Alkanol Chain Research Articles

Better Choice of Tertiary Alkanolamines for Postcombustion CO2 Capture: Structure with Linear Alkanol Chain Instead of Branched

To give better guidance of tertiary alkanolamine selection with proper structures for postcombustion CO2 capture, effects of the alkanol chain structure and intramolecular hydrogen bond were invest...

Effect of alkanol chain length of primary alkanolamines and alkyl chain length of secondary and tertiary alkanolamines on their CO2 capture activities

Abstract The effect of the alkanol chain length in primary alkanolamines and the alkyl chain length in secondary and tertiary alkanolamines on CO 2 absorption and desorption kinetics, equilibrium CO 2 loading, heat duty, cyclic capacity, and pKa were studied. A selection strategy developed in our earlier work was used to identify potential solvents which could be used in a blend. Based on the strategy, alkanolamines that had a combination of high absorption parameter and high desorption parameter should be selected. The results of this study showed that, for absorption parameters, longer alkanol chain lengths of primary alkanolamines and longer alkyl chain lengths of secondary and tertiary alkanolamines led to higher equilibrium CO 2 loading and pKa. However, the influence of mass transfer limitations on these positive effects resulted in a maximum trend for initial rate of CO 2 absorption for secondary and tertiary alkanolamines. On the other hand, for the desorption parameters, the increase in the chain lengths also caused the generation of larger amounts of bicarbonate ions which resulted in higher CO 2 desorption rates and cyclic capacity, but lower heat duty. However, the longer chain alkanolamines also had high viscosities which adversely modified their performance by also introducing mass transfer limitations. Based on chain length alone, BMEA came out as the best overall alkanolamine component which could be used in a blend.

Thermophysical study of the binary mixtures of N , N -dimethylacetamide with 1-propanol and 1-butanol

Abstract Several thermophysical properties such as densities, ρ, speeds of sound, u, refractive indices, nD, and kinematic viscosities, ν, have been measured for the binary mixtures of N,N-Dimethylacetamide with 1-propanol and 1-butanol over the entire range of composition, at the temperatures (283.15, 298.15 and 313.15) K and at atmospheric pressure p = 0.1 MPa. From these experimental data, excess molar volumes, VE, excess isentropic compressibilities, κSE, refractive index deviations, ΔnD, and viscosity deviations, Δη, were calculated. Then, correlated with the Redlich-Kister equation and the corresponding parameters were drived. The results obtained, were discussed in terms of structural effects and specific molecular interactions, and the influence of the alkanol chain length was also considered.

Effect of alkanol chain length on excess thermodynamic properties of p-cresol with 1-alkanol (C3–C8) at 298.15, 303.15, 308.15 and 313.15 K

The objective of the present study is to accredit the molecular interactions between p-cresol and 1-alkanols at different temperatures, based on the thermophysical properties such as densities (ρ) and speed of sound (u) data. To improve our understanding of the molecular interactions between 1-alkanols such as 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol with p-cresol have been measured as a function of composition at different temperatures from (298.15 to 313.15) K and at atmospheric pressure. From these experimental data, the excess volumes (VE), isentropic compressibilities (ks) and excess isentropic compressibilities (ksE) have been calculated for 1-alkanols with p-cresol. The measured excess properties were correlated with the Redlich–Kister polynomial equation. The calculated properties were discussed in terms of molecular interactions between component molecules.

Regulation of a Notch3-Hes1 pathway and protective effect by a tocopherol-omega alkanol chain derivative in muscle atrophy.

