Mixture Of 2-propanol Research Articles

Enhanced performance of on-chip integrated biosensor using deep learning

A new approach for determining the concentration composition of a multi-element media using a micro-ring resonator (MRR) is proposed which allows for both electrical and thermal noise removal as well as moderately higher average accuracy. This method uses two neural networks, namely a convolutional neural network (CNN) and a deep neural network (DNN). The CNN differentiates the transmission spectrum from the noise. This spectrum is used to obtain selected features before being fed into the DNN, which determines the concentration of each chemical in the analyte. Both models are trained to work using simulated data from a silicon on-insulator ring resonator operating between the infrared wavelengths of lambda =1.46,upmu hbox{m} to lambda =1.6,upmu hbox{m} on mixtures of water, ethanol, methanol, and propanol, although the same approach can be used with other designs and substances. The CNN was trained using the MRR transmission spectra superimposed with white Gaussian noise as well as Poisson noise to mimic different noise sources, while the DNN underwent training on the extracted features. Average root-mean-square error for element concentration for the entire system is 0.0775% for a range of concentrations from 0.0357 to 75%, and the largest error had a value of 0.68% concentration.

Effect of salt-based deep eutectic solvent on vapor-liquid equilibrium for the mixture of 2-propanol and water

Salt-based deep eutectic solvents (DESs) (i.e, ethylene glycol-choline chloride-MgBr2 (1: 0.6: 0.05) and ethylene glycol-choline chloride-MgCl2 (1: 0.6: 0.05)) have been proposed in this work for the separation of the azeotrope of 2-propanol and water (H2O). Based on the newly determined experimental data for the systems (2-propanol + H2O + DESs), revised LIQUAC model was developed for describing the vapor-liquid phase equilibrium of the system (2-propanol + H2O + DESs). Comparisons of model calculated and experimental measured values proved that the model presented here provides a reliable method for correlating the vapor-liquid equilibria data. Furthermore, both the VLE experiments and the model were used to study the effect of salt-based deep eutectic solvent on vapor–liquid equilibria. It was revealed that ethylene glycol-choline chloride-MgCl2 (1: 0.6: 0.05) is more promising than ethylene glycol-choline chloride-MgBr2 (1: 0.6: 0.05) as entrainer for the separation of mixture (2-propanol + water).

Toluene and 2-propanol mixture oxidation over Mn2O3 catalysts: Study of inhibition/promotion effects by in-situ DRIFTS

Three Mn2O3 catalysts were synthetized by different methods, characterized and tested in toluene and 2-propanol (iPrOH) oxidation in single and binary component mixture. In single VOC media, the catalytic activity was strongly influenced by the specific surface area, low-temperature reducibility and active surface-oxygen species. In the binary VOCs mixture oxidation, light-off curves were shifted to lower temperatures, suggesting a promoting effect on the catalytic activity for toluene and iPrOH oxidation. The acetone production in binary mixture was also shifted to lower temperatures. The obtained results were rationalized based on the different polarity of the VOCs, the available adsorbed oxygen and the exothermic character of the VOCs combustion. These promoting effects were pointed out by in-situ DRIFTS measurements, in which the pre-adsorption of any of these two VOCs affected the adsorption/reaction of the other. For the first time, in-situ DRIFTS has been applied to elucidate the reaction mechanisms of the oxidation of toluene/2-propanol mixture on Mn2O3, which allowed to correlate the surface phenomena and the catalytic performance.

Enhanced extraction of brominated flame retardants from e-waste plastics

Acrylonitrile butadiene styrene (ABS) is a high utility engineering thermoplastic, abundantly present in waste electronic and electrical goods. The demand for this plastic resin increases continuously with rapid industrial growth across the world. During the recycling of e-waste plastics, it is a common occurrence to find brominated flame retardants, such as Tetrabromobisphenol A (TBBPA) in the plastic. These flame retardants are intentionally added to the plastics as additives. Three processes were investigated to find the optimum solvent/antisolvent combinations, process parameters for the efficient recovery of TBBPA free plastics: microwave assisted extraction (MAE), ultrasound assisted extraction (UAE), and dissolution reprecipitation (DR). Rigorous solvent screening was carried out for both TBBPA and ABS using Hansen Solubility Parameters (HSP), and their interactions with the solvents were investigated with a molecular based Conductor like Screening Model for Realistic Solvents (COSMO-RS) software platform. A 4:1 (v/v) solvent mixture of 1-propanol and heptane was found to be ideal for the solid–liquid extraction process. The optimal extraction conditions (Temperature = 110 – 130 °C, time = 60 to 70 min solid/liquid ratio of 0.025) in MAE were predicted using machine learning based Support Vector Regression (SVR) technique. MAE was found to be superior to UAE and DR processes in terms of quantity and quality of recovered plastics. The maximum extraction efficiencies for TBBPA removal were achieved with MAE, UAE, and DR processes at 95.81%, 93.92%, and 98.15%, respectively. However, the DR process had a relatively lower plastic recovery.

