Solvents N-heptane Research Articles

Experimental and simulation study on the solubility of 1-naphthylamine in twelve neat solvents

To meet the demand of separating and purifying 1-naphthylamine from the reaction production and filling the solubility data gap, the solubility of 1-naphthylamine in twelve pure solvents (acetone, acetonitrile, ethyl acetate, n-butyl acetate, cyclohexane, n-heptane, methanol, ethanol, n-propanol, iso-propanol, n-butanol, and iso-butanol) was experimentally investigated in the range from 273.15 K to 308.15 K. It was found that the solubility of 1-naphthylamine increases markedly with increasing temperature in all solvent systems. The maximum solubility was 0.8978 (in the solvent of acetone,T = 308.15 K) and the minimum solubility was 0.005485 (in the solvent of n-heptane, T = 273.15 K). Then the experimental solubility data was correlated by the modified Apelblat model, Van't Hoff model, NRTL model, Wilson model, and Margules model. ARD% was calculated to assess the accuracy of the five equations and the results indicated that the modified Apelblat model fits optimally with an average ARD% value of 1.62 %. The effects of various physicochemical properties such as solvent polarity, hydrogen bond donor, hydrogen bond acceptor, and cohesive energy density on solute dissolution behavior were explored. In addition, the apparent thermodynamic properties of 1-naphthylamine in different solvents were analyzed based on modified Van’t Hoff model, which indicated the dissolution process of 1-naphthylamine in selected solvents is endothermic and entropy-driving. Finally, the effect of intermolecular interactions on the dissolution behavior was investigated at the molecular scale through molecular dynamics simulation studies, including molecular electrostatic potential surface, solvation free energy and radial distribution function analysis. This work will provide a fundamental guidance for the crystallization, separation, and purification of 1-naphthylamine.

Lattice Solvent Engineering Improves the Stability of a Cobalt Pyrenylnitronylnitroxide Ferrimagnetic Chain.

Reaction of 2-(1'-pyrenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (PyrNN) with [Co(hfac)2(H2O)2] (hfac = hexafluoroacetylacetonate) in n-heptane solvent (hep) with a small amount of bromoform (CHBr3 = bf) gives the 1D ferrimagnetic complex [Co(hfac)2PyrNN]n·0.5bf·0.5hep (Co-PyrNN·bf). This chain exhibits slow magnetic relaxation with magnetic blocking below 13.4 K, presenting a magnetic hysteresis with high coercive field (51 kOe at 5.0 K) as a hard magnet. It also shows frequency-dependent behavior consistent with one dominant relaxation process with an activation barrier of Δτ/kB = (365 ± 24) K. The compound is an isomorphous variant of a previously reported ambient unstable chain made by using chloroform (CHCl3 = cf), [Co(hfac)2PyrNN]n·0.5cf·0.5hep (Co-PyrNN·cf). This shows that the variation of a magnetically inactive lattice solvent can improve the stability of analogous, void space containing single-chain magnets.

High Lithium-Ion Conductivity, Halide-Coated, Ni-Rich NCM Improves Cycling Stability in Sulfide All-Solid-State Batteries

All-solid-state batteries attract significant attention owing to their potential to realize an energy storage system with higher safety and energy density. In this work, a halide electrolyte coating with high lithium-ion conductivity obtained by mechanical coating under n-heptane solvent and annealing at 200 °C of Ni-rich LiNi0.83Co0.14Mn0.03O2 (NCM) for Li6PS5Cl-type all-solid-state batteries is reported. A 10% Li3InCl6-coated NCM material was assembled into a 10% LIC@NCM/Li6PS5Cl/In all-solid-state battery with an initial charge capacity of 201.3 mAh g–1, a discharge specific capacity of 158.7 mAh g–1, and a Coulombic efficiency of 79.06%. After 100 cycles at room temperature at 0.1C current density, the capacity retention was 92% and the capacity retention was 72% after 270 cycles. In comparison, all-solid-state batteries using matched Li6PS5Cl and untreated NCM had a capacity retention rate of 53% after 100 cycles at 0.1C under the same charge/discharge regime and environment. It is indicated that the cycling performance and rate performance of the NCM material significantly improve after the 10% LIC coating. In this paper, X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), high-resolution high-resolution transmission electron microscopy (HR-TEM), scanning electron microscopy (SEM), and other tests and analyses confirmed the following: the pregenerated interfacial layer of approximately 2 nm on the surface of NCM after the 10% halide solid electrolyte coating improves the structural stability of the material during charging and discharging, the LIC coating layer slows down the decomposition of LI6PS5Cl during cycling, and the capacity increase at high rates is due to the reduction of the interfacial impedance between the cathode material and LI6PS5Cl solid electrolyte.

