Nonpolar Organic Liquids Research Articles

Water/organic liquid interface properties with amine, carboxyl, thiol, and methyl terminal groups as seen from MD simulations.

Molecular dynamics simulations were performed to study structural and dynamic properties of polar butanamine/water/butanamine, pentanoic acid/water/pentanoic acid, butanethiol/water/butanethiol, and nonpolar pentane/water/pentane systems. The mass density profiles along the interface normal to the organic liquid/water system, the difference in the local structure of H O molecules in bulk and in the vicinity of interface, as well as the diffusion behavior of water molecules at the interface with above-mentioned organic liquids have been investigated. Our MD simulation has shown that the diffusion of water molecules across the water/organic liquid interface is influenced by the hydrogen bonds between water molecules and the terminal groups of organic liquids. It was found that the loss of the hydrogen bonds in the nonpolar organic liquid leads to a decrease in the value of the normal component of the diffusion coefficient , while the tangential diffusion coefficients, both and , increase.

Kaolinite surface charges developed in cyclohexane suspension with dissolved Span 80 or bitumen: Electrodeposition and adsorption/desorption studies

In this study, we investigated the surface charges of kaolinite particles suspended in cyclohexane with or without the addition of Span 80 or bitumen. Kaolinite particles did not carry a net charge when dispersed in cyclohexane. They were found to acquire positive charges after adding Span 80 and negative charges after adding bitumen. Furthermore, when Span 80 was removed from the cyclohexane solution, the kaolinite surface charges disappeared, but when bitumen was removed, the kaolinite particles remained negatively charged. Our investigations showed that the bitumen adsorbed on the kaolinite surface caused the negative surface charges of kaolinite in cyclohexane. This was different from the widely accepted conventional charging mechanism which states that solid particles in a nonpolar organic liquid acquire charges due to the formation of reverse micelles from added surfactants, such as Span 80, and the reverse micelles house and stabilize free opposite charges to maintain the net particle surface charge. On the other hand, bitumen-coated kaolinite could carry net charges in cyclohexane due to the selective dissolution of charge-carrying species induced by an external electric field. Our electrochemical quartz crystal microbalance with dissipation (EQCM-D) measurements showed that about 3.7 wt% of the adsorbed bitumen was desorbed from kaolinite surface under a 5 V external electric field. Elemental analysis showed that the carbon content on the surface of bitumen-coated kaolinite particles decreased from 4.43 wt% for suspended kaolinite particles to 4.21 wt% for kaolinite particles deposited on the electrodes. Both measurements revealed shedding of bitumen from the bitumen coating layer on kaolinite surface.

Ozone in Polar (Acetonitrile) and Nonpolar (Carbon Tetrachloride) Organic Liquids: Optical Absorption, Solubility, and Stability

AbstractThe optical characteristics, solubility, and decomposition kinetics of ozone in polar (acetonitrile, CH3CN) and nonpolar (carbon tetrachloride, CCl4) liquids in the temperature range 233.15–295.15 K were studied. The rate constants of the O3 decomposition at 295.15 K in CH3CN and CCl4 are 3.3×10−5 and 5.0×10−5 s−1, respectively. At low temperatures, ozone solutions are practically stable. The solubility coefficients at 295.15 K are 2.6 in CH3CN and 2.9 in CCl4; at 233.15 K, they increase to approximately 7.0. Thus, these two liquids have a set of properties making them optimum for studying the ozonolysis in polar and nonpolar media.

Photochemically Produced Superhydrophobic Silane@polystyrene‐Coated Polypropylene Fibrous Network for Oil/Water Separation