Muscular atrophy, a physiopathologic process associated with severe human diseases such as amyotrophic lateral sclerosis (ALS) or cancer, has been linked to reactive oxygen species (ROS) production. The Notch pathway plays a role in muscle development and in muscle regeneration upon physical injury. In this study, we explored the possibility that the Notch pathway participates in the ROS-related muscular atrophy occurring in cancer-associated cachexia and ALS. We also tested whether hybrid compounds of tocopherol, harboring antioxidant activity, and the omega-alkanol chain, presenting cytoprotective activity, might reduce muscle atrophy and impact the Notch pathway. We identified one tocopherol-omega alkanol chain derivative, AGT251, protecting myoblastic cells against known cytotoxic agents. We showed that this compound presenting antioxidant activity counteracts the induction of the Notch pathway by cytotoxic stress, leading to a decrease of Notch1 and Notch3 expression. At the functional level, these regulations correlated with a repression of the Notch target gene Hes1 and the atrophy/remodeling gene MuRF1. Importantly, we also observed an induction of Notch3 and Hes1 expression in two murine models of muscle atrophy: a doxorubicin-induced cachexia model and an ALS murine model expressing mutated superoxide dismutase 1. In both models, the induction of Notch3 and Hes1 were partially opposed by AGT251, which correlated with ameliorations in body and muscle weight, reduction of muscular atrophy markers, and improved survival. Altogether, we identified a compound of the tocopherol family that protects against muscle atrophy in various models, possibly through the regulation of the Notch pathway.

Measurement and Correlation of Excess Molar Enthalpy of Binary Mixtures Containing Butyl Acetate + 1-Alkanols (C1–C6) at 298.15 K

Excess molar enthalpies, ∆H m E , for the binary mixtures of butyl acetate + 1-alkanols, namely (methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, and 1-hexanol), were measured over the whole range of composition at 298.15 K using a Parr 1455 solution calorimeter. The excess partial molar enthalpies, ∆H m, E , were calculated from the experimental excess molar enthalpies using the Redlich–Kister polynomial equation. The sign of ∆H m E for all systems are positive because of the disruption of hydrogen bonding and dipole–dipole interactions in the alkanols and esters, respectively. The magnitude of the ∆H m E values increases with increasing alkyl chain length. The behavior of ∆H m E was analyzed in terms of the length of the alkanol chain, the nature and type of intermolecular interactions and the balance between positive and negative effects on deviations from ideality. The experimental excess molar enthalpy data have also been correlated using the Redlich–Kister and SSF equations and two local composition models (UNIQUAC and NRTL).

Volumetric properties of piperidine + 1-alkanol binary liquid mixtures experimental results and application of Prigogine–Flory–Patterson theory

Densities of binary liquid mixtures of piperidine with methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol and1-octanol have been measured at 293.15, 298.15, 308.15 and 313.15K and at atmospheric pressure, over the entire range of composition, with a vibrating u-tube densimeter. Density data were used to calculate the excess molar volumes VE. All the mixtures exhibit large and negative VE value over the whole mole fraction range indicating strong interactions between unlike molecules. These interactions increase with increasing alkanol chain length and are far stronger for piperidine+methanol system. Temperature effect on VE is insignificant. Experimental VE values were fitted with the Redlich–Kister equation. Partial molar volumes at infinite dilution were also determined. Finally, the applicability of the Prigogine–Flory–Patterson theory was tested and discussed.

Rewiring the wax ester production pathway of Acinetobacter baylyi ADP1.

Wax esters are industrially relevant high-value molecules. For sustainable production of wax esters, bacterial cell factories are suggested to replace the chemical processes exploiting expensive starting materials. However, it is well recognized that new sophisticated solutions employing synthetic biology toolbox are required to improve and tune the cellular production platform to meet the product requirements. For example, saturated wax esters with alkanol chain lengths C12 or C14 that are convenient for industrial uses are rare among bacteria. Acinetobacter baylyi ADP1, a natural producer of wax esters, is a convenient model organism for studying the potentiality and modifiability of wax esters in a natural host by means of synthetic biology. In order to establish a controllable production platform exploiting well-characterized biocomponents, and to modify the wax ester synthesis pathway of A. baylyi ADP1 in terms product quality, a fatty acid reductase complex LuxCDE with an inducible arabinose promoter was employed to replace the natural fatty acyl-CoA reductase acr1 in ADP1. The engineered strain was able to produce wax esters by the introduced synthetic pathway. Moreover, the fatty alkanol chain length profile of wax esters was found to shift toward shorter and more saturated carbon chains, C16:0 accounting for most of the alkanols. The study demonstrates the potentiality of recircuiting a biosynthesis pathway in a natural producer, enabling a regulated production of a customized bioproduct. Furthermore, the LuxCDE complex can be potentially used as a well-characterized biopart in a variety of synthetic biology applications involving the production of long-chain hydrocarbons.

