Ion-chromatographic determination of seven common anions in electronic-grade, water-miscible solvents

An ion-chromatographic method has been developed to determine seven common anions in electronic-grade acetone, isopropyl alcohol, methanol, and N-methyl-2-pyrrolidone (NMP), solvents whose cleanliness is vital to the manufacturing of semiconductor devices. The system requires only a pump, conductivity detector, and switching valve as hardware. A calibration study was conducted first, by preparing and analyzing 11 concentrations (between 0.3 and 6.0 ng/g) in deionized (DI) water. Subsequently, a spiking study was performed by spiking each solvent at each of nine concentrations (between 50 and 500 ng/g). Dilutions of 1-100 (w/w) were prepared and analyzed. For each anion, recovered concentrations were estimated using the appropriate calibration curve. For each recovery curve, uncertainties in predicted concentrations were between +/-20 and +/-150 ng/g (except for phosphate in acetone), at 95% confidence. Recoveries were between 82% and 112% for all anions in all solvents, except for nitrite and nitrate in acetone, nitrite in methanol, and fluoride in N-methyl-2-pyrrolidone.     

Liquid-liquid equilibria for ternary systems of water-phenol and solvents: data and representation with models

Alvarez Gonzalez, J.R., Macedo, E.A., Soares, M.E. and Medina, A.G., 1986. Liquid-liquid equilibria for ternary systems of water-phenol and solvents: data and representation with models. Fluid Phase Equilibria, 26: 289–302.Liquid-liquid equilibrium data are presented for the systems water-phenol-benzene, water-phenol-ethylbenzene, water-phenol-nonanoic acid, water-phenol-ethyl acetate, water-phenol-isopropyl acetate, water-phenol-n-butyl acetate, water-phenol-isoamyl acetate and water-phenol-cyclohexyl acetate at 25°C and water-phenol-n-hexyl acetate at 25, 35 and 45°C. These systems are of practical interest for solvent extraction studies, as phenol constitutes a valuable raw material in the production of various chemicals and is recoverable from residual waters.The experimental data presented in this paper are correlated in terms of the NRTL and UNIQUAC models and the relevant parameters are presented.     

Nanostructure and amphiphile self-assembly in polar molecular solvents: amides and the "solvophobic effect"

The ability of low molecular weight amides to support amphiphile self-assembly is shown to be a general feature for this class of solvents. This report extends the number of known polar solvents which can support amphiphile self-assembly by five new amides; more than doubling the number of known amides able to serve as amphiphile self-assembly media. The formation of lyotropic liquid crystalline phases by cationic and non-ionic surfactants in these liquid amides is reported. The ability of a solvent to promote amphiphile self-assembly is governed by the "solvophobic effect" and is linked to the solvent cohesiveness. The Gordon parameter which is a measure of the solvent cohesiveness was found to provide a guide to an amides capacity to support lyotropic liquid crystalline phase diversity and thermal stability ranges of those phases. The "solvophobic effect" and steric hindrance factors were compared between amide's and protic ionic liquids possessing analogous chemical structures and also being able to promote amphiphile self-assembly.     

Hierarchically structured multifunctional porous interfaces through water templated self-assembly of ternary systems

Herein, a facile water-assisted templating approach, the so-called breath figures method, has been employed to prepare multifunctional and hierarchically structured porous patterned films with order at different length scales (nano- and micrometer). Tetrahydrofuran solutions of ternary blends consisting on high molecular weight polystyrene, an amphiphilic block copolymer, polystyrene-b-poly[poly(ethylene glycol) methyl ether methacrylate] (PS(40)-b-P(PEGMA300)(48)), and a fluorinated copolymer, polystyrene-b-poly(2,3,4,5,6-pentafluorostyrene) (P5FS(21)-b-PS(31)), have been used to obtain films varying the proportion of the three components. Confocal micro-Raman spectroscopy and atomic force microscopy demonstrated the preferential location of the different functionalities in the films. Because of the breath figures mechanism, the amphiphilic copolymer yield pores enriched in hydrophilic functionality while the fluorinated copolymer remained mixed with the PS matrix and eventually also forming self-assembled nanostructures at the surface. As a consequence, two levels of order can be observed, i.e., micrometer size pores with nanostructured domains due to the block copolymer self-assembly. In addition, the distribution of the amphiphilic copolymer within the holes is not regular being located principally on the edges of the cavities. This can be attributed to the coffee stain phenomenon occurring in the water droplets as a consequence of the segregation of the block copolymers to the droplets and their self-assembly.     