Cost-effective separation of oil and immiscible organic contaminants from water has become an urgent challenge to protect aquatic and human life from devastating effects. Therefore, it has become imperative to develop super-selective materials for efficiently separating oil from water. In this work, a superhydrophobic surface has been formed that consists of a silane@polystyrene-coated polypropylene fibrous network (silane@PS-PPF) for efficient separation of accidentally spilled oil from water. The superhydrophobic PPFs were designed by a simple, cost-effective two-step process that includes photochemically controlled polymerization of styrene and subsequent dip coating in octadecyltrichlorosilane solution. The hydrophobic surface (CA=129°±4°) of the PS coated PPF after treating with silane was turned into a superhydrophobic body (CA=161°±2°). The achieved silane@PS-PPF fibrous network selectively allowed the fast permeation of the oils and non-polar organic liquids by altogether rejecting water during operation. The separation efficiency for various oils from the contaminated water was 96 to 99%, with a high flux in the range of 7606±312 L m-2 h-1 to 9870±151 L m-2 h-1 . Apart from being used as a filter, the silane@PS-PPF was also used as an oil absorber and has shown an absorption capacity in the range of 1185 to 1535% for various oils. We anticipate that the developed silane@PS-PPF, due to its facile synthetic route, cost-effectiveness, and high performance, can be effectively used in oily wastewater treatment and clean-up of large oil spills from water.

Charging Organic Liquids by Static Charge.

Aqueous liquids can be charged effectively by a number of methods for many important applications. Organic liquids, however, cannot be charged effectively by existing methods due to their low conductivities, especially the insulating nonpolar organic liquids; hence, there has not been any significant application developed based on charged organic liquids. This study describes an effective fundamental strategy for charging organic liquids, including nonpolar organic liquids: static charge is simply mixed into the liquid. Analyses suggested that the charged species are molecular ions that reside in the bulk of the liquid after charging. This method is simple and general, and the amount and polarity of charge can be flexibly tunable. The effectiveness of this method gives rise to opportunities for the development of novel applications. Charged organic droplets are manipulated for the first time by an electric field for controlling organic reactions. Particles with charge embedded in their bulk matrices are fabricated for the first time (i.e., via polymerizing the liquid monomers mixed with static charge). The charge in this novel class of bulk-charged particles is stable and permanent, especially when compared to the typical surface-charged particles. Simultaneous bulk-charged and bulk-magnetic particles are fabricated for the first time via simply mixing both the static charge and magnetic nanoparticles into the liquid monomers. These highly versatile particles are responsive to both electric and magnetic fields for practical applications.

Separation of Mixtures of Polar and Nonpolar Organic Liquids by Pervaporation and Nanofiltration (Review)

The review summarizes the accumulated scientific results on the separation of mixtures of organic solvents by pervaporation and reverse osmosis. It has been shown that the pervaporation process makes it possible to achieve generally higher selectivity as compared to the reverse osmosis process; however, a number of developments, such as membranes from polyketone or PIM-1, make it possible to effectively separate components with similar molecular weights. Such membranes allow the main advantage of reverse osmosis—lower energy consumption due to the absence of phase transitions—to be gained. It is noted that with the use of reverse osmosis membranes, the highest efficiency can be achieved in the case of separation of mixtures of organic liquids that differ significantly in their polarity, a process that is especially important for the regeneration of polar extractants in the petrochemical industry.

Interface Energy of Crystal Faces of IIА-Type Metals at Boundaries with Nonpolar Organic Liquids, Allowing for Dispersion and Polarization Corrections

The effect an organic liquid has on the orientation dependence of the polarization and dispersion corrections to the interface energy of IIА-type metals is considered. The interface energy of metal crystal faces is determined within these corrections using the electron statistic approach. The interface energy is calculated as a function of the atomic number of the element and of concentration of particles at the face.