Thermodynamics of 2-alkanol + polar organic solvent mixtures. I. Systems with ketones, ethers or organic carbonates

The mixtures 2-propanol or 2-butanol + n-alkanone, or + acetophenone, or + linear monoether, or + cyclic ether, or + linear organic carbonate, or + propylene carbonate have been investigated using thermodynamic data, and in terms of the Flory theory, and the Kirkwood-Buff integrals. The data considered are: excess molar enthalpies (HmE), volumes, entropies, and the temperature dependence ofHmE. The enthalpy of the 2-alkanol-solvent interactions have been determined, and the different contributions to HmE discussed. It is shown that HmE values of the 2-alkanol (fixed) + n-alkanone, or + linear carbonate mixtures change in the same manner that for n-alkanone, or linear carbonate + n-alkane (fixed) systems. In contrast, HmE values of 2-alkanol (fixed) + linear monoether or + n-alkane mixtures change similarly. This set of results suggests that solvent–solvent interactions are determinant in systems with n-alkanone or linear carbonate, while interactions between alcohol molecules are determinant in mixtures with linear monoethers. According to the Flory model, orientational effects in systems with a given 2-alkanol become weaker in the sequence: linear monoether > linear organic carbonate > n-alkanone, and are stronger in solutions with a cyclic monoether than in those with cyclic diethers, and in systems with acetophenone or propylene carbonate than in the mixtures with the corresponding linear solvents. Results obtained from the Kirkwood-Buff integrals are consistent with these findings. The application of Flory model reveals that orientational effects are similar in systems with 1- or 2-alkanols, with the exception of solutions with linear monoethers, where such effects are stronger in mixtures containing 1-alkanols. For the examined systems, the formalism of the Kirkwood-Buff integrals makes no meaningful distinction between solutions with 1-alkanols or 2-alkanols.

A New Mathematical Model for the Characterization of Viscosity Variations in the Aqueous Solutions of Monoalcohols and Polyalcohols

This study aims to investigate the viscosity of binary mixtures of water with different monoalcohols and polyalcohols. The viscosity values of the mixtures of methanol, ethanol, 1-propanol, and 2-propanol were taken from a study published by Herraez and Belda (2004). The values for ethylene glycol, glycerin, and sorbitol were measured using a similar protocol. The viscosity of the mixture is expressed as a function of the molar fraction of the alcohols that ranges from 0 (pure solvent, water in this case) to 1 (pure solute). To represent the viscosity of these mixtures, a new variable, Φ, was introduced. This representation provides a function, η = f(Φ), that has an exponential nature, with which excellent correlation coefficients are achieved with only one coefficient for monoalcohols or two coefficients for polyalcohols. Additionally, the variable Φ highlights the possible critical points, where physicochemical interactions occur between the components of the mixture.

Exploitation of the enantioselectivity space of coated amylose tris(3,5-dimethylphenylcarbamate) in mixtures of 2-propanol and acetonitrile