Supramolecular Incarceration and Extraction of Tetrafluoroberyllate from Water by Nanojars.

The previously unexplored noncovalent binding of the highly toxic tetrafluoroberyllate anion (BeF42-) and its extraction from water into organic solvents are presented. Nanojars resemble anion-binding proteins in that they also possess an inner anion binding pocket lined by a multitude of H-bond donors (OH groups), which wrap around the incarcerated anion and completely isolate it from the surrounding medium. The BeF4-binding propensity of [BeF4⊂{CuII(OH)(pz)}n]2- (pz = pyrazolate; n = 27-32) nanojars of different sizes is investigated using an array of techniques including mass spectrometry, paramagnetic 1H, 9Be, and 19F NMR spectroscopy, and X-ray crystallography, along with thermal stability studies in solution and chemical stability studies toward acidity and Ba2+ ions. The latter is found to be unable to precipitate the insoluble BaBeF4 from nanojar solutions, indicating a very strong binding of the BeF42- anion by nanojars. 9Be and 19F NMR spectroscopy allows for the unprecedented direct probing of the incarcerated anion in a nanojar and, along with 1H NMR studies, reveals the fluxional structure of nanojars and their inner anion-binding pockets. Single-crystal X-ray diffraction provides the crystal and molecular structures of (Bu4N)2[BeF4⊂{Cu(OH)(pz)}32], which contains a novel Cux-ring combination (x = 9 + 14 + 9), (Bu4N)2[BeF4⊂{Cu(OH)(pz)}8+14+9], and (Bu4N)2[BeF4⊂{Cu(OH)(pz)}6+12+10] and offers detailed structural parameters related to the supramolecular binding of BeF42- in these nanojars. The extraction of BeF42- from water into organic solvents, including the highly hydrophobic solvent n-heptane, demonstrates that nanojars are efficient binding and extracting agents not only for oxoanions but also for fluoroanions.

Recovery of paraffin from the filter cake used for paraffin decoloration in the Fischer-Tropsch synthetic process

The Fischer-Tropsch synthetic paraffin residue are mainly treated by combustion or landfill. In this study, an innovative process has been developed for the grading utilization of the Fischer-Tropsch synthetic paraffin residue by extraction and pyrolysis. Firstly, the Fischer-Tropsch synthetic paraffin residue was respectively extracted by n-pentane, n-hexane, n-heptane, cyclohexane and dichloromethane. The yield of extracted paraffin was related to solvent molecular weight and polarity, light alkanes were extracted more easily in non-polar solvents with relatively larger molecular weight. N-heptane showed the highest extraction yield of 57.86%, the extracted paraffin was similar to the paraffin product from Fischer-Tropsch and had more light components, less alkenes and oxygenated components. Afterwards, the solid residues after extraction were pyrolyzed at optimum conditions with 10 ℃/min and 500 ℃. The maximum yield of paraffin was up to 61.75% with the solvent of n-heptane in the grading utilization process, which accounted for 94.33% of the organic components in the Fischer-Tropsch synthetic paraffin residue. The recovered paraffin had higher saturation and less impurity than the Fischer-Tropsch paraffin. The solid product after pyrolysis had high specific surface area and could be processed into adsorbent and catalyst carrier. The grading technology could provide a rationalizing industrial scheme for handling the Fischer-Tropsch synthetic paraffin residue from the Shanxi Lu′an group corporation coal to oil plant of 1.0 million tons/a, 1852.5 tons of high-quality paraffin can be recovered each year.

