed with carbon dioxide molecules, which was responsible for the low friction coefficient of MoS2 films in carbon dioxide. In the future, the MoS2 film is likely to be widely used on Mars that is well known for its CO2-rich atmosphere.

The formation of the cyclic carbon trioxide isomer, CO3(X 1A1), in carbon-dioxide-rich extraterrestrial ices and in the atmospheres of Earth and Mars were investigated experimentally and theoretically. Carbon dioxide ices were deposited at 10 K onto a silver (111) single crystal and irradiated with 5 keV electrons. Upon completion of the electron bombardment, the samples were kept at 10 K and were then annealed to 293 K to release the reactants and newly formed molecules into the gas phase. The experiment was monitored via a Fourier transform infrared spectrometer in absorption-reflection-absorption (solid state) and through a quadruple mass spectrometer (gas phase) on-line and in situ. Our investigations indicate that the interaction of an electron with a carbon dioxide molecule is dictated by a carbon–oxygen bond cleavage to form electronically excited (1D) and/or ground state (3P) oxygen atoms plus a carbon monoxide molecule. About 2% of the oxygen atoms react with carbon dioxide molecules to form the C2v symmetric, cyclic CO3 structure via addition to the carbon–oxygen double bond of the carbon dioxide species; neither the Cs nor the D3h symmetric isomers of carbon trioxide were detected. Since the addition of O(1D) involves a barrier of a 4–8 kJ mol−1 and the reaction of O(3P) with carbon dioxide to form the carbon trioxide molecule via triplet-singlet intersystem crossing is endoergic by 2 kJ mol−1, the oxygen reactant(s) must have excess kinetic energy (suprathermal oxygen atoms which are not in thermal equilibrium with the surrounding 10 K matrix). A second reaction pathway of the oxygen atoms involves the formation of ozone via molecular oxygen. After the irradiation, the carbon dioxide matrix still stores ground state oxygen atoms; these species diffuse even at 10 K and form additional ozone molecules. Summarized, our investigations show that the cyclic carbon trioxide isomer, CO3(X 1A1), can be formed in low temperature carbon dioxide matrix via addition of suprathermal oxygen atoms to carbon dioxide. In the solid state, CO3(X 1A1) is being stabilized by phonon interactions. In the gas phase, however, the initially formed C2v structure is rovibrationally excited and can ring-open to the D3h isomer which in turn rearranges back to the C2v structure and then loses an oxygen atom to ‘recycle’ carbon dioxide. This process might be of fundamental importance to account for an 18O enrichment in carbon dioxide in the atmospheres of Earth and Mars.

ABSTRACTNanocomposites of functionalized carbon nanotubes (CNTsf) used as a reinforcement agent, and a polyurethane (PU), as a polymeric matrix were synthesized via in situ polymerization. Carbon nanotubes (CNTs) were chemically functionalized using four different chemical treatments to obtain (1) oxidized CNTs (CNTsOH, COOH), (2) CNTs containing aliphatic amine groups (CNTset diam), (3) CNTs attached to an aromatic amine group (CNTs4AB), and (4) CNTs containing a combination of aromatic amine, hydroxyl, and carboxyl functional groups (CNTs4AB, OH, COOH). The nanocomposites (prepared using 0.25, 0.5 or 1.0 wt % CNTsf) were synthesized by two processes: (1) one‐step using a PU made from PCL‐diol (α‐ω‐telechelic polyester diol) obtained by biocatalysis from ε‐caprolactone (ε‐CL) and diethylene glycol (DEG) and 4,4′‐methylenebis (cyclohexyl isocyanate) (H12MDI) in stoichiometric amounts, (2) two‐step process (chain extended PU) using hexamethylene diamine (HMDA). Depending on the chemical route used to synthesized the nanocomposites, CNTsf form, in some cases, covalent bonds and hydrogen bonding with the soft and/or hard segments of the PU matrix. Also, the presence of CNTsf improves the thermal stability of the nanocomposites and some of their mechanical properties, compared to the pure PU properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47319.

Luminol exhibits electrochemical redox activity when electropolymerized on various substrates, and has been used for electrocatalysis and biosensors [1, 2]. This electrochemical behavior is due to the presence of different amine functional groups within the polymer structure. Recent studies have shown that introducing amine groups on a carbon surface improves the charge storage capacity and the conductivity of the obtained material [3]. Our work aims to leverage the electrochemical properties of polyluminol (Plum) for electrochemical capacitors (ECs). Firstly, the Plum was synthesized using a chemical approach and characterized using spectroscopic methods and electrochemical analyses. Secondly, the polymer was deposited on carbon nanotubes (CNT) to enhance the charge storage capacity for ECs. The chemical composition of the polymer was found to be a mixture of benzoid and quinoid segments, bonded via secondary (NH) or tertiary amine (=N-) groups, respectively. Such functionalities facilitated chemical, thermal, and electrochemical stability of the polymer. The composite electrode material was obtained by in-situ chemical polymerization of Plum on CNT. Morphological analyses of CNT confirmed the increase of the Plum thickness on CNT with polymerization time, reaching a saturation point of 6.5 nm. In addition, a 4x increase of charge storage capacity with good electrode stability was observed compared to bare CNT over a potential window of 1.2 V as seen in figure 1. Study of the redox reaction kinetics revealed a mostly capacitive contribution of the polymer on CNT. This work showed the successful surface modification and engineering of CNT using a simple and effective fabrication method, which is suitable for large-scale fabrication of composite electrode materials for ECs. G.-F. Zhang and H.-Y. Chen, Analytica Chimica Acta, 419, 25 (2000).A. Sassolas, L. J. Blum and B. D. Leca-Bouvier, Sensors and Actuators B: Chemical, 139, 214 (2009).N. Phattharasupakun, J. Wutthiprom, P. Suktha, N. Ma and M. Sawangphruk, Journal of The Electrochemical Society, 165, A609 (2018). Figure 1

Carbon dioxide (CO2) is the most significant greenhouse gas, contributing 44% of global warming using coal combustion for electricity generation. The major goal is to reduce carbon dioxide emissions by using the carbon dioxide capture and storage (CCS) technique. Among various techniques, amine-based post-combustion carbon dioxide capture plays a critical role in CCS technology. Monoethanolamine (MEA) acts as a benchmarking solvent in the CCS process owing to its high absorption capacity, lower cost and high rate of reaction. The present investigation used 30 wt% MEA and animised flue gas (15 vol% carbon dioxide and resting nitrogen (N2) gas) at 0.5 pound/square inch (3.45 kPa) inlet pressure for carbon dioxide absorption followed by 1 h solvent regeneration (direct and indirect heating). Furthermore, measurements of physico-chemical properties such as pH, carbon dioxide loading, density, viscosity, alkalinity and surface tension and Fourier transform infrared (FTIR) spectroscopic analysis of unloaded, carbon dioxide-loaded and regenerated samples were carried out. During carbon dioxide absorption, a rich loading of 7.775 mol/kg was obtained, whereas after regeneration, lean loadings of 3.099 and 3.937 mol/kg were achieved. FTIR analysis of the regenerated sample reconfirmed carbamate and bicarbonate presence, indicating that the sample required further regeneration. An increase in density, viscosity and surface tension was observed during carbon dioxide loading due to stronger intermolecular forces between the solvent and carbon dioxide molecules, and a decrease was observed during solvent regeneration due to carbon dioxide stripping.