Application of the NRTL method to correlate solubility of diosgenin

Using the synthetic method, the solubility of diosgenin in 1-hexanol and 1-heptanol was measured at temperatures from 300K to 329K by a laser monitoring observation technique at atmospheric pressure. The solubility data were correlated by semi-empirical equations, such as the Apelblat equation, λh model and the ideal model, which agreed well with experimental results. The fusion enthalpy and the melting point determined by differential scanning calorimeter (DSC), are −34064.2J·mol−1 and 207.09°C for diosgenin. With collection of over 14 solvents from different references, the NRTL thermodynamic model as one of the activity coefficient models was used to correlate and predict the solubility of diosgenin. The solubility calculated for all solvents showed good agreement with the experimental results within the temperature range studied. Additionally, the solubility of diosgenin in 14 solvents is also investigated at T=308.15K, the results of which indicated that solubility of diosgenin in n-alkanols tends to increase with increasing alkanol chain length from methanol to 1-heptanol and n-alkanols presented higher solubility than heterogeneous alcohols for diosgenin, such as 1-butanol>isobutyl alcohol>tert-butanol and 1-propanol>isopropanol. It also shows that solubility of diosgenin decreases with the increasing polarity of solvents. Its corresponding (solid+liquid) equilibrium data will provide essential support for industrial design and further detailed theoretical studies.

Excess molar volumes, excess molar enthalpies and refractive index deviations for binary mixtures of propan-1-ol, butan-1-ol and pentan-1-ol with 2,2,4-trimethylpentane at 298.15 K

Density (ρ), refractive index (nD), and molar excess enthalpy (HE) of binary mixtures of propan-1-ol with 2,2,4-trimethylpentane, butan-1-ol with 2,2,4-trimethylpentane and pentan-1-ol with 2,2,4-trimethylpentane at 298.15K and ambient pressure have been experimentally measured in the whole composition range. Excess molar volumes (VE), deviation of refractive indices (ΔnD), deviations of molar refraction (ΔR) and HE data were correlated with Redlich–Kister equation. Refractive indexes estimates were carried out using several mixing rules. An estimation of density of the binary mixture was performed using the equation suggested by Nakata and Sakurai [35] using the Lorentz–Lorenz refractive index mixing rule with densities and refractive indexes of the pure substances. Wilson and Non Random Two Liquids (NRTL) models were applied for HE correlation. The Prigogine–Flory–Patterson (PFP) and Extended Real Association Solution (ERAS) theories have been used to correlate the excess molar volumes of the mixtures. The behavior of the thermophysical properties was analyzed in terms of the length of the alkanol chain and the balance between positive and negative deviations of the ideality.

Measurement and correlation of the excess molar enthalpy of (1-nonanol, or 1-decanol + acetonitrile) mixtures at (298.15, 303.15, and 308.15) K and atmospheric pressure

Experimental excess molar enthalpies H m E of binary liquid mixtures containing (1-nonanol, or 1-decanol + acetonitrile) have been determined as a function of composition at atmospheric pressure and (298.15, 303.15, and 308.15) K using a modified 1455 Parr solution calorimeter. The experimental values are positive for both systems over the whole composition range, and increase with temperature and with alkanol chain length. The Extended Real Associated Solution Model (ERAS-Model) allowing for self-association of the alkanols and complex formation between acetonitrile and alkanols have been used to correlate experimental data. Agreement between theoretical and experimental values is satisfactory.