Single-step integrated technology for enhanced CO2 biofixation and efficient lipid extraction in microalgal system including a water-immiscible solvent

The potential of microalgae for both carbon fixation and energy sustainability has been demonstrated. However, the low CO2 biofixation rate and high cost of lipid extraction restrict its large-scale development. This paper proposes a novel integrated technology for enhanced CO2 biofixation and efficient lipid extraction in microalgal system by adding water-immiscible solvent N-heptane over the culture medium. N-heptane can act as a ‘carbon sink’ and ‘extract agent’ without causing significant damage to microalgal cells. Specifically, N-heptane with the volume percentages of 4, 8, 12, 25 and 42 % was added to Chlorella sp. culture systems. Simulated flue gas containing 15 vol% CO2 in nitrogen gas was used as the sole carbon source. The maximum biomass concentration (0.84 g·L-1) and specific growth rate (0.23 d-1) were achieved with 12 % N-heptane. These values were higher than blank culture by 12.3 % (biomass concentration) and 56.9 % (specific growth rate). The CO2 biofixation rate increased with N-heptane to a maximum value of 220.2 mg·L-1·d-1, which was 64.7 % higher than that of the blank culture. Meanwhile, the system has a potential for the generation of biofuels with a maximum lipid amount of 2.82 g·gAlgae-1 in this single step approach.

A novel and facile semi-IPN system in fabrication of solvent resistant nano-filtration membranes for effective separation of dye contamination in water and organic solvents

Numerous studies have been conducted to design and develop solvent-resistant nano-filtration membranes. In this research, an Interpenetrating Polymer Network (IPN) system was used to obtain solvent-resistant membranes. For this purpose, hydroxyl-terminated polybutadiene (HTPB) and multifunctional isocyanate (MFI) were incorporated as additives into the polyphenylsulfone membrane matrix and the achieved semi-IPN structure caused dimensional stability and solvent resistance in membranes. The structure and morphology of the membranes were investigated using Attenuated Total Reflection-Fourier transform Infra-red (ATR-FTIR), Field emission scanning electron microscopy (FESEM), energy dispersive x-ray analysis (EDAX), elemental mapping, and atomic force microscopy (AFM). The thermal properties of the membranes were studied by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) and the mechanical properties were measured and the increase in tensile strength in compare of pure membrane was proved. The membranes showed excellent stability in acetone, n-heptane and dimethylformamide solvents. The performance of the membranes was evaluated by the pure water flux (PWF), contact angle, swelling degree, porosity assessment and dye rejection tests and the result showed that the PWF decreased with increasing HTPB percentage up to 40 wt% while their efficiency in removing methylene blue and methyl orange dyes was improved significantly due to reduced membrane pore size. The fabricated membranes were more resistant to fouling because of their hydrophilic nature.

Effect of adding graphene oxide on the structure and properties of needle coke

Using medium and low temperature coal tar pitch as raw material, the refined raw material is obtained by solvent extraction with a mixed solvent of n-heptane and toluene, and then different amounts of graphene oxide(GO) are added to the refined raw material for thermal polymerization and calcination to obtain needle coke. The composition of the raw materials was analyzed by element analysis, infrared spectroscopy (FT-IR), NMR, XPS and other detection methods, and the scanning electron microscope (SEM), X-ray diffractometer (XRD), polarizing microscope, electrochemical analysis and other methods were used to analyze the structure and electrochemical properties of different needle coke. The experimental results show that the mixed solvent of n-heptane and toluene can refine the raw materials, which can effectively enrich aromatics, optimize the composition of the raw materials, and effectively remove the heteroatoms in the raw materials. In particular, the removal effect of O and S atoms is particularly significant, and the removal rates are 25.21 % and 82.50 %, respectively. Adding 0.01 wt% of GO to the refined raw materials can obtain needle coke products with a regular layered structure and relatively good electrochemical performance.

