Introduction Of Liquid Research Articles

Separation of olefin/paraffin by electrodialysis

Transition metal ions, such as Ag+, can form complexes with olefins. In the present work, a cation exchange membrane loaded with an ionic liquid was prepared for the separation of olefin/paraffin by electrodialysis based on the complexing between olefins and Ag+. The effects of Ag+ concentration and current intensity on the separation efficiency were investigated. Experimental results indicate that, the introduction of choline lysine ionic liquid ([Ch][Lys]) to the cation exchange membrane significantly improved the olefin/paraffin separation efficiency. The Ag+ concentration and current intensity were optimized to be 1 mol/L and 0.002 A, respectively, which gave the separation selectivity to 1-hexene/n-hexane up to 9.5 and the permeation flux of 1-hexene up to 11.6 mL/cm2·h.

Comparative analysis between Liquid Based Cytology and Conventional Pap Smears at B P Koirala Memorial Cancer Hospital in Bharatpur, Chitwan, Nepal

Background and Objective: Liquid based cytology was introduced at B P Koirala Memorial Cancer Hospital in Bharatpur, Chitwan, Nepal, on 29th November 2017. The objective of this study was to compare the results of conventional pap smears over six (6) months periods from 29th May 2017 to 28th November 2017 with the results of liquid based cytology smears over six (6) months periods from 29th November 2017 to 28th May 2018.
 Methods: This is retrospective study. The results of conventional pap smears over 6 months and the results of liquid based cytology smears over 6 months periods were retrieved and analysed to give overall reporting profiles and compared between the two methods.
 Results: The percentage of unsatisfactory smears fell 3.9% by conventional pap smears methods where as the percentage of unsatisfactory smears fell 1.2% by liquid based cytology smears. There was an increase in the number of smears reported as dyskaryosis of any grade by liquid based cytology methods.
 Conclusion: The introduction of liquid based cytology led to improvements in unsatisfactory smear rates and also with significant pick up rates of dyskaryosis were maintained and improved.

Quantitative evaluation of analyte transport on microfluidic paper-based analytical devices (μPADs).

The transport efficiency during capillary flow-driven sample transport on microfluidic paper-based analytical devices (μPADs) made from filter paper has been investigated for a selection of model analytes (Ni2+, Zn2+, Cu2+, PO43-, bovine serum albumin, sulforhodamine B, amaranth) representing metal cations, complex anions, proteins and anionic molecules. For the first time, the transport of the analytical target compounds rather than the sample liquid, has been quantitatively evaluated by means of colorimetry and absorption spectrometry-based methods. The experiments have revealed that small paperfluidic channel dimensions, additional user operation steps (e.g. control of sample volume, sample dilution, washing step) as well as the introduction of sample liquid wicking areas allow to increase analyte transport efficiency. It is also shown that the interaction of analytes with the negatively charged cellulosic paper substrate surface is strongly influenced by the physico-chemical properties of the model analyte and can in some cases (Cu2+) result in nearly complete analyte depletion during sample transport. The quantitative information gained through these experiments is expected to contribute to the development of more sensitive μPADs.

WtF-Nano: One-Pot Dewatering and Water-Free Topochemical Modification of Nanocellulose in Ionic Liquids or γ-Valerolactone.

Ionic liquids are used to dewater a suspension of birch Kraft pulp cellulose nanofibrils (CNF) and as a medium for water‐free topochemical modification of the nanocellulose (a process denoted as “WtF‐Nano”). Acetylation was applied as a model reaction to investigate the degree of modification and scope of effective ionic liquid structures. Little difference in reactivity was observed when water was removed, after introduction of an ionic liquid or molecular co‐solvent. However, the viscoelastic properties of the CNF suspended in two ionic liquids show that the more basic, but non‐dissolving ionic liquid, allows for better solvation of the CNF. Vibrio fischeri bacterial tests show that all ionic liquids in this study were harmless. Scanning electron microscopy and wide‐angle X‐ray scattering on regenerated samples show that the acetylated CNF is still in a fibrillar form. 1 D and 2 D NMR analyses, after direct dissolution in a novel ionic liquid electrolyte solution, indicate that both cellulose and residual xylan on the surface of the nanofibrils reacts to give acetate esters.