Grain size modulation on BaTiO 3 nanoparticles synthesized at room temperature

A new method is developed to synthesize massive BaTiO 3 nanoparticles directly at room temperature. With this method, the synthesis efficiency is improved and mass preparation can be realized. Also, the grain size of the as-prepared nanoparticles can be modulated from several nanometers to 40 nm through proper selection of the content of water and the alkanol chain length of the dispersant. It was found that smaller water content and a larger alkanol chain length of the dispersant will lead to a finer grain size. The mechanisms of the grain size modulation of BaTiO 3 nanoparticles are also discussed.

Structure of Aggregates in Diluted Aqueous Octyl Glucoside/Tetraethylene Glycol Monododecyl Ether Mixtures with Different Alkanols

A systematic study of the diluted lamellar phases of the OG/C(12)E(4) system with different alkanols has been carried out by small-angle X-ray scattering (SAXS). The measurements have been made as a function of both the concentration and the alcohol type. Several different form factor models have been used to estimate the differences in bilayer topology induced by the presence of alcohol. For the infinite lamellae form factor (with a high-low-high electronic density profile across the membrane), there is a good fitting of samples with a X(OG) = 0.1 ratios. Only the free parameters correspond to the pseudomolecule composition and hydration number, which resulted in two water molecules per ethylene oxide group in the polar head irrespective of the alkanol chain length and concentration. However, samples with higher OG content can be quite well fitted by a core-shell disk model. For the samples with higher OG content, we find the participation of OG in the disks to be important. From the line-shape analysis of SAXS data, the half-thickness of the hydrophobic layer and the thickness of the hydrophilic layer have also been obtained. The results suggest significant mixing of the surfactant acyl chains corresponding to both sides of the lamellae and the transition from vesicles to open bilayer fragments without macroscopic phase separation.

The effect of alkanol chain on the interfacial composition and thermodynamic properties of diesel oil microemulsion

The interfacial and thermodynamic properties of water/cetyltrimethylammonium chlorine (CTAC)/alkanol/diesel oil w/o microemulsion systems were investigated by the method of dilution. Alkanols with different carbon numbers ( n-butanol, n-pentanol, iso-pentanol, n-hexanol, n-octanol) were used to investigate the effect of cosurfactant on the formation of diesel oil microemulsion. The composition of the cosurfactant and the surfactant in the interfacial region, the distribution of the cosurfactant between the interfacial region and the continuous oil phase, and the energetics of transfer of the cosurfactant from the oil to the interface were estimated.

Thermodynamic Properties of 1-Butyl-3-methylpyridinium Tetrafluoroborate and Its Mixtures with Water and Alkanols

In this article, we study the behavior of an ionic liquid (IL) derived from pyridinium, 1-butyl-3-methylpyridinium tetrafluoroborate [b3mpy][BF4], in mixtures with water and with the first alkanols of the series from methanol to butan-1-ol, at the temperatures of (298.15 and 318.15) K. First, the miscibility regions with the alkanols were established at these two temperatures, determining experimentally the liquid−liquid equilibria and the upper critical solution temperature (UCST) for each binary mixture, confirming the quasiexponential variation of the UCST with the alkanol chain. The enthalpies were determined experimentally with a newly designed calorimetric cell, and the excess molar volumes were determined from densities, at (298.15 and 318.15) K. In all cases, the are positive with (d /dT)p > 0, whereas the are negative for mixtures with alkanols but positive for the mixture of IL + water. The thermal coefficient (d /dT)p > 0 was also positive in all cases. All data were correlated with a suitable polynomial equation, and the area and volume parameters of [b3mpy][BF4] were calculated. Finally, we give an interpretation of the results and of the behavior of the mixtures.

