Poly Ethylene Glycol Dimethyl Ether Research Articles

Phase Diagrams for Liquid−Liquid and Liquid−Solid Equilibrium of the Ternary Poly(ethylene glycol) Dimethyl Ether 2000 + Sodium Carbonate + Water System

The complete phase diagram for the poly(ethylene glycol) dimethyl ether 2000 (PEGDME2000) + Na2CO3 + H2O system at 298.15 K was determined. Experimental liquid−liquid equilibrium phase diagrams, tie lines, and plait points were obtained for the ternary system. Compositions of the liquid−liquid and the liquid−liquid−solid equilibria were determined from calibration curves of refractive index of the solutions, and atomic absorption (AA) and X-ray diffraction analyses were made on the solids. Binodal curves were described using the Merchuk equation at T = (288.15, 293.15, 298.15, 308.15, and 318.15) K, and the fitting parameters were obtained for the corresponding temperatures. The effects of temperature on the binodal curve were also studied, and it was observed that the area of the biphasic region increased slightly with increase in temperature. Also, the tie lines were fitted to both the Othmer−Tobias and Bancroft and Setschenow-type equations. Correlation coefficients for all equations are reported.

Solubility of CO 2 in CO 2-philic oligomers; COSMOtherm predictions and experimental results

We report the solubility of carbon dioxide in four physical solvents and compare our data to predicted phase behavior using the conductor-like screening model for real solvents (COSMO-RS) formalism. The solubility data are presented in pressure-composition ( Px) diagrams as well as Henry's law coefficients on a wt% basis at 298.15 K. The oligomers presented in this study are poly ethylene glycol di-methyl ether (PEGDME), perfluoro polyether (PFPE), poly di-methyl siloxane (PDMS), and poly propylene glycol di-methyl ether (PPGDME), which is a new solvent designed for this application by our group. These oligomers had 2–5 repeat units. We assess these four oligomers for capturing CO 2 from high-pressure streams. The COSMO-RS formalism is able to qualitatively and to some extent quantitatively describe solubilities of CO 2 in each of the oligomers.

Cytotoxicity of cis-platinum(II) cycloaliphatic amidine complexes: Ring size and solvent effects on the biological activity

A series of new platinum(II) amidine derivatives of the type cis-[PtCl(2){Z-NHC(NHR)Me}(2)] (R=cyclopropyl, 1; cyclopentyl, 2; cyclohexyl, 3) were prepared in high yield by addition of the corresponding cyclic aliphatic amine RNH(2) to the coordinated acetonitrile ligands in cis-[PtCl(2)(NCMe)(2)]. The solution behaviour of 1-3 has been studied in DMSO, PEG 400 (polyethylene glycol) and PEG-DME 500 (polyethylene glycol dimethylether). The amidine complexes 1-3 were evaluated for their cytotoxic properties against a panel of human tumor cell lines containing examples of cervix (HeLa), breast (MCF7), lung (A549) and colon (HCT-15) cancer. Moreover, the amidine complexes were tested for their cytotoxicity against normal human fibroblasts (HFF-1). For comparison purposes, the cytotoxicity of cisplatin was examined under the same experimental conditions. The results obtained showed that PEG and PEG-DME behave as good solvents to carry out biological assays with platinum complexes which are water-insoluble and unstable in DMSO. Complexes 2 and 3 exhibited a biological activity comparable to that of cisplatin.

Flow Pattern, Pressure Drop, and Mass Transfer in a Gas−Liquid Concurrent Two-Phase Flow Microchannel Reactor

Flow pattern, pressure drop, and mass transfer characteristics have been studied for the gas−liquid two-phase flow in a 1.0 mm inner diameter circular microchannel reactor. A mixture of CO2, N2, and polyethylene glycol dimethyl ether was used to represent the gas and liquid phases, respectively. Bubbly, slug, churn, and slug-annular flow patterns were observed in the present work. A flow pattern map using superficial gas and liquid velocities as coordinates has been developed and compared to the existing flow pattern maps for ∼1 mm diameter channels. The data obtained for the pressure drop of the two-phase flow were analyzed and compared with the homogeneous model and the separate flow model to assess their predictive capabilities. The liquid side volumetric mass transfer coefficient increased with an increase of the superficial gas and liquid velocities, and the influences of the superficial gas and liquid velocities on it were demonstrated. The liquid side mass transfer coefficient, which was as high as...

