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Solution liquid solid

Zhengcai Zhang, Guang-Jun Guo
Although ice powders are widely used in gas hydrate formation experiments, the effects of ice on hydrate nucleation and what happens in the quasi-liquid layer of ice are still not well understood. Here, we used high-precision constant energy molecular dynamics simulations to study methane hydrate nucleation from vapor-liquid mixtures exposed to the basal, prismatic, and secondary prismatic planes of hexagonal ice (ice Ih). Although no significant difference is observed in hydrate nucleation processes for these different crystal planes, it is found, more interestingly, that methane hydrate can nucleate either on the ice surface heterogeneously or in the bulk solution phase homogeneously...
July 18, 2017: Physical Chemistry Chemical Physics: PCCP
Sonja Platzer, Raphlin Leyma, Sara Wolske, Wolfgang Kandioller, Esther Heid, Christian Schröder, Michael Schagerl, Regina Krachler, Franz Jirsa, Bernhard K Keppler
We studied the extraction behavior of two thioglycolate-based ionic liquids (ILs), for heavy metals from aqueous solutions; substances of interest were methyltrioctylammonium S-hexyl thioglycolate [N1888][C6SAc] and methyltrioctylphosphonium S-hexyl thioglycolate [P1888][C6SAc]. Theses ILs previously have shown very good extraction abilities towards cadmium and copper, therefore we investigated time-dependent metal removal experiments with aqueous solutions of cobalt(II), nickel(II) and zinc(II). The highest distribution ratio (RIL/Water) was determined for zinc (RIL/Water=2000)...
June 23, 2017: Journal of Hazardous Materials
Pekka Peljo, Micheál D Scanlon, Astrid Johana Olaya, Lucie Rivier, Evgeny Smirnov, Hubert H Girault
Redox electrocatalysis (catalysis of electron transfer reactions by floating conductive particles) is discussed from the point-of-view of Fermi level equilibration, and an overall theoretical framework is given. Examples of redox electrocatalysis in solution, in bipolar configuration and at liquid-liquid interfaces are provided, highlighting that bipolar and liquid-liquid interfacial systems allow the study of the electrocatalytic properties of particles without effects from the support, but only liquid-liquid interfaces allow measurement of the electrocatalytic current directly...
July 14, 2017: Journal of Physical Chemistry Letters
Jipeng Guan, Yanyuan Wang, Chenyang Xing, Lijun Ye, Yongjin Li, Jingye Li
Herein, we report a simple strategy to synthesize quasi-block graft copolymers using the binary phase structure of semicrystalline polymers as the template. An unsaturated ionic liquid, 1-vinyl-3-butylimidazolium bis (trifluoromethylsulfonyl) imide ([VBIm] [TFSI]), is thermodynamically miscible with poly (vinylidene fluoride-co-hexafluoropropylene) (P(VDF-co-HFP)) in solution. The solidification of P(VDF-co-HFP)/[VBIm] [TFSI] blend leads to the expelling of ILs from the crystalline region and the ILs are only located in the amorphous region...
July 13, 2017: Journal of Physical Chemistry. B
Oliver S Hammond, Daniel Timothy Bowron, Andrew J Jackson, Thomas Arnold, Adrian Sanchez-Fernandez, Nikolaos Tsapatsaris, Victoria Garcia Sakai, Karen J Edler
Little is presently known about the unique nanostructure of Deep Eutectic Solvents (DES). The order of the liquid-solid phase transition is contended and whether DES-water mixtures are merely aqueous solutions, or have properties dominated by the eutectic pair, is unclear. Here, we unambiguously show the structure of choline chloride-malic acid (malicine) as a liquid, and also in solid and hydrated forms, using neutron total scattering on D/H isotope-substituted samples, and quasi-elastic neutron scattering (QENS)...
July 12, 2017: Journal of Physical Chemistry. B
Yazgan Tuna, Ji Tae Kim, Hsuan-Wei Liu, Vahid Sandoghdar
We report on the manipulation of a plasmonic nanoantenna in an aqueous solution using an electrostatic trap created between a glass nanopipette and a substrate. By scanning a trapped gold nanosphere in the near field of a single colloidal quantum dot embedded under the substrate surface, we demonstrate about eight-fold fluorescence enhancement over a lateral full width at half-maximum of about 45 nm. We analyze our results with the predictions of numerical electromagnetic simulations under consideration of the electrostatic free energy in the trap...
July 11, 2017: ACS Nano
Nor Zuliana Yusof, Zafarizal Aldrin Azizul Hasan, Zulina Abd Maurad, Zainab Idris
Eye irritation tests are widely used to assess the ocular irritancy of chemicals. Measurement of eye irritancy is necessary for safety evaluation of both industrial and consumer products. The eye irritancy assessment of palm-based methyl ester sulphonates (MES) of different chain lengths; C12, C14, C16, C16:18 were evaluated using Top-Down approach strategy as suggested by European Centre for the Validation of Alternative Methods. The Bovine Corneal Opacity and Permeability test method (BCOP), OECD Test Guideline 437, was used as an initial step to study the inducing effect of palm-based MES on irreversible eye damage...