Synthesis of New Bis‐imidazole Derivatives

AbstractThe reaction of aldimines with α‐(hydroxyimino) ketones of type 10 (1,2‐diketone monooximes) was used to prepare 2‐unsubstituted imidazole 3‐oxides 11 bearing an alkanol chain at N(1) (Scheme 2, Table 1). These products were transformed into the corresponding 2H‐imidazol‐2‐ones 13 and 2H‐imidazole‐2‐thiones 14 by treatment with Ac2O and 2,2,4,4‐tetramethylcyclobutane‐1,3‐dithione, respectively (Scheme 3). The three‐component reaction of 10, formaldehyde, and an alkane‐1,ω‐diamine 15 gave the bis[1H‐imidazole 3‐oxides] 16 (Scheme 4, Table 2). With Ac2O, 2,2,4,4‐tetramethylcyclobutane‐1,3‐dithione or Raney‐Ni, the latter reacted to give the corresponding bis[2H‐imidazol‐2‐ones] 19 and 20, bis[2H‐imidazol‐2‐thione] 21, and bis[imidazole] 22, respectively (Schemes 5 and 6). The structures of 11a and 16b were established by X‐ray crystallography.

Vaporization and layering of alkanols at the oil/water interface

This study of adsorption of normal alkanols at the oil/water interface with x-ray reflectivityand tensiometry demonstrates that the liquid to gas monolayer phase transition at thehexane/water interface is thermodynamically favourable only for long-chain alkanols. Asthe alkanol chain length is decreased, the change in excess interfacial entropy per areaΔSaσ decreases to zero. Systems with small values ofΔSaσ formmulti-molecular layers at the interface instead of the monolayer formed by systems with much largerΔSaσ. Substitution of n-hexane by n-hexadecane significantly alters the interfacial structure for agiven alkanol surfactant, but this substitution does not fundamentally change the phasetransition behaviour of the monolayers. These data show that the critical alkanol carbonnumber, at which the change in excess interfacial entropy per area decreases to zero, isapproximately six carbons larger than the number of carbons in the alkane solventmolecules.

Interfacial and Thermodynamic Properties of Formation of Water‐in‐Oil Microemulsions with Surfactants (SDS and CTAB) and Cosurfactants (n‐Alkanols C5–C9)

The interfacial and thermodynamic properties of water‐in‐oil microemulsion systems consisting of water, isopropyl myristate, n‐alkanol, and surfactant have been investigated using the method of dilution. The surfactants used were hexadecyl trimethylammonium bromide and sodium dodecylsulfate, and the cosurfactants were n‐alkanols with varying chain length from (C5–C9). The distribution of cosurfactant (n‐alkanol) between the interface of water and oil regions at the threshold level of stability as well as the energetics of the transfer of the cosurfactant from the oil to the interfacial region have been examined as a function of varying cosurfactant chain length (C4–C9) and temperature. The structural parameters (including dimension, population density and effective water pool radius) of the dispersed water droplets in the oil phase have also been evaluated and correlated with alkanol chain length.

Experimental investigation of the reversible collapse of a capped amphiphile Langmuir monolayer

Surface isotherms, Brewster angle microscopy (BAM), surface potential measurements, and ab initio calculations were used to examine Langmuir monolayer films of an amphiphile with a bulky group that caps the terminus of an alkanol chain. BAM images of the collapsed state differ significantly from those of long-chain paraffinic amphiphiles. The collapsed phase BAM images show that aggregates of these amphiphiles extrude to form a three-dimensional phase. These clusters are able to easily reform the pre-collapse monolayer upon release of the applied surface pressure to pre-collapse values. This system may be described over all accessible surface pressures as a two-dimensional liquid-crystal analog at temperatures near and above room temperature. The behavior of this amphiphile is suggested to be related to structural elements of the molecule, particularly the bulky capping group, that may define a class of such systems.

ERAS modeling of the excess molar enthalpies of binary liquid mixtures of 1-pentanol and 1-hexanol with acetonitrile at atmospheric pressure and 288, 298, 313 and 323 K

This work reports experimental data on the excess molar enthalpy H m E as a function of composition of acetonitrile + 1-pentanol and acetonitrile + 1-hexanol mixtures at 288.15, 298.15, 313.15 and 323.15 K under atmospheric pressure. The data show positive values over the whole composition range for both systems and for all temperatures studied, they also increase with temperature and with alkanol chain length. The experimental curves have a parabolic shape with maximum point around 0.5 mole fraction. The extended real associated solution (ERAS) model was applied to correlate the experimental data. The ERAS model adequately described the main features of the H m E behavior of the mixtures.