Thermodynamic and structural description of relative solubility of the flavonoid rutin by DFT calculations and molecular dynamics simulations

Understanding the solubility of flavonoids is of relevance in view of the broad application such as antioxidant and antitumor agents. The solubility of flavonoid rutin has been experimentally investigated in a homologous series of alcohols, acetone, n-heptane and water solvents. In this work theoretical evaluation of Gibbs free energy of solvation was performed at the Density Functional Theory (DFT) and Molecular Dynamics (MD) levels, with the ωB97x-D functional and multistate Bennett acceptance ratio (MBAR) method, respectively. The degree of solubility of a given solute among various solvents is dictated by solute-solvent interactions, which may be represented by the solvation energy. Our calculated relative energy values due to solvent effects, using quantum chemical methods (PCM and SMD solvent models) do not follow strictly the observed solubility trend. However, the PCM model including solute-solvent dispersion interaction, solute-solvent repulsion interaction and solute cavitation energy contribution to the total energy (named DIS,REP,CAV) yielded an overall agreement with experimental solubility profile, with exception of ethanol solvent. A similar satisfactory accordance with experiment was found for MBresults, with a discrepancy also found for 1-butanol, which deserve further investigation. Analysis of spatial and radial distribution functions (SDF and RDF) for pure solvents and the analysis of the contributions of vdW and electrostatic terms for the total free energy reveal that a balance between dispersive and electrostatic interactions between the rutin and the solvent is necessary to solubilize the flavonoid, which corroborates with the values of these energy contributions to the solvation-free energy calculated by the MBAR method. The use of explicit solvent molecules in DFT calculations is precluded due to the size, flexibility, and many sites for solvent interactions of rutin molecule. Our results indicate that in general DFT-PCM (DIS,REP,CAV) and MBAR levels of calculations can satisfactorily predict the solvation free energy and solubility trend for flavonoid rutin along a series of solvents, and also provide a reasonable estimate of relative solubilities of other flavonoids, information that can be relevant for further molecular modeling studies.

Deasphalting of Atmospheric Iraqi Residue using Different Solvents

Different solvents (light naphtha, n-heptane, and n-hexane) are used to treat Iraqi Atmospheric oil residue by the deasphalting process. Oil residue from Al-Dura refinery with specific gravity 0.9705, API 14.9, and 0.5 wt. % sulfur content was used. Deasphalting oil (DAO) was examined on a laboratory scale by using solvents with different operation conditions (temperature, concentration of solvent, solvent to oil ratio, and duration time). This study investigates the effects of these parameters on asphaltene yield. The results show that an increase in temperature for all solvents increases the extraction of asphaltene yield. The higher reduction in asphaltene content is obtained with hexane solvent at operating conditions of (90 °C, 4/1 solvent to oil ratio), where the asphaltene yield was 93%. The highest recorded value of API value at 150 ml for all solvents at the highest temperature and duration time; this value is 32 when using n-heptane solvent at 15/1.

Preparation of Palladium Metal Intercalated between Graphite Layers with Low Palladium Loading for Cinnamaldehyde Hydrogenation

Abstract Spherical palladium nanoparticles between graphite layers were prepared by the intercalation of palladium chloride followed by its reduction between graphite layers. The palladium particles intercalated between graphite layers were more active for cinnamaldehyde hydrogenation to hydrocinnamaldehyde and hydrocinnamyl alcohol in n-heptane solvent than those supported on graphite surface.