Liquid−Liquid and Liquid−Liquid−Solid Equilibrium of the Poly(ethylene glycol) Dimethyl Ether 2000 + Sodium Sulfate + Water System

The phase diagram for the poly(ethylene glycol) dimethyl ether (PEGDE) + Na2SO4 + H2O system at 298.15 K using PEGDE with a molar mass of 2000 was determined. Compositions of the liquid−liquid and the liquid−liquid−solid equilibria were determined using calibration curves of refractive index of the solutions, and atomic absorption (AA) and X-ray diffraction analyses were made on the solids. The solid phase in equilibrium with the biphasic region was anhydrous Na2SO4. An empirical nonlinear three-parameter expression developed by Merchuk was used for reproducing the experimental binodal data at T = (288.15, 298.15, 308.15, and 318.15) K, and the fitting parameters were obtained for the corresponding temperatures. The effects of temperature on the binodal curve were also studied, and it was observed that the area of the biphasic region increased slightly with an increase in temperature. The experimental tie-line compositions at the aforementioned temperatures were fitted to both the Othmer−Tobias and Bancroft and Setschenow-type equations. Correlation coefficients for all equations are reported.

Plastic–polymer composite electrolytes: Novel soft matter electrolytes for rechargeable lithium batteries

We present here a soft matter solid composite electrolyte obtained by inclusion of a polymer in a semi-solid organic plastic lithium salt electrolyte. Compared to lithium bis-trifluoromethanesulfonimide-succinonitrile (LiTFSI-SN), the (100 − x)%-[LiTFSI-SN]: x%-P (P: polyacrylonitrile (PAN), polyethylene oxide (PEO), polyethylene glycol dimethyl ether (PEG)) composites possess higher ambient temperature ionic conductivity, higher mechanical strength and wider electrochemical window. At 25 °C, ionic conductivity of 95%-[0.4 M LiTFSI-SN]: 5%-PAN was 1.3 × 10 −3 Ω −1 cm −1 which was twice that of LiTFSI-SN. The Young’s modulus ( Y) increased from Y → 0 for LiTFSI-SN to a maximum ∼1.0 MPa for (100 − x)%-[0.4 M LiTFSI-SN]: x%-PAN samples. The electrochemical voltage window for composites was approximately 5 V (Li/Li +). Excellent galvanostatic charge/discharge cycling performance was obtained with composite electrolytes in Li|LiFePO 4 cells without any separator.

Rechargeable Li/LiFePO 4 cells using N-methyl- N-butyl pyrrolidinium bis(trifluoromethane sulfonyl)imide–LiTFSI electrolyte incorporating polymer additives

We have incorporated polymer additives such as poly(ethylene glycol) dimethyl ether (PEGDME) and tetra(ethylene glycol) dimethyl ether (TEGDME) into N-methyl- N-butylpyrrolidinium bis(trifluoromethane sulfonyl)imide (PYR 14TFSI)–LiTFSI mixtures. The resulting PYR 14TFSI + LiTFSI + polymer additive ternary electrolyte exhibited relatively high ionic conductivity as well as remarkably low viscosity over a wide temperature range compared to the PYR 14TFSI + LiTFSI binary electrolytes. The charge/discharge cyclability of Li/LiFePO 4 cells containing the ternary electrolytes was investigated. We found that Li/PYR 14TFSI + LiTFSI + PEGDME (or TEGDME)/LiFePO 4 cells containing the two different polymer additives showed very similar discharge capacity behavior, with very stable cyclability at room temperature (RT). Li/PYR 14TFSI + LiTFSI + TEGDME/LiFePO 4 cells can deliver about 127 mAh/g of LiFePO 4 (74.7% of theoretical capacity) at 0.054 mA/cm 2 (0.2C rate) at RT and about 108 mAh/g of LiFePO 4 (63.4% of theoretical capacity) at 0.023 mA/cm 2 (0.1C rate) at −1 °C for the first discharge. The cell exhibited a capacity fading rate of approximately 0.09–0.15% per cycle over 50 cycles at RT. Consequently, the PYR 14TFSI + LiTFSI + polymer additive ternary mixture is a promising electrolyte for cells using lithium metal electrodes such as the Li/LiFePO 4 cell reported here. These cells showed the capability of operating over a significant temperature range (∼0–∼30 °C).