Dry-inoculation method for thermal inactivation studies in wheat flour using freeze-dried Enterococcus faecium NRRL B-2354

Liquid cultures are commonly used to inoculate low-moisture foods. However, liquid-inoculation may generate varied results due to differences in preparation methods, and the introduction of liquid into a low-moisture matrix may cause stickiness and clumping. The objectives of this study were to develop a dry-inoculation method using freeze-dried Enterococcus faecium NBRL-2354, and to evaluate the stability of freeze-dried inoculum over time (35 days at −20 °C) in terms of survival and heat resistance. Two protectants, freeze-drying buffer and skim milk, mixed separately with liquid E. faecium were freeze-dried and their preservative effects were compared. Heat resistance of freeze-dried inoculum was determined by decimal reduction time at 80 °C (D80) in wheat flour (water activity 0.45 at room temperature). Freeze-drying buffer and skim milk formed slimy layers around bacterial cells and yielded freeze-dried inoculum with high survivability. D80-values of freeze-dried E. faecium protected by freeze-drying buffer or skim milk were 6.67 ± 0.22 min and 5.92 ± 0.39 min, respectively. Freeze-dried inoculum was stable with a high population concentration (>10.0 log CFU/g), while skim milk-protected inoculum showed stable heat resistance throughout storage. In summary, freeze-dried E. faecium protected by skim milk was the optimum dried inoculum and can be used as a substitute for liquid-inoculum in low-moisture foods.

A new method for improving the conductivity of alkaline membrane by incorporating TiO2- ionic liquid composite particles

In this paper, we prepared a series of ionic liquids including methyl ionic liquids, ethyl ionic liquids and hydroxyethyl ionic liquids. We used the common polymer backbone polyphenylene ether and the conventional conductive group triethylamine. We introduced three different ionic liquids to investigate different effects of the extent of ion conductivity improvement from its structure change. The introduction of ionic liquid significantly improved the ionic conductivity of the alkaline membrane. The highest conductivity of the composite membranes was 2.5 times higher than that of the pure membrane. A certain amount of nano-TiO2 was added into the membranes through ultrasound dispersion to form a series of trimethylamine-nano-TiO2-ionic liquid composite membranes. We found that TiO2-ethyl ionic liquid composite membrane has optimal performance, whose ionic conductivity up to 59.27mS/cm. and the degradation rate of ionic conductivity is 27.4% under strong alkali conditions. The water uptake and swelling ratio of the composite membrane are relatively low, and the thermal stability and mechanical properties also meet the requirements of the application.

高崎市における子宮頸がん検診での液状化検体細胞診導入成果

高崎市における子宮頸がん検診での液状化検体細胞診導入成果

Introduction of a novel basic ionic liquid containing dual basic functional groups for the efficient synthesis of spiro-4H-pyrans

In this research the synthesis of 1,1′-(butane-1,4-diyl)bis(1,4-diazabicyclo[2.2.2]octan-1-ium) hydroxide as an effective basic ionic liquid containing dual basic functional groups is reported. After characterization using FT-IR, 1H NMR, 13C NMR and mass analyses, this reagent is efficiently used for promotion of the synthesis of spiro-4H-pyrans via one-pot three-component condensation through a domino Knoevenagel/Michael/cyclization sequence. The attractive features of this process are simple procedure, short reaction times, high yields, no column chromatographic separation, commercial availability of the starting materials and recyclability of the catalyst.

Immobilization of a thiol-functionalized ionic liquid onto HKUST-1 through thiol compounds as the chemical bridge

The IL@HKUST-1 catalyst was synthesized by a post-synthetic modification strategy. The introduction of ionic liquid greatly improved the acidity of the material, making it an efficient and recyclable catalyst for the esterification reaction.

Solid-state ion-selective electrodes based on ionic liquid solid at room temperature for detecting amino acids

An ion-selective electrode based on tetraoctylammonium N-lauroyl sarcosinate ionic liquid, which is solid at room temperature, is responsive to anionic forms of amino acids. Preconditioning in copper sulfate solution and the introduction of more high-melting and hydrophobic ionic liquid (1,3-dihexade-cylimidasolium bromide) allowed the limit of detecting phenylalanine to be lowered by several times (cmin = 2.7 × 10–5 M) and significantly improves the service life of the ion-selective electrode. The possibility was shown for using two ionic liquids for designing ISE with one of them that serves as an inert solid matrix for immobilizing the second one, which in turn ensured the analyte binding and the generation of a potentiometric signal.