Statistical analysis of operating variables for pseudo-emulsion hollow fiber strip dispersion technique: ethylparaben separation from aqueous feed stream

Ethylparaben (EP) is a member of parabens family which are the esters of p-hydroxybenzoic acid possessing anti-microbial and anti-fungal properties. But studies have pointed towards their endocrine disrupting prospective. Their large consumption as preservatives have made it possible for them to enter in the aquatic streams. In spite of their considerable removal in wastewater treatment plants, parabens are still detected in extremely small amounts in aqueous streams which could be harmful to the aquatic life. EP exists in the range of 0.3–1600 ng/L in aquatic streams like river water, influent and effluent of wastewater treatment plant. So comprehensive investigation were carried out using pseudo-emulsion hollow fiber strip dispersion (PEHFSD) technique with pseudo-emulsion consisting of trioctylamine (carrier), n-heptane (solvent) and sodium carbonate (stripping phase) for the removal of EP from aqueous solution. In this study, emphasis has been given to the use of full factorial design for the optimization of several operational variables like concentration of feed, carrier and stripping phase for EP removal. Statistical analysis of variance was examined to find out the importance of every factor. Interaction plot was used to study the interdependence between the factors and their combined influence on the %extraction of EP. Contour plots provided the optimum concentration range for the maximum EP extraction and 100% removal was achieved by PEHFSD technique at optimum conditions. The mass transfer coefficients were evaluated at optimal conditions.

Application of hydrophobic ionic liquid [Bmmim][PF6] in solvent extraction for oily sludge

Abstract In this study, an ionic liquid (IL), 1-butyl-2,3-dimmmethylimidazolium hexafluorophosphate ([Bmmim][PF6]), was used in combination with a composite solvent of methyl acetate and n-heptane to enhance the oil extraction from oily sludge. The oil recovery increased by approximately 15% compared with that of solvent extraction without [Bmmim][PF6] at the optimal ratios of IL to sludge and solvents to sludge, which were at 2:5 (M/M) and 4:1 (V/M), respectively. The saturate, aromatic, resin and asphaltene (SARA) analysis revealed that the recovery of resins and asphaltenes was increased by 14% and 38%, respectively, in the solvent extraction with the addition of [Bmmim][PF6]. [Bmmim][PF6] maintained a good performance after its reuse four times. The addition of [Bmmim][PF6] changed the adhesion forces between oil and soil. The IL-assisted solvent extraction procedure followed the pseudo second-order kinetic model, while the unassisted solvent extraction procedure followed the pseudo first-order kinetic model. The results also demonstrated that [Bmmim][PF6] decreased the solvent consumption by approximately 60% each time. Additionally, [Bmmim][PF6] can be easily separated. The results suggested that enhancing the solvent extraction with this IL is a promising way to recover oil from oily sludge with a higher oil recovery rate and lower organic solvent consumption than those with the unassisted solvent extraction method.

Effects of solvents on the excited state intramolecular proton transfer and hydrogen bond mechanisms of alizarin and its isomers

In this paper, we use time-dependent density functional theory (TD-DFT) to investigate the effects of protic and aprotic solvents on the excited state intramolecular proton transfer (ESIPT) and hydrogen bond (ESHB) mechanisms of the alizarin. The calculation results show that there are mainly two forms of alizarin: alizarin-A and alizarin-B (both are isomers), in which alizarin-A is more stable than alizarin-B. In the aprotic (dimethylsulfoxide and n-heptane) solvents, alizarin-A is more prone to proton transfer reactions than alizarin-B in the excited state. In protic (methanol) solvent, the ESIPT process of alizarin-A is carried out without energy potential barrier, while the energy potential barrier of alizarin-B is only 0.04 kcal/mol, which is easier to occur than in aprotic solvent conditions. The scatter plot and isosurface of the reduced density gradient function indicate that the ESHB of alizarin in the protic solvent is stronger than the aprotic solvent. In other words, the hydroxyl group at the proton transfer site undergoes more hydrogen bonding interactions in the protic solvent, which will facilitate the occurrence of the ESIPT process. In general, our work will contribute to regulate the ESIPT process of alizarin and its derivatives through solvent effects in the future, as well as application to more fields.