Solubilities of Carbon Dioxide in Polyethylene Glycol Ethers

New extensive data are reported for the solubility of carbon dioxide in fourteen physical solvents, and compared to two other solvents widely used in industry (selexol® and sulfolane). The solubility data are expressed by Henry's law constants and have been measured at 25 °C, 40 °C and 60 °C, using an Autoclave cell. The study concludes that polyethylene glycol dimethyl ethers, and mixtures of these solvents are the best solvents for CO2 removal.

Excess molar volume and viscosity deviation for binary mixtures of polyethylene glycol dimethyl ether 250 with 1,2-alkanediols (C 3–C 6) at T = (293.15 to 323.15) K

In this work, density and viscosity have been determined for (polyethylene glycol dimethyl ether 250 + 1,2-propanediol, or 1,2-butanediol, or 1,2-pentanediol, or 1,2-hexanediol) binary systems over the whole concentration range at temperatures of (293.15, 303.15, 313.15, 323.15) K and atmospheric pressure. Experimental data of mixtures were used to calculate the excess molar volumes V E, and viscosity deviations Δ η. These results were fitted by the Redlich–Kister polynomial relation to obtain the coefficients and standard deviations.

N-Methyl-( n-butyl)pyrrolidinium bis(trifluoromethanesulfonyl)imide-LiTFSI–poly(ethylene glycol) dimethyl ether mixture as a Li/S cell electrolyte

We have characterized a ternary mixture of N-methyl-( n-butyl)pyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR 14TFSI) + 0.5 M LiTFSI + y poly(ethylene glycol) dimethyl ether (PEGDME) ( y = kg PEGDME/kg PYR 14TFSI) as an electrolyte in Li metal/S cells. The presence of PYR 14TFSI in the mixture resulted in a significant improvement of the thermal stability and the ionic conductivity ( σ) of the mixture with increasing PEGDME contents (for example, σ = 4.2 × 10 −3 S cm −1 at 29 °C for y = 2.0). These improvements are most significant at low temperatures, which is probably due to a lowering of the viscosity of the mixture with higher amounts of PEGDME. It is found that the mixture has good compatibility with respect to Li metal as demonstrated by time-dependent interfacial impedance and galvanostatic Li stripping/deposition measurements. We found that a Li/S cell with PYR 14TFSI + 0.5 M LiTFSI + y PEGDME ( y = 2.0) can deliver about 1300 mAh g −1-sulfur at 0.054 mA cm −2 at ambient temperature at the first cycle. A better charge/discharge cyclability of the Li/S cell in PYR 14TFSI + 0.5 M LiTFSI + y PEGDME was found at higher PEGDME contents, and a Li/S cell with the mixture having y = 2.0 exhibited a capacity fading rate of 0.42% per cycle over 100 cycles at 0.054 mA cm −2 at 40 °C. Consequently the PYR 14TFSI + LiTFSI + PEGDME mixture is a promising electrolyte for Li/S cells.

Ionic conductivity and morphology of semi‐interpenetrating‐type polymer electrolyte entrapping poly(siloxane‐g‐allyl cyanide)

AbstractWe prepared a semi‐IPN (interpenetrating network)‐type solid polymer electrolyte (SPE) using poly (ethylene glycol)dimethacrylate (PEGDMA) as a polymer matrix containing a monocomb‐type poly(siloxane‐g‐allyl cyanide) and poly(ethylene glycol)dimethylether (PEGDME) for the lithium secondary battery. The poly(siloxane‐g‐allyl cyanide)s were prepared by a hydrosilation reaction of poly (methyl hydrosiloxane) with allyl cyanide and characterized by 1H NMR and FTIR. The semi‐IPN‐type electrolyte was prepared by thermal curing, and conductivities of samples were measured by impedance spectroscopy using an indium tin oxide (ITO) electrode. The ionic conductivity of the semi‐IPN‐polymer electrolyte was about 1.05 × 10−5 S cm−1 with 60 wt % of the poly(siloxane‐g‐allyl cyanide) and 6.96 × 10−4 S cm−1 with 50 wt % of the PEGDME and 10 wt % of the poly(siloxane‐g‐allyl cyanide) at 30°C. The SEM morphology of the cross section of the semi‐IPN‐polymer electrolyte film was changed from discontinuous network to continuous network as increasing the PEGDME content and decreasing the poly(siloxane‐g‐allyl cyanide) content. The mechanical stability was also enhanced when increasing the PEGDME content. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Preparation and characterization of porous polysucrose microspheres