TBADH activity in water-miscible organic solvents: correlations between enzyme performance, enantioselectivity and protein structure through spectroscopic studies

The enantioselective reduction of 2-pentanone to (R)- and (S)-2-pentanol by Thermoanaerobacter (formerly Thermoanaerobium) brockii alcohol dehydrogenase (TBADH) in mixtures of water and water-miscible organic solvents was investigated. Significant enzymatic activity was retained in up to 87% methanol, ethanol and acetonitrile. The changes in enzyme activity as a function of organic solvent were correlated to structural alterations of TBADH with a series of spectroscopic studies (fluorescence, fluorescence quenching and circular dichroism (CD)). Interestingly, this study shows that the tetrameric form of TBADH is not critical for catalytic performance.     

Equilibrium liquid-vapor diagrams of ternary systems with three azeotropes

Forty-nine classes involving 222 types of ternary liquid-vapor systems with three azeotropes are revealed. The place of three-azeotrope systems in the thermodynamic classification of binary solutions is determined. Examples of phase portraits of liquid-vapor equilibrium with three azeotropes in various elements of the concentration triangle (binary components, internal region, and binary components and the internal region) are presented.     

Janus and ternary particles generated by microfluidic synthesis: design, synthesis, and self-assembly

This paper reports a microfluidic method for fast continuous synthesis of Janus particles and three-phase particles with narrow size distribution. Synthesis of particles included emulsification of monomer liquids and in-situ photoinitiated polymerization of multiphase droplets. We show the strategy for precise control over the structure of Janus particles and their structure-dependent assembly in clusters. We demonstrate an asymmetric chemical modification of the surface of JPs by conjugating them with protein molecules. The Janus and ternary particles were synthesized from largely immiscible liquids and had a sharp interface between the constituent phases.     

Solvophobicity and amphiphilic self-assembly in neoteric and nanostructured solvents

The emergence of ionic liquids and deep eutectics as neoteric solvents that support surfactant self-assembly creates a vast new playing field for creating new forms of soft matter with distinctive properties. Solvophobic self-assembly in ionic liquids and deep eutectics has unique and novel features arising from strong interactions between constituents, high ionic strengths, and the molecular structures of the components, which can induce amphiphilic nanostructure in these nonaqueous solvents. This nanostructure is often reminiscent of microemulsions and sponge phases. Here we review recent new understanding of solvent nanostructure and its effect on self-assembly of surfactants and lipids.     

具有特殊相互作用的聚合物共混物在选择性溶剂中的自组装行为

研究了磺化聚苯乙烯(SPS)/聚4-乙烯基吡啶(P4VP)在选择性溶剂甲醇中的自组装行为。用动态光散射的方法考察了P4VP/甲醇初始浓度以及Cu^2^+的加入对溶液中粒子尺寸的影响,并研究了Cu^2^+的加入对聚合物溶液粘度的影响。     

The effect of water-miscible organic solvents on the substitution reaction of Keggin-type heteropolysilicates and -germanates with vanadium(V) ion

The substitution reaction of Keggin-type polyoxometalates, [XM₁₂O₄₀]ⁿ⁻ (X = Si, Ge, P, or As; M = Mo or W), with vanadium(V) ion was investigated with cyclic voltammetry, Raman spectroscopy, and ³¹P NMR. The effect of organic solvents, such as acetonitrile (ACN), tetrahydrofuran (THF), formamide (FA), N-methylformamide (NMF), and N-methylacetoamide (NMA) on their substitution reactions was examined. In aqueous and aqueous-FA, -NMF, and -NMA solutions, the molybdenum or tungsten unit in the Keggin-anions was substituted with vanadium(V) ion to form V(V)-substituted polyoxometalates, while no substitution reaction occurred in aqueous-ACN and -THF solutions. It is suggested that this results from the relationship between the total anion charge and the permittivity of organic solvents.     

