Alkanol Chain Length Research Articles

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.

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.

ChemInform Abstract: Thermophysical Contribution of N,N‐Dimethylformamide in the Molecular Interactions with Other Solvents

AbstractReview: 158 refs.

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.

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.

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.

Excess molar volumes of N, N-dimethylformamide + 2-pentanone + alkan-1-ols mixed solvent systems at 303.15 K

Accurate excess molar volumes ( V E), at ambient pressure and 303.15 K, have been determined in the ternary liquid mixtures of N, N-dimethylformamide (DMF) + 2-pentanone (PE) + 1-alkan-1-ols (C 3–C 6) and in the binary mixtures of PE + alkan-1-ols (C 3–C 6) as a function of composition. The alkanols include 1-propanol, 1-butanol, 1-pentanol and 1-hexanol. The intermolecular interactions and structural effects were analyzed on the basis of the measured and derived properties. Excess molar volumes increase in magnitude with increase in chain length of alcohol. Valuable information on the behavior and governing factors of the liquid structure of the strongly associated solvents studied were inferred from the parameters deduced. The V E results were correlated and fitted by the Redlich–Kister equation for binary mixtures and by the Cibulka equation for ternary mixtures, as a function of mole fraction. Several predictive empirical relations were applied to predict the excess volumes of ternary mixtures from the binary mixing data. An analysis of the data indicates a good agreement between experimental results and predicted values in all ternary systems. A discussion is presented and deviations are interpreted in terms of size, shape, the position of ketone group, the chain length of alkanol and hydrogen bond effects in the liquid mixtures studied to explain chemical and thermophysical behavior.

Influence of solvent on the growth of ZnO nanoparticles

We have synthesized ZnO nanoparticles by precipitation from zinc acetate in a series of n-alkanols from ethanol to 1-hexanol as a function of temperature. In this system, nucleation and growth are relatively fast and, at longer times, the average particle size continues to increase due to diffusion-limited coarsening. During coarsening, the particle volume increases linearly with time, in agreement with the Lifshitz–Slyozov–Wagner (LSW) model. The coarsening rate increases with increasing temperature for all solvents and increases with alkanol chain length. We show that the rate constant for coarsening is determined by the solvent viscosity, surface energy, and the bulk solubility of ZnO in the solvent.

Spectroscopic probing of the effect of alkanols on the properties of the head group region in reverse micelles of AOT–heptane–water

The effects of addition of alkanols (ethanol, n-hexanol, and 3-ethyl-3-pentanol) on the micropolarity and microviscosity of the head group region in reverse micelles of AOT–heptane–water have been investigated by fluorescence probing methods (ANS fluorescence yield and TMADPH fluorescence anisotropy), complemented by the use of the solvatochromic probe E T (30) in absorption spectroscopy. For all the alkanols considered, ANS fluorescence in AOT reverse micelles (at W=3) is quenched by additive incorporation, being the effect elicited almost independent of the alkanol chain length and topology. As sensed by the E T (30) parameter, the micropolarity of the micelle surface increases, remains unmodified, and decreases upon addition of ethanol, 3-ethyl-3-pentanol, and hexanol, respectively. While ethanol barely modifies the fluorescence anisotropy of TMADPH, 3-ethyl-3-pentanol and n-hexanol addition strongly decrease it. The similarity of the tendencies of ANS data to TMADPH anisotropies and the differences between ANS data and E T (30) values would indicate that, at least for 3-ethyl-3-pentanol and n-hexanol, microviscosity, rather than micropolarity, must be considered to interpret the effect of the alkanols upon the fluorescent behavior of ANS.

Studies of viscosity and excess molar volume of binary mixtures: 4. 1-Alkanol + tri- n-butylamine mixtures at 303.15 and 313.15 K

The excess molar volume V E, the viscosity deviation Δ η and the excess Gibbs energy of activation Δ G ∗E of viscous flow are calculated from density and viscosity measurements of six mixtures of 1-propanol, 1-butanol, 1-pentanol, 1-heptanol, 1-octanol and 1-decanol with tri- n-butylamine over the entire range of mole fractions at 303.15 and 313.15 K. The values of V E of all six systems are very large and negative. Except for 1-propanol+tri- n-butylamine, the magnitude of negative deviations in viscosity increases with chain length of alkanol. The results have been explained considering mixed associated species of type A i B involving alkanol (A) with tri- n-butylamine (B) through OH⋯N bonds. The viscosity data have been correlated with the equations of Grunberg and Nissan, Tamura and Kurata, Hind, McLaughlin and Ubbelohde, Katti and Chaudhri, McAllister, Heric, and of Auslaender.

Studies of viscosity and excess molar volume of binary mixtures: 3. 1-Alkanol+di- n-propylamine, and+di- n-butylamine mixtures at 303.15 and 313.15 K

The excess molar volume V E, the viscosity deviation Δ η and the excess Gibbs energy of activation Δ G ∗E of viscous flow have been investigated from density and viscosity measurements of 15 mixtures of ethanol, propanol, butanol, pentanol, heptanol, octanol and decanol with di- n-propylamine, and di- n-butylamine, and of hexanol with di- n-butylamine over the entire range of mole fractions at 303.15 and 313.15 K. The V E of all the systems are very large negative. Except for the ethanol with di- n-propylamine and di- n-butylamine mixtures, the magnitude of negative deviations in viscosity increases with chain length of alkanol. The results have been explained considering mixed association of alkanol with diamine through OH⋯N bond. The viscosity data have been correlated with the equations of Grunberg and Nissan, Tamura and Kurata, Hind, McLaughlin and Ubbelohde, Katti and Chaudhri, McAllister, Heric, and of Auslaender.

Excess molar volumes of binary mixtures of alkanols with ethyl acetate from 298.15 to 323.15 K

Excess molar volumes V E have been investigated from density ρ measurements using vibrating-tube digital densimeter DMA 60/602 for binary mixtures of methanol, 1-propanol, 2-propanol and 1-hexanol with ethyl acetate in the temperature range 298.15–323.15 K. Thermal expansion coefficients α and their excess values α E were evaluated. The results were analyzed and discussed in terms of dependence of V E on chain length of alkanol and position of hydroxyl group and effect of temperature.

Dispersed Molecular Aggregates: II. Synthesis and Characterization of Nanoparticles of Tungstic Acid in H2O/(TX-100+Alkanol)/n-Heptane W/O Microemulsion Media

Colloidal dispersions of tungstic acid (H2WO4) have been prepared in water/(TX-100+alkanol)/n-heptane water-in-oil microemulsion media by reacting Na2WO4 with HCl. The effects of alkanol chain length, TX-100/alkanol mass ratio, temperature, and dilution at different [water]/[TX-100] mole ratios (ω) have been studied by the dynamic light scattering technique. The formation of H2WO4 in the microwater pool has been established by FT-IR measurements. The particle sizes and shapes in microemulsion media and in isolated states have been measured by TEM and SEM techniques. The enthalpy of formation of H2WO4 in the water pool of the microemulsions has also been determined microcalorimetrically.