Chiral stationary phases (CSPs) with coated amylose tris(3,5-dimethylphenylcarbamate) (ADMPC) selector have long been recognized for their excellent chiral recognition ability in liquid chromatography. The conformational versatility behind this feature is the source of their known hysteretic behavior, which has been previously observed in polar organic (PO) mode eluents containing 2-propanol (IPA). Mixtures of IPA and acetonitrile (MeCN), a typical PO mode eluent system, have not been examined in this aspect yet, even though hysteresis is promising for finding unique unexplored enantioselectivities.Not only was the hysteresis detectable on ADMPC using mixtures of IPA and MeCN, but it was the typical behavior in a diverse set of test compounds. The difference in the retention time of the same analyte under conditions which only differed in the eluent history on the column can go up to 20-fold. The assumed hindered conformational changes of the selector were reflected in retention drift at certain eluent compositions. On the two sides of the transitions, distinct, useful states of the selector were detected. A series of IPA – MeCN compositions with defined pretreatment was selected and recommended as an extension of the preliminary, first choice method screening set that used only alcohols. The incorporation of a solvent possessing substantially different characteristics enhances the potential in practical applications, while keeping the technical simplicity. Stability and robustness of the additional states of the CSP were characterized. The examined columns of different brands shared the observed behavior. Kinetic stability of a column state is adequate for successful application.The evaluated states of ADMPC provide multiple enantiorecognition potential by using mixtures of IPA and MeCN also considering the pretreatment of the column. Unprecedented double and triple elution order reversals along the composition range supported the versatility of the available states. Our findings further enhance the usefulness of ADMPC-containing CSPs. We provide instructions for the application of the widespread chiral selector in common eluent mixtures to avoid pitfalls regarding reproducibility and robustness.

Investigating the effect of solvent composition on ink structure and crack formation in polymer electrolyte membrane fuel cell catalyst layers

To improve the performance of polymer electrolyte membrane fuel cells (PEMFCs), controlling the microstructure of the membrane electrode assembly (MEA) catalyst layer is crucial. Ink design, which includes a catalyst, an ionomer, and a solvent, serves as the starting point for controlling the microstructure of the catalyst layer. However, there is a significant lack of understanding of the ink structure required for this purpose. In this study, we investigated the effect of the solvent, a key component that determines the ink structure. The ink comprises 20 wt% Pt/C, short-side-chain (SSC) Aquivion ionomer, and a solvent mixture of 1-propanol (NPA) and water. Three types of inks with different compositions of NPA and water are manufactured, and their stability and rheological properties were measured to infer and compare the ink structures. Furthermore, the crack characteristics of the catalyst layer were compared by directly coating the ink onto the electrolyte membrane using the doctor-blade method. In the ink with a high water content, we observed a gel-like elastic behavior dominated by network structures formed by ionomers adsorbed between catalyst particles. In contrast, the ink with a high NPA content exhibited a liquid-like viscous behavior dominated by well-dispersed catalyst particles and ionomers. These properties of the inks directly influence the crack formation characteristics after coating. Specifically, the strong liquid properties of the NPA-rich ink were found to suppress crack formation in the catalyst layer. These findings provide important insights into how the solvent composition affects ink structure and how it, in turn, influences crack formation in the catalyst layer, which can help optimize the ink design to improve the performance of PEMFCs.

Measurement and correlation of solubility data for deferiprone in propylene glycol and 2-propanol at different temperatures

This investigation dealt with the thermodynamic properties, saturated solubility values, and solvation behavior of deferiprone as an oral iron chelator agent in non-aqueous mixtures of propylene glycol and 2-propanol using experimental measurements and mathematical correlations. The solubility of deferiprone demonstrated a positive correlation with both temperature and propylene glycol mass fraction. Four mathematical models were employed to correlate the solid-liquid equilibrium data, and the low mean relative deviation values of less than 3.6% illustrate the good agreement of computed data with the experimental data. The apparent thermodynamic behavior of deferiprone dissolution was also investigated according to van’t Hoff and Gibbs equation.

Fingering Instability of Binary Droplets on Oil Pool

The interfacial instability of a complex fluid in a multiphase flow system is ubiquitous in both nature and industry. We experimentally investigated the spreading and interfacial instability dynamics of a binary droplet (a water and 2-propanol (IPA) mixture) on an immiscible (sunflower oil) pool. For droplets of 40 wt% IPA solution on sunflower oil, fingering instability occurred at the spreading liquid front. To reveal the interfacial characteristics of the spreading and fingering processes, we analyzed the interplay among the speed, diameter, and number of fingers on the spreading front. Based on our observations, the finger length, wavelength between the fingers, head length, and neck length were quantified. Our experimental results clearly demonstrate that fingering instability can be driven by the capillary effect for a liquid–liquid system as well as the Plateau–Rayleigh instability. We hope that our results will inspire further experimental and numerical investigations to provide deeper insights into the interfacial dynamics of multicomponent droplets in a liquid pool.

Phase equilibrium of three-component liquid systems composed of water, alcohol, and sodium chloride studied by the reference interaction-site model integral equation theory.

