Ternary complexes of neodymium(III) and samarium(III) picrate triethylene glycol: structural, spectroscopic, and photoluminescent properties

The ternary complexation of neodymium(III) and samarium(III) with triethylene glycol (EO3) and picrate anion (Pic) were characterized by elemental analyses, FTIR (Fourier-transform infrared) spectroscopy, single crystal X-ray diffraction, and photoluminescence (PL). Both the [Nd(Pic)(H₂O)₂(NO₃)(EO3)](Pic) and [Sm(Pic)(H₂O)₂(NO₃)(EO3)](Pic)·H₂O complexes were isostructural with a ten-coordination number. In both complexes, the picrate and nitrate anions were coordinated to Ln(III) in a bidentate manner, and with the the EO3 ligand in a tetradentate manner, the addition of two water molecules maintained a ten-coordination number. The lighter lanthanide-picrate complexes formed a ten-coordination number due to the lanthanide contraction effect, acyclic polyether chain length, and number of donor oxygen atoms. The acyclic EO3 ligand affected photoluminescent intensity and its conformation on the structure of the [Ln(Pic)(NO₃)(H₂O)₂(EO3)]⁺ moiety. Photoluminescent measurement showed complex Nd(III) emissions at 403, 486, and 682?nm, with the strongest emission peak at 403?nm. Formation of these peaks occurred due to the intraligand π–π transitions of the Pic anion. The Sm(III) complex exhibited the emission characteristic of the Sm(III) ion in the red spectral region at 616.7?nm (⁴G_5/2 → ⁶H_9/2 transition), even though the ligand emissions were also observed in the PL spectrum. The emission intensity of the 4f–4f transitions in the Sm complex was significantly higher than that found in its salt. We noted that the [Sm(Pic)(H₂O)₂(NO₃)(EO3)](Pic)·H₂O complex was an excellent red-light-emitter and would be considered as a candidate material for organic light emitting diodes.     

Thermodynamics of dissolution of thiourea in triethylene glycol

The solubility of thiourea in triethylene glycol was determined in the temperature range of 318.35–357.75 K. The experimental data were approximated by the modified Apelblat equation. The dissolution enthalpy and dissolution entropy were calculated from the experimental data. The mutual interactions between solvent and solute were discussed in brief. The obtained data may be useful for development of the processes involving thiourea.     

Postradiation copolymerization of N-vinylpyrrolidone with triethylene glycol dimethacrylate

The kinetics of low-temperature postradiation copolymerization of N-vinylpyrrolidone (N-VP) with triethylene glycol dimethacrylate (TGM-3) were studied using reactant mixtures with different compositions and different pre-irradiation doses, and the characteristics of the obtained copolymers were determined. The copolymerization process is most effective in glassy systems (at an N-VP concentration in solution below 80 mol %). It was shown that a poly-N-vinylpyrrolidone homopolymer is formed along with a crosslinked N-VP-TGM-3 copolymer.     

Analyzing solubility of acid gas and light alkanes in triethylene glycol

Physical solvents such as ethylene glycol （EG）, diethylene glycol （DEG）, and triethylene glycol （TEG） are commonly used in wet gas dehydration processes with TEG being the most popular due to ease of regeneration and low solvent losses. Unfortunately, TEG absorbs significantly more hydrocarbons and acid gases than EG or DEG. Quantifying this amount of absorption is therefore critical in order to minimize hydrocarbon losses or to optimize hydrocarbon recovery depending on the objective of the process. In this article, a new correlation that fully covers the operating ranges of TEG dehydration units is developed in order to determine the solubility of light alkanes and acid gases in TEG solvent. The influence of several parameters on hydrocarbon and acid gas solubility including temperature, pressure, and solvent content is also examined.     

Critical fluctuations of the micellar triethylene glycol monoheptyl ether-water system

Using the equal volume criterion and also the pseudospinodal conception the critical demixing point of the triethylene glycol monoheptyl ether/water system (C7E3H2O) has been determined as Ycrit=0.1 and Tcrit=296.46 K (Y, mass fraction of surfactant). From density measurements the critical micelle concentration (cmc) followed as Ycmc=0.007 at 288.15 K and Ycmc=0.0066 at 298.15 K. The (static) shear viscosity etas and the mutual diffusion coefficient D of the C7E3H2O mixture of critical composition have been evaluated to yield their singular and background parts. From a combined treatment of both quantities the relaxation rate Gamma of order parameter fluctuations has been derived. Gamma follows power law with universal critical exponent and amplitude Gamma0=3.1 x 10(9) s(-1). Broadband ultrasonic spectra of C7E3H2O mixtures exhibit a noncritical relaxation, reflecting the monomer exchange between micelles and the suspending phase, and a critical term due to concentration fluctuations. The former is subject to a relaxation time distribution that broadens when approaching the critical temperature. The latter can be well represented with the aid of the dynamic scaling model by Bhattacharjee and Ferrell (BF) [Phys. Rev. A. 31, 1788 (1985)]. The half-attenuation frequency in the scaling function of the latter model is noticeably smaller (Omega12 (BF) approximately 1) than the theoretically predicted value Omega12 (BF)=2.1. This result has been taken as an indication of a coupling between the fluctuations in the local concentration and the kinetics of micelle formation, in correspondence with the idea of a fluctuation controlled monomer exchange [T. Telgmann and U. Kaatze, Langmuir 18, 3068 (2002)].     