A set of novel porous polysucrose microspheres were prepared by the inverse suspension polymerization using soluble polysucrose, epichlorohydrin (EP) as crosslinker and dimethyl ether of polyethylene glycol (DMPE) as porogen. The fourier transform infrared spectrometer (FTIR), optical microscope (OM), scanning electronic microscope (SEM) and laser diffraction method were utilized to characterize the structure and morphology of the porous microspheres. The results indicated that these beads had spherical shape with the mean particle size of around 340 μm, narrow distribution, and porous structure. The equilibrium water contents of these porous microspheres ranged from 92.1% to 96.6% with the increasing contents of porogen. The porosities ranged from 82.3% to 90.3% with the increasing hydroxyl contents from 19.3 to 21.8 mmol/g, and bovine serum albumin (BSA) was used as adsorbate model to examine the adsorption behavior of the porous microspheres. The saturated adsorption capacities of these microspheres ranged from 42.6 to 98.5 mg/g.

New crosslinking agent as a Lewis acid for solid polymer electrolytes

Poly(ethylene glycol) borate acrylate (PEGBA) was synthesized as a new crosslinking agent for solid polymer electrolyte (SPE) based on non-woven matrix. It has not only three crosslinkable acrylate groups for higher crosslinking density, but also Lewis acid center acting as an anion receptor. The ionic conductivity of SPE containing 15 wt.% PEGBA reached 5.5 × 10 −4 S cm −1, because the content of non-volatile plasticizer, poly(ethylene glycol) dimethyl ether (PEGDME), could be increased to 85 wt.% without leakage. In addition, its transference number and electrochemical stability were also enhanced to 0.37 and 5.2 V, respectively, due to the presence of Lewis acid center in PEGBA.

Nanostructured nickel sulfide synthesized via a polyol route as a cathode material for the rechargeable lithium battery

Nanostructured nickel sulfide (NiS) was synthesized via a simple polyol route. The NiS powders were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and electrochemical testing. The results revealed that the cycle life of the annealed NiS sample was improved over that of the as-prepared sample. The electrochemical performance was also tested using 1 M lithium trifluoromethanesulfonimide (LiTFSI) in a solvent of poly(ethylene glycol) dimethyl ether (PEGDME) in order to compare with a sample tested in the conventional electrolyte of 1 M LiPF 6 in a mixture of ethylene carbonate (EC) and dimethyl carbonate (DMC). The results showed that the electrochemical properties were improved by using the 1 M LiTFSI/PEGDME electrolyte.

Polymer electrolytes based on poly(ethylene glycol) dimethyl ether and the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate: Preparation, physico-chemical characterization, and theoretical study

Polymer electrolytes based on poly(ethylene glycol) dimethyl ether (PEGdME) and the ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF 6) have been prepared and characterized by different techniques. Coordination of the IL by the polymer occurs mainly in the amorphous phase. This finding was correlated with previous theoretical investigations of a similar model for polymer electrolytes based on poly(ethylene oxide), PEO, and IL. It has been obtained ionic conductivity σ ∼ 10 −3 S cm −1 for the polymer electrolyte with 35 wt% of IL at 100 °C. The same order of magnitude for σ was obtained by molecular dynamics simulation of PEO/IL. This work demonstrates consistency between experimental and theoretical results for polymer electrolytes containing ionic liquids.

Volumetric Properties, Viscosities, Refractive Indices, and Surface Tensions for Aqueous Genosorb 1753 Solutions

The densities and viscosities of aqueous solutions of Genosorb 1753 (Selexol) were measured in the range (298.15 to 343.15) K. Refractive indices in the range (293.15 to 333.15) K and surface tensions in the range (298.15 to 323.15) K were also measured. Genosorb 1753 is a widely used physical solvent, a mixture of polyethylene glycol dimethyl ethers. All the experimental data were correlated using polynomials as a function of the temperature and concentration.

Chemical Structures of Liquid Poly(ethylene glycol)s with Different End Groups at Buried Polymer Interfaces