A theoretical method for calculating the thermodynamic properties and phase equilibria of a binary liquid mixture using the reference interaction-site model (RISM) integral equation theory, which we had proposed recently, was extended to ternary liquid systems containing salt. A novel dielectric correction of the RISM theory for a mixture of solvents was also proposed. The theory was applied to mixtures composed of water, alcohol, and NaCl, where the alcohol was either methanol or ethanol. The decrease in NaCl solubility with increasing alcohol molar fractions in the solvent was calculated. In the ethanol system, the theory yielded salt-induced liquid-liquid phase separation, which was observed experimentally in a ternary mixture of water, 1-propanol, and NaCl. The phase diagram of the ternary system was determined theoretically.

The oscillatory electro-oxidation of 2-propanol on platinum: the effect of temperature and addition of methanol.

The oscillatory electro-oxidation of 2-propanol on platinum and platinum-based catalysts has attracted growing attention in recent years due to its importance in the interconversion between chemical and electrical energies. This reaction might proceed with a very high selectivity to acetone, nearly without the formation of carbon dioxide, and the reversibility of the 2-propanol/acetone pair is very appropriate for hydrogen transfer. An important aspect of this system is the ubiquitous emergence of potential oscillations under current control, and it has been pointed out as a problem to be avoided and a primary cause of limitations to the use of 2-propanol in practical devices. Herein, we present an experimental study of the electrochemical instabilities in the electro-oxidation of 2-propanol on platinum. The system was studied using polycrystalline platinum, in acidic media and at different temperatures. Besides the extensive characterization of the potential oscillations, we have also discussed possible venues for engineering the dynamics to benefit from the potential oscillations. In this sense, we have also characterized the instabilities in the system containing a mixture of 2-propanol and methanol. The efficiency of a hypothetical fuel cell operated under different conditions is also presented.

SE‐ResNet‐based classifier for highly similar mixtures based on Raman spectrum: Classification for alcohol systems as an example

AbstractRaman spectroscopy is widely used in the identification of substances. Raman spectra contain molecular information from various components and interference from noise and instruments. Therefore, using Raman spectroscopy to identify components is still challenging, especially for substances with high similarity. In this study, a class of highly similar products (methanol and ethanol) and a multicomponent mixture of propanol and water were tested using a portable Raman spectrometer. They are divided into 11 categories according to the volume fraction ratio. A total of 5,060 groups of Raman spectrum data were obtained, constituting the data set of this study. The deep neural network structure adopted in this study is based on ResNet architecture, on which the SE module in the attention mechanism is added, which increases the weight of some spectral features and achieves significant performance improvement. Finally, SE‐ResNet achieves a recall of 0.95, a precision rate of 0.95, a Micro‐F1 of 0.95, and an accuracy rate of 99.20%.

Difference in the hydration state of water at the hydrophobic interface of structural isomers of propanol investigated by U.V visible absorption and Raman spectroscopic study

In this work, the nature of hydration shell water around hydrophobic groups of alcohol has been investigated by studying the U.V visible absorption energy shift of p-nitro-aniline upon interaction with water-alcohol mixture in different proportion. Analysis shows that, at low mole fraction of alcohol the absorption energy shift with composition of alcohol-water mixture originates from the interaction of hydrophobically modified water with PNA. It is further observed that, the absorption energy changes nonlinearly with the chain length of alkyl group of alcohol. From Raman studies it is apparent that, the absorption energy shift originates from the changing population of dangling OH interacting with PNA. The central part of the study has been to investigate the difference in the hydrophobic environment due to variation in the arrangement of hydrophobic groups in propanol. The U.V visible absorption studies of PNA in 1-propanol and 2-propanol water mixture show that 1-propanol bears higher population of dangling OH compared to 2-propanol. In addition, we have also performed Raman spectroscopic studies in the region of OH stretch. The spectra of hydration shell water are extracted by RD-SCF method. The characteristic peak due to dangling OH was analyzed and it also shows 1-propanol to possess relatively higher amount of dangling OH compared to 2-propanol. This joint study confirms that arrangement of hydrophobic moiety in small molecules can affect the water hydrogen bonding of water at the hydrophobic interface.