Self-assembly in complex mixed surfactant solutions: the impact of dodecyl triethylene glycol on dihexadecyl dimethyl ammonium bromide

The impact of the nonionic surfactant, dodecyl triethyleneglycol ether (C(12)E(3)) on the solution microstructure of the dialkyl chain cationic surfactant, dihexadecyl dimethyl ammonium bromide, (DHDAB) has been investigated. The variation in solution microstructure has been studied using a combination of small angle neutron scattering, ultra small angle neutron scattering, optical texture and photon correlation spectroscopy. At low surfactant concentrations (1.5 mM) the microstructure takes the form of bilamellar vesicles (BLV) for compositions containing less than 20 mol % of added C(12)E(3). Multilamellar vesicles (MLV) are the predominant microstructure for solutions richer in composition than 20 mol % C(12)E(3). At more than 80 mol % C(12)E(3), the solution microstructure reverts to that of a lamellar phase dispersion consistent with studies on the pure nonionic surfactant. At higher concentrations (60 mM) a wide continuous L beta phase region is observed for compositions in the range 20 to 80 mol % C(12)E(3). The fine details of the phase diagram were obtained from quantitative analysis of the SANS data using a well-established lamellar membrane model. Irrespective of the nonionic content, the bilayers are in general highly rigid, consistent with those stabilized by charge interactions. Furthermore estimates of the product of membrane moduli (compressibility and bending modulus) indicate that the different phase regions have very different membrane properties, however the magnitude of the variations observed are not predicted using existing theoretical treatments.     

Viscosimetric and ultrasonic studies of intermolecular interactions of 2-methoxyethanol with diethylene glycol,triethylene glycol and tetraethylene glycol binary mixtures

The viscosities at T = (293.15, 298.15 and 303.15) K and ultrasonic speeds at T = 298.15 K in the binary liquid mixtures of 2-methoxyethanol with diethylene glycol, triethylene glycol and tetraethylene glycol have been measured over the entire mixture compositions. From the experimental data, deviations in the viscosity (Δη), ultrasonic speed (Δu), and excess energies of activation for viscous flow (ΔG* ^E ) have been calculated. The viscosity data were correlated with equations of Hind et al., Grunberg and Nissan, Frenkel, and McAllister. The results are discussed in terms of intermolecular interactions and structure of studied binary mixtures.     

Low-temperature graft copolymerization of triethylene glycol dimethacrylate with oligomeric butadiene rubber

The kinetics of low-temperature graft copolymerization of triethylene glycol dimethacrylate with Krasol LBH-3000 oligobutadiene rubber was studied in relation to the initial mixture composition at 20°C. The experimental kinetic data were compared with the results of calculation by the suggested equation. The copolymer compositions were calculated from the extraction data in relation to the initial mixture compositions. The binary copolymerization constants were calculated by the analytical and graphical methods.     

Side products of methacrylic acid esterification with triethylene glycol methyl ether

Side reactions in the course of esterification of methacrylic acid with triethyleneglycol methyl ether in the presence of homogeneous acid catalyst have been studied. Chromato-mass spectrometry and authentic synthesis have revealed the chemical structure of the products; pathways of their formation have been suggested.     

Extraction of aromatic hydrocarbons from reformates with mixtures of triethylene glycol and sulfolane

Results are presented of a seven-stage counterflow extraction of C₆–C₈ aromatic hydrocarbons from the reformate of the gasoline fraction with a mixed extracting agent composed of triethylene glycol, sulfolane, and water, containing 37.6–57.6 wt % sulfolane.     