July 10, 2017: Cutaneous and Ocular Toxicology
Ujjal Bhattacharjee, Daniel Freppon, Long Men, Javier Vela, Emily A Smith, Jacob W Petrich
The ability to produce large-scale, reversible structural changes in a variety of materials by photoexcitation of a wide variety of azobenzene derivatives has been recognized for almost two decades. Because photoexcitation of trans-azobenzene produces the cis isomer in solution, it has generally been inferred that the macroscopic structural changes occurring in materials are also initiated by a similar large-amplitude, trans-to-cis isomerization. This work provides the first demonstration that a trans-to-cis photoisomerization occurs in polycrystalline azobenzene, and is consistent with the previously hypothesized nature of the trigger in the photoactuated mechanisms of the materials in question...
July 9, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Andrew I Cooper
Until recently, porous molecular solids were isolated curiosities with properties that were eclipsed by porous frameworks, such as metal-organic frameworks. Now molecules have emerged as a functional materials platform that can have high levels of porosity, good chemical stability, and, uniquely, solution processability. The lack of intermolecular bonding in these materials has also led to new, counterintuitive states of matter, such as porous liquids. Our ability to design these materials has improved significantly due to advances in computational prediction methods...
June 28, 2017: ACS Central Science
Yuefei Ji, Lu Wang, Mengdi Jiang, Yan Yang, Peizeng Yang, Junhe Lu, Corinne Ferronato, Jean-Marc Chovelon
Sulfaquinoxaline (SQX) is a coccidiostatic drug widely used in poultry and swine production and has been frequently detected in various environmental compartments such as surface water, groundwater, soils, and sediments. In the present study, degradation of SQX by ferrous ion-activated peroxymonosulfate oxidation process (Fe(II)/PMS), a promising in situ chemical oxidation (ISCO) technique, was systematically investigated. Experimental results showed that Fe(II)/PMS process appeared to be more efficient for SQX removal relative to Fe(II)/persulfate process (Fe(II)/PS)...
July 5, 2017: Environmental Science and Pollution Research International
Raheleh Hamedi, Mohammad Reza Hadjmohammadi
A novel design of hollow fiber liquid phase microextraction containing multiwalled carbon nanotubes as a solid sorbent, which is immobilized in the pore and lumen of hollow fiber by the sol-gel technique was developed for the pre-concentration and determination of polycyclic aromatic hydrocarbons in environmental water samples. The proposed method utilized both solid- and liquid-phase microextraction media. Parameters that affect the extraction of polycyclic aromatic hydrocarbons were optimized in two successive steps as follows...
July 4, 2017: Journal of Separation Science
Guizhen Li, Xiaoqin Wang, Kyung Ho Row
Different kinds of deep eutectic solvents (DES) based on choline chloride (ChCl) and ionic liquids (ILs) based on 1-methylimidazole were used to modify Fe3O4/molecularly imprinted polymers (Fe3O4/MIPs), and the resulting materials were applied for the rapid purification of alkaloid isomers (theobromine and theophylline) from green tea with magnetic solid-phase extraction (M-SPE). The M-SPE procedure was optimized using the response surface methodology (RSM) to analyze the maximum conditions. The materials were characterized by Fourier transform infrared spectroscopy (FI-IR) and field emission scanning electron microscopy (FE-SEM)...
June 25, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Li Mi, Jiachao Yu, Fei He, Ling Jiang, Yafeng Wu, Lijun Yang, Xiaofeng Han, Ying Li, Anran Liu, Wei Wei, Yuanjian Zhang, Ye Tian, Songqin Liu, Lei Jiang
The low solubility of gases in aqueous solution is the major kinetic limitation of reactions that involve gases. To address this challenge, we report a nanochannel reactor with joint gas-solid-liquid interfaces and controlled wettability. As a proof of the concept, the porous anodic alumina (PAA) nanochannel membrane with different wettability is used for glucose oxidase (GOD) immobilization, which contacts with glucose aqueous solution on one side, while the other side gets in touch with the gas phase directly...
June 30, 2017: Journal of the American Chemical Society
Vikram Singh Raghuwanshi, Jielong Su, Christopher J Garvey, Stephen A Holt, Peter J Holden, Warren J Batchelor, Gil Garnier
Quantification of adsorbed biomolecules (enzymes, proteins) at the cellulose interface is a major challenge in developing eco-friendly biodiagnostics. Here, a novel methodology is developed to visualize and quantify the adsorption of antibody from solution to the cellulose-liquid interface. The concept is to deuterate cellulose by replacing all nonexchangeable hydrogens from the glucose rings with deuterium in order to enhance the scattering contrast between the cellulose film surface and adsorbed antibody molecules...