(Digital Presentation) Simulation of Agglomeration in Polymer Electrolyte Fuel Cell Catalyst Inks

Polymer electrolyte fuel cells (PEFCs) are expected to use as a power source for new generation automobiles, especially heavy-duty vehicles because of their low environmental affection. To be widely spread, it is essential to increase their power output and reduce the cost of catalyst platinum. Since oxygen reduction reaction (ORR) at the cathode is the dominant reaction, there is a need to improve the oxygen transport and proton conductivity. In recent years, porous carbon has been studied and it has been found its high activity and durability. However, the catalyst layer made of porous carbon gets a lower voltage than that made of non-porous carbon in the high current density area. This output reduction results from high oxygen transport resistance, but it is unclear how the porous structure influences the performance. So in this study, we assumed the following relation. Firstly, the difference in voltage at a high current density between carbons results in oxygen transport properties. Secondly, their properties depend on an effective oxygen diffusion coefficient, which is determined by the porous structure in the catalyst layer. And finally, the factor that attributes the catalyst layer structure is the size of the agglomerate in the catalyst ink because the catalyst layer is fabricated by the wet process. Therefore, we focused on the particle agglomeration process in catalyst ink and calculated the agglomerate behavior under various ink conditions using a numerical model. The differences in the agglomeration and its factors were also examined for carbon with different internal pores.A three-dimensional discrete element method (DEM) was used to calculate agglomeration. Initially, aggregates, the smallest unit of carbon black, were placed randomly in the cubic region. In this simulation, aggregates were regarded as spheres. The distance of movement was determined by solving the equation of motion. For each particle, the fluid drag, Brownian motion, and particle interactions were considered. The particle-particle interaction included the forces based on DLVO theory [1] and the ionomer effect. Several studies show that ionomer adsorbed on the carbon aggregates improves their stability. So it was assumed that the ionomer effect was the repulsive force and modeled using the same equation as for the EDL force. The dielectric constant dependence of this effect was used in the function previously reported by Magnus et al. [2]. The carbon particles assumed here were non-porous (Vulcan) and porous (Ketjen), and were coated with Pt particles. The initial average diameter of the aggregates was 300 nm. Hamaker coefficient was expressed as an average of the physical properties of platinum and carbon black, which was weighted by the percentage of platinum loaded on the surface of the carbon particles. The solvent was a mixture of 1-propanol (NPA) and water, and the dielectric constant of the ink was expressed as a weighted average of the composition ratio of water and NPA. The simulation was conducted under various water/alcohol ratios and ionomer/carbon ratios (I/C). From this model, it was confirmed that the carbon internal pores affect the size of the agglomerate in the catalyst ink.

Comments on excess molar volumes reported in “Study of short range and long range molecular interactions in binary liquid mixtures of N,N-dimethylformamide (DMF) and 1-propanol”

• V m E values of Prajapati and coworkers compared to published literature data of ten other researchers. • Published V m E values are much smaller in absolute magnitude than values of Prajapati and coworkers. • Published V m E versus mole fraction curves show simple parabolic behavior. • V m E versus mole fraction curves of Prajapati and coworkers show several local minima and maxima. A polemic is given concerning the volumetric properties reported for binary N,N-dimethylformamide + 1-propanol mixtures in the published paper by Prajapati and coworkers. The reported excess molar volumes differ significantly from the published literature values of ten independent research groups, all of which are much smaller in absolute magnitude than the values reported by Prajapati and coworkers.

Potential Impacts of Prunus domestica Based Natural Gum on Physicochemical Properties of Polyaniline for Corrosion Inhibition of Mild and Stainless Steel.

The lack of an eco-friendly approach towards application of polyaniline as a coating material has been one of the most challenging tasks. Herein, the synthesis of green Prunus domestica gum grafted polyaniline (PDG-g-PANI) composite is reported by a cost-effective emulsion polymerization for application as an efficient anti-corrosion material for mild steel (MS) and stainless steel (SS) in a strong corroding environment. The composite formation was confirmed by Ultraviolet Visible (UV-Visible) and Fourier Transformed Infrared (FTIR) spectroscopies. X-ray diffraction data revealed the amorphous nature of the PDG-g-PANI. Scanning Electron Microscopic (SEM) images showed a bi-layered structure having a parent porous layer of PANI coated with afibrous layer of PDG. The solubility test confirmed the dissolution of PDG-g-PANI in common organic solvents such as acetone, ethanol, propanol, butanol, chloroform, N-Methyl-2-pyrrolidone, dimethyl sulfoxide, and the mixture of propanol and chloroform. The polarization curve, open circuit potential, electrochemical impendence spectroscopy (EIS), and gravimetric analysis were applied to investigate the corrosion protection behavior of the composite on MS and SS in 3.5% NaCl and 1 M H2SO4 solution. The PDG-g-PANI-coated MS exhibited 96% corrosion inhibition efficiency as compared to 86% and 43% for pristine PANI and PDG in 3.5% NaCl solution while PDG-g-PANI-coated SS showed 98% corrosion inhibition efficiency. Moreover, 99% and 96.6% corrosion protection was observed for PDG-g-PANI-coated MS and SS in 1 M H2SO4 solution. Gravimetric studies revealed that PDG-g-PANI coating can protect MS up to 93% for 14 days in salt solution while 97% corrosion inhibition efficiency was retained for 2 months in open air.