Dehumidification and humidification of air by surface-soaked liquid membrane module with triethylene glycol

A novel liquid membrane system, a surface-soaked liquid membrane, with triethylene glycol (TEG) on the hydrophilic-treated surface of the hydrophobic microporous membrane was developed and used for the dehumidification and humidification of air. The selectivity of the TEG liquid membrane for water vapor with respect to air was over 2000, which was derived from the selective absorption of the TEG liquid. A flat-type liquid membrane module with a dual membrane surface was designed, of which the TEG liquid membrane thickness was 18 μm and the permeation area was 0.13 m². The liquid membrane humidifier and dehumidifier consisted of the membrane module and a vacuum pump. As a dehumidifier, the membrane system recovered water vapor at 4.1 g/h from 70%RH room air at 298 K. For use as a humidifier, the air flow was effectively humidified by the permeated water vapor through the membrane module. The effects of the air humidity and sweep air flow rate were studied and discussed. Simple model calculations based on the permeability of the water vapor well predicted the experimental results.     

网络型聚三甘醇柠檬酸酯的合成、表征及其pH敏感性

用三甘醇(TG)和柠檬酸(CA)通过熔融缩聚的方法得到了一种网络型阴离子聚醚酯—聚三甘醇柠檬酸酯(PTGC).用FT-IR对预聚物的结构进行了初步表征,用ATIR、DSC、XRD对材料的结构进行了表征.考察了PTGC在不同pH值缓冲溶液中的溶胀行为.实验结果表明,PTGC的溶胀度随着柠檬酸的比例的增加先减小后增大.在碱性介质中PTGC的溶胀度显著增大,而在酸性介质中溶胀度显著减小,在pH<3的缓冲液中的溶胀度达到最小值.在pH 7.4的人工肠液和pH 1.0的人工胃液中PTGC的溶胀-收缩具有可逆性,显示出良好的pH敏感性,有望作为pH敏感口服结肠定位给药系统药物载体.     

Intermolecular interactions and properties of mixtures of triethylene glycol with ethanol and isopropyl alcohol

Density and viscosity of solutions formed in the systems triethylene glycol-ethanol and triethylene glycol-isopropyl alcohol were studied in the full concentration range at 20, 40, 50, and 60°C. The thermodynamic activation functions of viscous flow were calculated. The contribution of specific interactions to these functions was determined.     

Relative permittivity of the binary mixtures of 2-methoxyethanol with diethylene glycol,triethylene glycol,tetraethylene glycol,and polyethylene glycol 200 at various temperatures

Relative permittivities at T = (293.15, 298.15, and 303.15) K in the binary liquid mixtures of 2-methoxyethanol with diethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol 200 have been measured over the entire mixture compositions. The relative permittivity deviations (Δε) were calculated from these experimental data. The results are discussed in terms of intermolecular interactions and structure of studied binary mixtures.     

Doxorubicin compositions with biocompatible terpolymer of N-vinylpyrrolidone,methacrylic acid and triethylene glycol dimethacrylate

Compositions of doxorubicin with a terpolymer of N-vinylpyrrolidone, methacrylic acid and triethylene glycol dimethacrylate have been prepared and investigated by UV-VIS and NMR spectroscopy, cyclic voltammetry and DFT quantum chemical modeling. Oxygen containing groups of the terpolymer and hydrogen atoms of the drug OH and NH⁺ groups form hydrogen bonds. The compositions have lower cytotoxicity in vitro compared with that of free doxorubicin     

Mechanical and thermomechanical properties of densely crosslinked polymers based on triethylene glycol dimethacrylate copolymers

The static mechanical (uniaxial compression at a low strain rate $\dot \varepsilon $ ≤ 10^?4 s^?1) and thermomechanical properties of triethylene glycol dimethacrylate (M₁) copolymers with vinyl monomers (M₂) were studied and analyzed by means of a program developed earlier for identification of structural and physical features of macromolecular networks. The copolymer composition for each monomer pair was varied over the entire range of 0–100 mol % with a step size of 25 mol %. As M₂, monomers that ensure different types of unit distribution in chains were selected: alkyl methacrylates (random distribution), styrene (unit alternation tendency), butyl acrylate (block formation tendency), and vinyl acetate (tendency to form chains that are enriched initially in M₁ and finally, as M₁ is consumed, in M₂). To reveal the possible shielding effect capable of lowering the likelihood of the side process of intrachain crosslinking (cyclization), alkyl methacrylates with different degrees of bulkiness of the alkyl radical—methyl, butyl, and lauryl—were used. A systematic study of this representative set of test compounds showed that copolymerization imparted unusual and a priori unpredictable properties to the copolymers formed.     

Formation of N-vinylpyrrolidone homopolymer and its grafting during radiation-induced copolymerization with triethylene glycol dimethacrylate

The kinetics of radiation-induced copolymerization of N-vinylpyrrolidone with triethylene glycol dimethacrylate was studied. It was shown that the formation of a water-soluble N-vinylpyrrolidone homopolymer and its subsequent grafting onto the copolymer takes place in the system during the process. Copolymers containing up to 90 mol % N-vinylpyrrolidone in the macromolecular chain to provide their high sorption power were obtained.