Особенности ультразвукового диспергирования терморасширенного графита

Thermally expanded graphite (TEG) is one of the best precursors for receiving of plane nano-dimensional particles. Crucible graphite of Taigin deposit was used as a basic material to receive TEG. It is established that repeated thermo-chemical, as well as additional mechanical TEG dispersion does not lead to formation of nano-dimensional graphite particles. In order to receive graphite particles with several nano-meters of thickness, TEG was treated by ultra-sound dispersion in four liquid mediums. Different influence of chosen liquid mediums on the process of ultra-sound dispersion of TEG particles is conditioned by peculiarities of liquids’ behavior in cavitation process, it is described integrally by a notion “erosion activity”. Erosion activity, in the first turn, depends on the superficial tension. The quantity of the received broken material is defined by the depth of penetration of the liquid into the body volume, which depends on liquid wettability. The used liquids: water, acetone, benzene and toluene had different polarity and superficial tension that allowed to put into reality different physical and chemical effects at TEG dispersion. Benzene has the lowest meaning of superficial tension, it moistens the graphite surface very well and penetrates easily into its micropores. Despite of the relatively low erosion capacity, non-polar organic liquids, penetrating to the big depth into the graphite particle’s volume are capable to provoke a visible breaking influence at ultra-sound dispersion on inner graphite structures and its breakage into plates. The best results of breakage are reached at use of benzene that has zero molecule polarity and the best wettability of graphite surface. At ultra-sound dispersion in all environments, plane graphite particles are received that are several dozens of nano-meters thick. However, some particles broken in ultra-sound have visible fluctuations from ideal plane form and can form complicated spatial figures of irregular structure. The received results may be a base for creation of a method for receiving of thin graphite plates with geometrical parameters that are necessary for making of composites and objects of nano-techniques.

Development of a Nonelectrolytic Selectively Superabsorbent Polymer

Highly absorbent polymers capable of trapping large volumes of organic liquids are attractive materials for cleaning up toxic chemical spills. Here we report development of a homopolymer network using N-butyl-N-phenylacrylamide with poly(ethylene glycol) dimethacrylate as the cross-linker, that absorbs a variety of organic liquids by swelling. The nonelectrolytic basis of this polymer allows it to be used in areas where organic liquids and water coexist in the form of an emulsion. We demonstrate that this new polymer swells up to 20× in nonpolar organic liquids and up to 33× in more polar organic liquids but has negligible swelling in water. Consequently, this novel selectively superabsorbent polymer has potential use in a broad range of applications to capture and remove hazardous materials.

Polarization Correction to the Interfacial Energy of Faces of Alkali Metal Crystals at the Borders with a Nonpolar Organic Liquid

Polarization is corrected using modified version of the electron-statistical theory of the interfacial energy at a metal–nonpolar organic liquid boundary. The dependence of the correction on the orientation and macroscopic dielectric permittivity of the liquid is established.

Volume change behaviour of swelling and non-swelling clays upon inundation with water and a low dielectric constant fluid

Studies of the volume change behaviour of saturated and unsaturated fine-grained soils upon exposure to various types of fluid are of significant interest while dealing with contaminated soils. In this study, the one-dimensional volume change behaviour of two clays (Spergau kaolin and Calcigel bentonite) with dominant minerals as kaolinite and montmorillonite was studied by inundating several initially unsaturated and saturated clay specimens with water and a non-polar organic liquid (heptane). For both cases, applied vertical pressures of 25 and 100 kPa were considered under oedometric conditions. The magnitude of compression and swelling deformations of the clays were found to be strongly dependent upon the mineralogy of clays, dielectric properties of the pore-fluid, initial compaction conditions, and applied stress during the wetting process. The test results indicated distinct interactions between unsaturated clays and water. Specimens of Spergau kaolin exhibited compression with water, whereas specimens of Calcigel bentonite exhibited swelling. Compression and swelling deformations of the clays with heptane as the inundating liquid remained within about ±1.0% for both clays indicating a very minor interaction between unsaturated clays and molecules of this non-polar organic liquid. The test results emphasized the significance of attractive and repulsive forces and their impact on the volume change behaviour of clays of different mineralogy.

Low-Density, Mechanical Compressible, Water-Induced Self-Recoverable Graphene Aerogels for Water Treatment.