Mutable bubble surface mobility in water – propanol mixtures and its impact on bubble motion and deformation

Various anomalies are typical for aqueous solutions of simple alcohols, with viscosity maxima and changing bubble surface mobility being significant for multiphase systems. Three regions of the hydrodynamic behaviour of spherical and ellipsoidal bubbles are described, depending on the propanol concentration. At low concentration (xP ≤ 0.005), alcohol behaves as a surfactant and the increase in concentration increases the drag coefficient and decreases bubble deformation. At intermediate concentration, the increase of concentration leads to more deformed bubbles with increasing rise velocity, because of the advantage of formation of bulk clusters. At high concentration (xP ≥ 0.07), bubbles behave as fully mobile with a low drag coefficient. Because of the fast desorption of molecules from the bubble surface, neither a concentration gradient nor a surface tension gradient arises, and thus the conditions for bubble surface mobility are fulfilled. The transition in the hydrodynamic behaviour is evident for all bubble sizes.

Combustion, performance and emission analysis of propanol addition on safflower oil biodiesel in a diesel engine

Studies on alternative and renewable fuels are maintaining due to the ever-decreasing of petroleum usage and also the environmental pollution that it has created. Alternative fuels, especially renewable fuels are one of the most emphasized issues because renewable energy sources are environmentally friendly, unconsumable and easily degradable in the environment. In this study, biodiesel was obtained from safflower. The biodiesel of safflower oil was mixed with propanol at different ratios and tested as a diesel engine fuel. The effects of both biodiesel and propanol addition on engine performance, combustion parameters and pollutant exhaust emissions have been experimentally tested. The main important point of the presented study is to detect the effects of higher ratios of pure diesel fuel in diesel engines by utilizing the positive sides of a light alcohol, the propanol. The engine performance, specific fuel consumption and emission values of the biodiesel and propanol blended fuels did not show a significant difference compared to the diesel. In the loaded cases, the combustion parameters for all test fuels were obtained in a similar manner. Peak values of HRR in higher engine loads of blend fuels with high propanol were a bit higher. It is seen that there is a decrease in NOx emissions. Safflower biodiesel and propanol mixtures can be used as alternative fuels by adding to diesel fuel in certain amounts.

Direct CO2 capture from air with aqueous and nonaqueous diamine solutions: a comparative investigation based on 13C NMR analysis

Five different diamines, namely 1,2-diaminopropane, N,N-diethylethylenediamine, piperazine, 1-methylpiperazine and N,N,N',N'-tetramethylethylenediamine, have been investigated as liquid sorbents for the direct capture of CO2 from air (DAC – Direct Air Capture) in both aqueous and non-aqueous solutions, using a 1:1 (volume scale) mixture of ethylene glycol and 1-propanol as an organic diluent. The capture performance of the 1.5 mol dm−3 diamine solutions was evaluated on the basis of the CO2 absorption efficiency from an atmospheric air stream, continuously measured by means of a gas chromatograph during 24-hour bench-scale absorption experiments, carried out in an absorption column maintained at 25°C. The carbonated species formed in solution upon the CO2 uptake and their relative amounts were evaluated by 13C NMR spectroscopy, a powerful non-invasive analytical technique that can provide valuable information on the reaction mechanisms. The correlations between the aerial CO2 absorption efficiency, the chemical structure of diamines and the carbonated species formed in their different solutions during capture were presented and discussed. Furthermore, the CO2 capture performance in DAC processes of the diamine solutions was compared to that of some of the more conventional alkanolamine solutions under the same operating conditions.