Characterization and stability study of pseudo-emulsion hollow fiber membrane: Separation of Ethylparaben

Ethylparaben (EP), being one of the members of parabens family is an endocrine disrupting compound. Despite their efficient elimination in waste water treatment plants, parabens are still noticed in river waters. Studies were conducted by Pseudo-emulsion hollow fiber strip dispersion (PEHFSD) system using pseudo-emulsion comprised of Trioctylamine (carrier), n-heptane (solvent) and Na2CO3 (strippant) for EP elimination from aqueous feed phase. Influence of different operational factors like concentration of feed, carrier and stripping phase were studied for EP removal. 100% removal of EP was achieved by PEHFSD system. Permeability studies were conducted and mass transfer coefficient for aqueous and membrane phase were also evaluated at optimum conditions. Fourier transform infrared spectroscopy confirmed the bonding and existence of various functional groups in the membrane phase. Field emission scanning electron microscope revealed the pores on hollow fiber membrane surface. Droplet size distribution and backscattering profile of pseudo-emulsion at different impeller speed indicated instability of pseudo-emulsion and concentrated EP can be easily recovered. Multiple runs conducted with fresh feed solution and fresh pseudo-emulsion showed 100% removal of EP for five runs which indicated stability of membrane phase within the micropores for longer time. The recyclability of pseudo-emulsion phase was also studied by contacting the fresh feed with the previously used pseudo-emulsion phase. It was observed that removal of EP was 100%, 73% and 43% for 1st, 2nd and 3rd run respectively.

Speciation of sulphur in asphaltenes and resins from Argentinian petroleum by using XANES spectroscopy

Argentinian crude oil samples from different origins have been processed to separate in the four fractions Saturates, Aromatics, Resins, and Asphaltenes (SARA). Asphaltene and resin fractions were extracted using n-pentane and n-heptane as precipitating solvents. Sulphur contents of the samples were determined by elemental analysis and X-ray Absorption Spectroscopy at the Sulphur K-edge was used to perform sulphur speciation for resin and asphaltene fractions. Reduce sulphur as sulphides, disulphides and thiophenes dominate the spectra of asphaltenes, resins I and crude oils samples. A higher abundance of sulfoxide forms were found in the resin II fraction. In addition, it was found that the asphaltenes are more enriched in aromatic sulphur (thiophene) when the n-heptane solvent is employed. From the sulphur speciation determination it was possible to incorporate different sulphur forms in the hypothetical average molecular structures for the Argentinian asphaltenes.

Elucidation of the Average Molecular Structure of Argentinian Asphaltenes

Petroleum asphaltenes were separated from three different Argentinian crude oils. The asphaltene fractions were extracted by precipitation employing n-pentane and n-heptane solvents, and the coprec...

Synthesis Of 4-Alil-6- (Hydroxymethyl) -2-Methody Phenol Compounds from Eugenol Through Mannich Reaction Followed Methylation with Methyl Iodide and Subtitution Using NaOH

Eugenol derivative compound 4-allyl-6-hydroxymethyl-2-methoxy phenol was synthesized through Mannich reaction, methylation, dan nucleophilic substitution. Mannich reaction was carried out by reacting eugenol, formaldehyde 37%, and dimethylamine 40 % in reflux condition with n-heptane solvent at temperature 98o-100oC for 10 hours produced 4-allyl-6-(dimethylamino)methyl-2-methoxy phenol with yield of 83 %. The formation of dimethylaminomethyl group supported by C-N stretching vibration at 1246,16 cm-1 and ion molecule peak at 221 in GC-MS analysis. Methylation of 4-allyl-6-(dimethylamino)methyl-2-methoxy phenol was carried out with methyl iodide in ethanol solvent produced 6-((N-iodo-N-methyl-N-methyl-N-methylamino) methyl)-4-allyl-2-methoxy phenol in solid form, which then purified by recrystallization with 78,15 % yield. 4-allyl-6-(hydroxymethyl)-2-methoxy phenol was synthesized by nucleophilic substitution reaction of 6-((N-iodo-N-methyl-N-methyl-N-methylamino)methyl)-4-allyl-2-methoxy phenol with sodium hydroxide in reflux condition then purified by coloum chromatography gave liquid compound with yield of 65,05%. The formation of hydroxymethyl group supported by OH vibration at 3433,9 cm-1 and ion molecule peak at 194 in GC-MS analysis show the relative molecular mass of synthesized product.