Developments in synthesis,characterization, and self-assembly of polycarbodiimide systems

Described herein is a comprehensive survey on the most recent advancements in polycarbodiimide synthetic methodologies, structure determination, property design, and self-assembly. In particular, the ¹⁵N-isotopic enrichment of polycarbodiimides is detailed along with the use of ¹⁵N NMR to identify the regioregularity and mechanism of chiroptical switching in polycarbodiimides. Furthermore, the new Ni(II) mediated “living” polymerization is explained along with its utilization in the incorporation of polycarbodiimides into block copolymers, graft copolymers, and star polymers. Finally, we review the recent discoveries focusing on the highly tunable self-assembly behaviors of polycarbodiimide homopolymers and copolymers. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2915–2934     

Comparison of different water-miscible solvents for the preparation of plasma and urine samples in metabolic profiling studies

The Lowry method and a capillary electrophoresis method were used to analyse protein residues in the supernatant after solvent deproteination of plasma. Acetonitrile and acetone were much more effective than methanol and ethanol at reducing the levels of proteins in plasma. The ability of different solvents to decrease levels of phospholipids in plasma samples was assessed using electrospray ionisation mass spectrometry (MS). Phospholipid signals can obscure differences between samples in general metabolite profiling (i.e. non-target compound) studies. Acetonitrile was much more effective than methanol in reducing the MS signal due to phospholipids in plasma which is a consequence of the poor solubility of phospholipids in acetonitrile. The capability of the solvents at reducing salts in urine samples was also studied by using an amperometric method. Using this approach little difference was detected between methanol, ethanol, acetonitrile and acetone in their ability to desalt urine samples.     

Protic ionic liquids: physicochemical properties and behavior as amphiphile self-assembly solvents

The physicochemical properties of 22 protic ionic liquids (PILs) and 6 protic molten salts, and the self-assembly behavior of 3 amphiphiles in the PILs, are reported. Structure-property relationships have been explored for the PILs, including the effect of increasing the substitution of ammonium cations and the presence of methoxy and hydroxyl moieties in the cation. Anion choices included the formate, pivalate, trifluoroacetate, nitrate, and hydrogen sulfate anions. This series of PILs had a diverse range of physicochemical properties, with ionic conductivities up to 51.10 mS/cm, viscosities down to 5.4 mPa.s, surface tensions between 38.3 and 82.1 mN/m, and densities between 0.990 and 1.558 g/cm3. PILs were designed with various levels of solvent cohesiveness, as quantified by the Gordon parameter. Fourteen PILs were found to promote the self-assembly of amphiphiles. High-throughput polarized optical microscopy was used to identify lamellar, hexagonal, and bicontinuous cubic amphiphile self-assembly phases. The presence and extent of amphiphile self-assembly have been discussed in terms of the Gordon parameter.     

Synthesis and characterization of novel ternary deep eutectic solvents简

A series of room-temperature ternary deep eutectic solvents(TDESs) were prepared from imidazolium halides, zinc halides and amides. The [BMIM]Cl–ZnCl2 –acetamide(1:1:1) system shows the lowest freezing point( 60 8C) and lowest density in the series. The viscosity and conductivity of TDESs have an exponential relationship with temperature and can be fitted by Arrhenius equation.     

Self-assembly in ternary systems: cross-linked polyelectrolyte,linear polyelectrolyte and surfactant

The competitive interactions in ternary systems consisting of a slightly cross-linked polyelectrolyte hydrogel and the mixture of linear polyelectrolyte and micelle forming surfactant both oppositely charged relative to the polyelectrolyte network were studied. It was shown that the equilibrium in the competitive reactions depends on the linear polyion charge density and the length of the surfactant aliphatic radical. Dependency on these characteristics the interpolyelectrolyte complex formed by cross-linked and linear polyelectrolytes can uptake surfactant ions from water solution transforming into the cross-linked polyelectrolyte-surfactant complex and releasing the linear polyelectrolyte or vice versa. The ternary systems of this kind are perspective to design the novel family of delivery constructs.     