Graphene aerogels (GAs) have demonstrated great promise in water treatment, acting as separation and sorbent materials, because of their high porosity, large surface area, and high hydrophobicity. In this work, we have fabricated a new series of compressible, lightweight (3.3 mg cm-3) GAs through simple cross-linking of graphene oxide (GO) and poly(vinyl alcohol) (PVA) with glutaraldehyde. It is found that the cross-linked GAs (xGAs) show an interesting water-induced self-recovery ability, which can recover to their original volume even under extremely high compression strain or after vacuum-/air drying. Importantly, the amphiphilicity of xGAs can be adjusted facilely by changing the feeding ratio of GO and PVA and it exhibits affinity from polar water to nonpolar organic liquids depended on its amphiphilicity. The hydrophobic xGAs with low feeding ratio of PVA and GO can be used as adsorbent for organic liquid, while the hydrophilic xGAs with high feeding ratio of PVA and GO can be used as the filter material to remove some water-soluble dye in the wastewater. Because of the convenience of our approach in adjusting the amphiphilicity by simply changing the PVA/GO ratio and excellent properties of the resulting xGAs, such as low density, compressive, and water-induced self-recovery, this work suggests a promising technique to prepare GAs-based materials for the water treatment in different environment with high recyclability and long life.

Orientation dependence of the interfacial energies of chromium and α-iron crystals at boundaries with nonpolar organic liquids

Interfacial energies of chromium and α-iron at boundaries with nonpolar organic liquids are calculated within the modified variant of the statistical electron method. Calculations are performed with allowance for dispersion, oscillatory, polarization corrections and the contribution from temperature. The dependence of the interfacial energy on the orientation of metallic crystals, and on the macroscopic dielectric permeability of the organic liquid, is established. The profiles of the potential and electron density at the boundary of the phase separation are considered.

Investigation the effect of super hydrophobic titania nanoparticles on the mass transfer performance of single drop liquid-liquid extraction process

Hydrophobic titania nanoparticles were synthesized by a novel in situ sol-gel method and applied in a single drop liquid-liquid extraction column to enhance the overall dispersed-phase mass transfer coefficient (Kod). The chemical system of toluene, acetic acid and water was used, and the direction of solute (acetic acid) mass transfer was from dispersed phase, including: toluene and acetic acid to the continuous phase of water. For such system, much of the mass transfer resistance exists in the dispersed phase, which is nonpolar organic liquid. Hence, modified titania nanoparticles (MTNP’s), prepared by sol-gel route, in five different concentrations of 0.001–0.005 wt.% were added in the dispersed phase. Also, the impact of MTNP’s at the different solute concentrations and nozzles was investigated. Results indicated an anomalous enhancement in the overall dispersed-phase mass transfer coefficient at 0.002 wt.% of MTNP’s. A maximum enhancement of 70% in the overall mass transfer coefficient was found in droplets formed from a nozzle of 2.5 mm inner diameter, containing 3 wt.% of solute. Eventually, based on the theoretical model of Newman, a semi-empirical model was presented, that is capable to predict the overall dispersed-phase mass transfer coefficient of nanofluids with an average absolute relative error of 8.6%.

Fabrication of Long-Term Underwater Superoleophobic Al Surfaces and Application on Underwater Lossless Manipulation of Non-Polar Organic Liquids

Underwater superoleophobic surfaces have different applications in fields from oil/water separation to underwater lossless manipulation. This kind of surfaces can be easily transformed from superhydrophilic surfaces in air, which means the stability of superhydrophilicity in air determines the stability of underwater superoleophobicity. However, superhydrophilic surfaces fabricated by some existing methods easily become hydrophobic or superhydrophobic in air with time. Here, a facile method combined with electrochemical etching and boiling water immersion is developed to fabricate long-term underwater superoleophobic surfaces. The surface morphologies and chemical compositions are investigated. The results show that the electrochemically etched and boiling-water immersed Al surfaces have excellent long-term superhydrophilicity in air for over 1 year and boehmite plays an important role in maintaining long-term stability of wettability. Based on the fabricated underwater superoleophobic surfaces, a special method and device were developed to realize the underwater lossless manipulation of immiscible organic liquid droplets with a large volume. The capture and release of liquid droplets were realized by controlling the resultant force of the applied driving pressure, gravity and buoyancy. The research has potential application in research-fields such as the transfer of valuable reagents, accurate control of miniature chemical reactions, droplet-based reactors, and eliminates contamination of manipulator components.