July 12, 2017: Biomacromolecules
Hassan Sereshti, Sadjad Bakhtiari, Hamid Najarzadekan, Soheila Samadi
An electrospun polyethylene terephthalate/graphene oxide nanofibrous mat was fabricated and used as an effective and novel membrane for the solid-phase extraction of tamoxifen in human blood plasma samples before detection by high-performance liquid chromatography. The membrane was characterized by some identification techniques, such as FTIR spectroscopy, X-ray diffraction, and scanning electron microscopy. The effective variables of the extraction procedure including desorption condition (type and volume of the eluent), adsorbent dose, pH of sample solution, salt concentration, and sample loading time were investigated and their optimum values were obtained using one factor at a time methodology...
June 30, 2017: Journal of Separation Science
Lifu Chen, Eden E L Tanner, Richard G Compton
The adsorption of phenyl hydroquinone (PHQ) on graphene surfaces at the liquid-solid interface is investigated revealing a flat orientation and two different vertically adsorbed states of PHQ on graphene nanoplatelets (GNPs), namely edgewise or endwise adsorption. The transition between these states is driven by increasing concentrations of PHQ in solution leading to increased absolute coverages on the graphene surface. At low adsorbate concentrations (≤21 mM), the adsorption process is also shown to be Langmuirian with an adsorption constant of (9...
July 21, 2017: Physical Chemistry Chemical Physics: PCCP
Abhijeet Kumar, Jochen Kleinen, Joachim Venzmer, Tatiana Gambaryan-Roisman
An analytical approach is presented to describe pressure-driven streaming current (Istr) and streaming potential (Ustr) generation in geometrically complex samples for which the classical Helmholtz-Smoluchowski equation is known to be inaccurate. The new approach is valid under the same prerequisite conditions which are used for the development of the Helmholtz-Smoluchowski equation, i.e. the electric double layers are sufficiently thin, and surface conductivity and electroviscous effects are negligible. The analytical methodology is developed using linear velocity profiles to describe liquid flow inside electrical double layers, and using simplifying approximations to describe macroscopic flow...
June 28, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Letian Dou, Minliang Lai, Christopher S Kley, Yiming Yang, Connor G Bischak, Dandan Zhang, Samuel W Eaton, Naomi S Ginsberg, Peidong Yang
Halide perovskites are promising semiconductor materials for solution-processed optoelectronic devices. Their strong ionic bonding nature results in highly dynamic crystal lattices, inherently allowing rapid ion exchange at the solid-vapor and solid-liquid interface. Here, we show that the anion-exchange chemistry can be precisely controlled in single-crystalline halide perovskite nanomaterials when combined with nanofabrication techniques. We demonstrate spatially resolved multicolor CsPbX3 (X = Cl, Br, I, or alloy of two halides) nanowire heterojunctions with a pixel size down to 500 nm with the photoluminescence tunable over the entire visible spectrum...
June 26, 2017: Proceedings of the National Academy of Sciences of the United States of America
Xiaoqin Wang, Guizhen Li, Kyung Ho Row
Magnetic graphene oxide was modified by four imidazole-based ionic liquids to synthesize materials for the extraction of polysaccharides by magnetic solid-phase extraction. Fucoidan and laminarin were chosen as the representative polysaccharides owing to their excellent pharmaceutical value and availability. FTIR spectroscopy, field-emission scanning electron microscopy and thermogravimetric analysis were applied to characterize the synthesized materials. Single-factor experiments showed that the extraction efficiency of polysaccharides was affected by the amount of ionic liquids for modification, solid-liquid ratio of brown alga and ethanol, the stirring time of brown alga and ionic liquid modified magnetic graphene oxide materials, and amount of 1-(3-aminopropyl)imidazole chloride modified magnetic graphene oxide materials added to the brown alga sample solution...
June 23, 2017: Journal of Separation Science
Shuping Ma, Xucan Yuan, Pengfei Zhao, Hong Sun, Xiu Ye, Ning Liang, Longshan Zhao
A novel and reliable method for determination of five triazole fungicide residues (triadimenol, tebuconazole, diniconazole, flutriafol and hexaconazol) in Traditional Chinese Medicine samples was developed using dispersive solid-phase extraction combined with ultrasound-assisted dispersive liquid-liquid microextraction before ultra high performance liquid chromatography with tandem mass spectrometry. The clean-up of extract was conducted using dispersive solid-phase extraction by directly adding sorbents into the extraction solution, followed by shaking and centrifugation...
June 22, 2017: Journal of Separation Science
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