The interfacial conformational behaviors or structure of liquid poly(ethylene glycol)s (PEGs) with different end groups in contact with solid polymers of different hydrophobicities were investigated by sum frequency generation (SFG) vibrational spectroscopy. The solids at the interface included deuterated poly(methyl methacrylate) (d-PMMA), deuterated polystyrene (d-PS), deuterated polyethylene (d-PE), and a fluorinated polymer AF-2400; the liquids were poly(ethylene glycol) diol (PEGD), poly(ethylene glycol) methyl ether (PEGME), and poly(ethylene glycol) dimethyl ether (PEGDME). For comparison purposes, SFG has also been used to study PEG surfaces in air and in contact with fused silica. Depending on the hydrophobicity of the solid polymer, the hydroxyl O−H and methoxy OCH3 end groups and ethoxy OCH2 backbone groups of the liquid PEGs exhibited different interfacial behavior, which can be correlated to molecular interactions at these interfaces. The favorable interaction between the hydrophobic solids and the hydrophobic functional groups of the liquid PEGs causes the OCH3 end groups, and to some extent the OCH2 groups of the backbone, to become strongly ordered at the solid polymer/liquid polymer interface. We have shown that the end groups of the liquid PEGs, although comprising a small proportion of the total molecule, actually can dominate the interfacial behavior of the liquid polymer.

Zinc ion conducting polymer electrolytes based on oligomeric polyether/PVDF-HFP blends

Here we report novel zinc ion conducting polymer electrolytes based on oligomeric polyether/PVDF-HFP blends with or without the incorporation of a small amount of organic carbonates. Their thermal properties, ionic conductivity and electrochemical properties are characterized and the effect of different Zn salts and incorporation of a small amount of organic carbonates are investigated. These polymer electrolyte membranes exhibit essentially no or very low volatility, high thermal stability, high ionic conductivity, wide electrochemical stability window, acceptable interfacial resistance with zinc, and the capability for reversible Zn plating/stripping. Particularly promising are electrolyte systems based on the combination of low lattice energy zinc imide salt and a special co-solvent of oligomeric poly(ethylene glycol) dimethyl ether (PEGDME) mixed with a small amount of ethylene carbonate (EC), dimensionally stabilized with PVDF-HFP. Such novel polymer electrolyte membranes could lead to the development of new kinds of electrochemical energy storage devices based on zinc electrochemistry, including solid-state, thin-film rechargeable zinc/air cells envisaged.

Ionic Transport and Interfacial Stability of Sulfonate-Modified Fumed Silicas as Nanocomposite Electrolytes

Degussa A200 and R711 fumed silica surfaces were modified by attaching lithium sulfonate groups through alkyl or oligomer chains, respectively, in an attempt to form single-ion conducting fumed silicas: A200-lithium propanesulfonate (A200-LiPS), R711-poly(lithium vinylsulfonate) (R711-pLiVS), and R711-poly(lithium 2-acrylamido-2-methyl-1-propanesulfonate) (R711-pLiAMPS). Conductivity, lithium transference number, and Li/electrolyte interfacial stability measurements were conducted on nanocomposite electrolytes prepared by dispersing the conducting fumed silicas into solvents consisting of oligomeric polyethylene glycol dimethyl ether (PEGdm), polyethylene oxide (PEO), or PEGdm/PEO blends. Among the three sulfonate-modified fumed silicas, the highest conductivity was always obtained using R711-pLiAMPS. Adding lithium salts to the solvent, such as lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), lithium bis(perfluoroethylenesulfonyl)imide (LiBETI), lithium bis(oxalato)borate (LiBOB), and lithium phosphate (Li3PO4), increases room-temperature conductivity and interfacial stability while maintaining relatively high lithium transference numbers.

Highly ion-conductive solid polymer electrolytes based on polyethylene non-woven matrix

Highly ion-conductive solid polymer electrolyte (SPE) based on polyethylene (PE) non-woven matrix is prepared by filling poly(ethylene glycol) (PEG)-based crosslinked electrolyte inside the pores of the non-woven matrix. The PE non-woven matrix not only shows good mechanical strength for SPE to be a free-standing film, but also has very porous structure for high ion conductivity. The ion conductivity of SPE based on PE non-woven matrix can be enhanced by adding sufficient non-volatile plasticizer such as poly(ethylene glycol) dimethyl ether (PEGDME) into ion conduction phase without sacrificing mechanical strength. SPE with 20 wt.% crosslinking agent and 80 wt.% non-volatile plasticizer shows 3.1 × 10 −4 S cm −1 at room temperature (20 °C), to our knowledge, which is the highest level for SPEs. It is also electrochemically stable up to 5.2 V and has high transference number about 0.52 due to the introduction of anion receptor as an additive. The interfacial resistance between Li electrode and SPE is low enough to perform charge/discharge test of unit cell consisting of LiCoO 2/SPE/Li at room temperature. The discharge capacity of the unit cell shows 87% of theoretical value with 86% Coulombic efficiency.