Enhanced ordering reduces electric susceptibility of liquids confined to graphene slit pores.

The behaviours of a range of polar and non-polar organic liquids (acetone, ethanol, methanol, N-methyl-2-pyrrolidone (NMP), carbon tetrachloride and water) confined to 2D graphene nanochannels with thicknesses in the range of 4.5 Å to 40 Å were studied using classical molecular dynamics and hybrid density functional theory. All liquids were found to organise spontaneously into ordered layers parallel to the confining surfaces, with those containing polar molecules having their electric dipoles aligned parallel to such surfaces. In particular, monolayers of NMP showed remarkable in-plane ordering and low molecular mobility, suggesting the existence of a previously unknown 2D solid-like phase. Calculations for polar liquids showed dramatically reduced static permittivities normal to the confining surfaces; these changes are expected to improve electron tunnelling across the liquid films, modifying the DC electrical properties of immersed assemblies of carbon nanomaterials.

Anisotropy of the interface energy of IA and IB metals at a boundary with organic liquids

A statistical electron technique for calculating the interface energy at a boundary with nonpolar organic liquids is proposed in the context of the Frenkel–Gambosh–Zadumkin theory. The anisotropy of the interface energy is determined. The general dependences of the interface energies of alkali metals, copper, silver, and gold on temperature, the atomic numbers of metals, and the dielectric permeability of the organic liquid are found.

Underwater Spontaneous Pumpless Transportation of Nonpolar Organic Liquids on Extreme Wettability Patterns

Spontaneous pumpless transportation (SPT) of liquids has generated tremendous demands in microfluidic systems and advanced devices. However, the transportation of nonpolar organic liquids on open platforms underwater remains a challenge because most existing SPT systems are only designed for use in air. Here, we report a surface-tension-driven SPT system to transport various nonpolar organic liquids using underwater extreme wettability patterns. The patterns were fabricated with a wedge-shaped superoleophilic track on a superoleophobic background by combining CuCl2 etching, stearic acid modification, and mask-based nitrogen cold plasma treatment. Three types of underwater SPT processes-horizontal transport, tilted transport, and directional transport-were studied experimentally and theoretically. For horizontal SPT and tilted SPT, the capillary force was the main driving force, which depended on the wedge angle of the superoleophilic track. The excellent transportation ability of horizontal SPT of underwater liquid droplets was obtained at a wedge angle of 3-5°. The maximum moving height of organic liquids on the tilted SPT transport was obtained at an angle of 8°. For directional SPT, organic liquids did not drop off in the moving process because of the constraint imposed by surface tension, resulting in the sustained directional transport with long distances and complex trajectories.

Insights into Mechanistic Models for Evaporation of Organic Liquids in the Environment Obtained by Position-Specific Carbon Isotope Analysis.

Position-specific isotope effects (PSIEs) have been measured by isotope ratio monitoring (13)C nuclear magnetic resonance spectrometry during the evaporation of 10 liquids of different polarities under 4 evaporation modes (passive evaporation, air-vented evaporation, low pressure evaporation, distillation). The observed effects are used to assess the validity of the Craig-Gordon isotope model for organic liquids. For seven liquids the overall isotope effect (IE) includes a vapor-liquid contribution that is strongly position-specific in polar compounds but less so in apolar compounds and a diffusive IE that is not position-specific, except in the alcohols, ethanol and propan-1-ol. The diffusive IE is diminished under forced evaporation. The position-specific isotope pattern created by liquid-vapor IEs is manifest in five liquids, which have an air-side limitation for volatilization. For the alcohols, undefined processes in the liquid phase create additional PSIEs. Three other liquids with limitations on the liquid side have a lower, highly position-specific, bulk diffusive IE. It is concluded that evaporation of organic pollutants creates unique position-specific isotope patterns that may be used to assess the progress of remediation or natural attenuation of pollution and that the Craig-Gordon isotope model is valid for the volatilization of nonpolar organic liquids with air-side limitation of the volatilization rate.

ChemInform Abstract: Dynamics and Structure of Room Temperature Ionic Liquids

AbstractReview: 149 refs.