Aqueous dispersion, surface thiolation, and direct self-assembly of carbon nanotubes on gold

We report the efficient aqueous dispersion of pristine HiPco single-walled carbon nanotubes (SWNTs) with ionic liquid (IL)-based surfactants 1-dodecyl-3-methylimidazolium bromide (1) and 1-(12-mercaptododecyl)-3-methylimidazolium bromide (2), the thiolation of nanotube sidewalls with 2, and the controlled self-assembly of positively charged SWNT-1,2 composites on gold. Optical absorption spectra and resonance Raman (RR) data of obtained aqueous SWNT-1,2 dispersions are consistent with debundled and noncovalently functionalized nanotubes whose electronic properties have not been disturbed. Additionally, the dispersion of pristine nanotube material with surfactants 1 and 2 leads to a high degree of purification from carbonaceous particles. The chiralities of the 14 smallest semiconducting HiPco SWNTs in resonance with Raman excitation at 1064 nm (1.165 eV) were determined in SWNT-2 aqueous dispersion using UV-vis-NIR and RR spectra. X-ray photoelectron spectroscopy (XPS) and surface-enhanced resonance Raman scattering (SERRS) spectroscopy of SWNT-2 submonolayers on gold verified the encapsulation of individualized SWNTs with IL surfactants, the cleavage of S-S disulfide bonds formed in aqueous SWNT-2 suspensions, and the direct chemisorption of the SWNT-2 composite on bare gold via the Au-S bond. Aqueous dispersions of SWNTs with IL-based surfactants add biofunctionality to carbon nanotubes by imparting the positive surface charge necessary for interactions with cell membranes. Our technique, which purifies pristine nanotube material and produces water-soluble, positively charged nanotubes with pendent surface-active thiol groups, may also be translated to other carbon nanotubes and carbon nanostructures. Self-assembled, positively charged submonolayers of SWNTs can be further used for applications in cell biology and sensor technology.     

The directed self-assembly of amphiphilic diblock copolymers in selective solvents

The directed self-assembly of diblock copolymers in solvents is studied systematically using a simulated annealing method. Effects of the shape, scale, and adsorption capacity of the induced surface on the morphology of the aggregates are examined. A variety of morphologies are predicted. By increasing the scale of induced surface, the micellar shape transforms from cylinder to sheet with a tail and finally to thin sheet without tail. The shape of induced surface determines the sheet’s shape, such as rounded and square. Configurations of hydrophobic blocks and interfacial energies are investigated by calculating the mean square end-to-end distances and the contact numbers between hydrophobic monomer and other species, respectively.     

Amphiphilicity and self-assembly behaviors of polystyrene-grafted multi-walled carbon nanotubes in selective solvents

Multi-walled carbon nanotubes (MWCNTs) can self-assemble as cylindrical bundles in some solvents after polystyrene (PS) grafting. In these three-dimensional regular structures, the tubes are oriented and parallel arranged. Every self-assembly structure has an order head and a comparatively loose tail. In order to find out the role that solvent plays, MWCNTs were dispersed in several organic solvents before and after modification. Based on macroscopic stability of suspensions and microscopic state of nanotubes, compatibility between solvents and MWCNTs can be confirmed. According to compatibility difference between tubes and PS, five chosen solvents are divided into three groups: selective solvent, good solvent, and bad solvent. MWCNT-g-PS can self-assemble only in selective solvents. Tetrahydrofuran and benzene are well compatible with PS, but bad with MWCNTs. Driven by the solvent–philic/solvent–phobic interaction, MWCNT-g-PS self-organized regularly as bundles. Because each part of the MWCNT-g-PS is compatible well with 1,2-dichlorobenzene, gathering tendency of the modified tubes have been enervated by their good compatibility and weak amphiphilicity. Grafted or not, nanotubes reveal poor compatibility with methanol and ethanol. Strong incompatibility and limited amphiphilicity make MWCNT-g-PS agglomerate as quickly and irregularly as raw tubes. An adapted hydrophilic/lipophilic balance system is introduced to qualify compatibility and amphiphilicity of MWCNT-g-PS in each solvent. This novel model not only reveals the relationship between solvent and microscopic state of unmodified/modified tubes, but also signifies the decisive role of solvent in self-assembly behaviors of MWCNT-g-PS.     

Rational design of a ternary supramolecular system: self-assembly of pentanuclear lanthanide helicates

The self-assembly of the first pentanuclear helicate was predicted on the structural basis obtained for linear and tetranuclear parent supramolecular compounds. Accordingly, the designed ternary supramolecular system requires appropriate polytopic organic receptors, which were successfully synthesized. Indeed, the formation of pentanuclear complexes was experimentally evidenced with NMR and ESMS spectra that perfectly reflect the expected pattern. The structural features in the europium pentanuclear complex are highlighted with semiempirical molecular modeling. The present work validates the combinatorial approach leading to the thermodynamically driven formation of tower-like pentanuclear edifices.