Liquid-liquid equilibria of n-heptane, methanol and deep eutectic solvents composed of carboxylic acid and monocyclic terpenes

Driven by the absence of quaternary LLE data for systems containing deep eutectic solvents (DES), phase equilibrium data has been determined for systems composed of n-heptane, methanol, and hydrophobic DES. Three DES were studied; levulinic acid was used as hydrogen bond acceptor (HBA) and L-menthol, thymol and carvacrol were used as hydrogen bond donors (HBDs). It is a commonly used assumption that the ratio of HBA and HBD is the same as the initial DES composition and equal in both phases. However, it was shown that the ratio of HBD and HBA is not constant and changes with initial concentration of the eutectic mixture in the system. Carvacrol- and thymol-based systems show a larger miscibility gap than L-menthol-based systems. This is caused by stronger HBD-HBA interactions of thymol-levulinic acid and carvacrol-levulinic acid which keep a larger fraction of the DES constituents together in the lower phase than in the L-menthol-levulinic acid-based systems. The investigated systems are promising candidates for separation technologies where high solubility of target compounds is desired in both liquid phases, as in centrifugal partition chromatography, for example.

Reverse osmosis separation of particular organic solvent mixtures by a perfluorodioxole copolymer membrane

Reverse osmosis (RO) separation of organic solvent mixtures where solvent molecular weights are < 100 Da is challenging especially for powerful solvents that swell most uncrosslinked polymers. To avoid polymer swelling by solvents, a particular perfluoropolymer, perfluoro-2,2-dimethyl-1,3-dioxole copolymerized with tetrafluoroethylene, (PDD-TFE), designated CMS-7, was studied. This amorphous glassy extremely hydrophobic copolymer has a very high free volume (FV) fraction. The maximum dimension of FV regions is less than ~ 0.65 nm allowing only single solvent molecule permeation. Further, interactions between polarity, dimensions and shapes of solvent molecules with those of polymer FV elements can lead to extraordinarily selective permeation. RO separation of the following binary systems through a thin 1.67 µm film of this polymer supported on an e-PTFE support was studied over 1000–3500 kPa feed pressure: N-Methyl-2-pyrrolidone (NMP)-toluene; dimethylformamide (DMF)-toluene; dimethylsulfoxide (DMSO)-toluene; NMP-methanol; n-butanol-ethanol. Pure toluene appeared as permeate for three polar aprotic-aromatic systems from highly toluene-rich feeds; the membrane rejected polar molecules having dimensions similar to those of toluene. High osmotic pressure of the feed mixtures employed vis-à-vis feed pressures used reduced toluene permeation flux and the range of separable feed mixtures. Pure methanol permeate was obtained from particular polar aprotic-polar protic NMP-methanol mixtures due to significantly smaller methanol dimensions. Pure ethanol permeate was also similarly obtained from a particular mixture with n-butanol, a case of polar protic1-polar protic2 system where ethanol molecules were smaller. Such novel and clean-cut pressure-driven separations may be due to various combinations of the dimensions of the solvent molecules and the polymer FV regions, high polymer hydrophobicity, polarity of the aprotic/protic solvents and very low swelling of the polymer. Solvent sorption studies of dense polymers provide an insight into swelling of the polymer by the solvent and potential solvent-specific interactions. Sorption studies using 25 µm polymer samples for polar aprotic solvents, NMP, DMF, DMSO, yielded very low levels of sorption, 0.4–0.9 wt%; those for toluene and methanol were already known to be only 1.34 and 1.2 wt% respectively. Permeation behaviors of other solvent mixtures, toluene-n-heptane, NMP-tetrahydrofuran, methanol-water, ethanol-water as well as individual phases of the immiscible mixture of NMP and the nonpolar solvent n-heptane were also studied. To improve understanding, permeation of pure water in reverse osmosis mode was also investigated.