Comparison of conventional pap smear versus liquid based cytology in a diagnostic centre of central Madhya Pradesh

Introduction: Cervical cancer is the second leading cause of cancer related deaths, next only to breast cancer worldwide, but is easily preventable if detected early. However conventional paps smear technique has many limitations. To overcome these limitations liquid based cytology was introduced in the mid 1990 as a better tool for processing cervical samples the present study was undertaken to compare conventional paps smear with liquid based methods and to assess the diagnostic accuracy of LBC in our setting. Materials and Methods: The present study was a prospective study conducted on the first 300 patients visiting our diagnostic centre for pap smear tests from May to October 2015. The samples were collected with Rovers Cervex brush and a conventional slide was prepared and the brush head was detached and suspended in the preservative fluid. Split samples of CPS and LBC were analysed and reported using the Bethesda system 2001 and results were compared Results: While only 5 patients were found to have unsatisfactory smear in LBC (1.67%), 20 patients had unsatisfactory smear in conventional smear (6.67%). Endocervical cells were not seen in conventional pap smears while LBC showed presence of endocervical cells in all patients. Candida bodies were not evident in LBC smears while the CPS showed presence of candida bodies in 5 cases. ASCUS was reported in 10 (3.31%) patients by CPS while it was found to be present in only 6(2%) patients by LBC technique. Conclusion: The introduction of liquid based cytology technique has brought about a revolution in the field of cervical screening programmes because of its advantages like reduced rate of unsatisfactory smears, increased number of satisfactory smears with adequate endocervical cells, optimal preservation and staining of cellular material, small area on the slide for screening hence lesser time for reporting and non interference by blood, mucus and other cell debris, air drying artefacts which hampers the proper detection of cellular abnormalities by the conventional method and may replace the conventional smear slowly but steadily. Key words: LBC, CPS, Pap smear, Cervical cancer

High-Sensitive Glucose Biosensor Based on Ionic Liquid Doped Polyaniline/Prussian Blue Composite Film

The Prussian blue/ionic liquid-polyaniline/multiwall carbon nanotubes (PB/IL-PANI/MWNTs) composite film was fabricated by using cyclic voltammetry. The ion liquid acting as a lubricating agent, could enhance the electron delocalization degree and reduce the structural defects of the polyaniline. The surface morphology of the composite film revealed that the PB nanoparticles have smaller size than that in pure PB film. Due to the introduction of ion liquid, the PB/IL-PANI/MWNTs composite film showed wonderful synergistic effect which can remarkably enhance sensitivity, expand linear range and broaden acidic adaptability for hydrogen peroxide detection. The composite film demonstrated good stability in neutral solution contrast to pure PB film, with a linear range from 2.5 µmol/L to 0.5 mmol/L and a high sensitivity of 736.8 µA·(mmol/L)−1·cm−2 for H2O2 detection. Based on the composite film, an amperometric glucose biosensor was then fabricated by immobilizing glucose oxidase. Under the optimal conditions, the biosensor also exhibits excellent response to glucose with the linear range from 12.5 µmol/L to 1.75 mmol/L and a high sensitivity of 94.79 µA·(mmol/L)−1·cm−2 for H2O2. The detection limit was estimated 1.1 µmol/L. The resulting biosensor was applied to detect the blood sugar in human serum samples without any pretreatment, and the results were comparatively in agreement with the clinical assay.

The influence of ionic liquids on curing rheokinetics and properties of strengthening composition based on polyesterurethane rubber with epoxyurethane groups

A study of the influence of ionic liquids on the curing and properties of a strengthening composition based on polyesterurethane rubber with epoxyurethane end groups has been carried out. The catalytic activity of ionic liquids has been found to be dependent on the anion chemical structure and to increase as the anion size decreases. It has been shown that introduction of methylbenzylamine and ionic liquid (1-ethyl-3-methyl-imidazolyl dicyanamide) results in strengthening compositions with close mechanical properties, lifetime, swelling in transformer oil, and glass transition temperature.

Hybrid Ionic Liquid-Chitosan Membranes for CO2 Separation: Mechanical and Thermal Behavior

Abstract Pure chitosan (CS) and hybrid ionic liquid-chitosan membranes loaded with 5 wt% 1-ethyl-3-methylimidazolium acetate ([emim][Ac]) ionic liquid were prepared in order to improve the thermal behavior of supported ionic liquid membranes (SILMs) for CO2 separation. Gas permeability, solubility and diffusivity were evaluated in the temperature range 298–323 K. The temperature influence was well described in terms of the Arrhenius–van’t Hoff exponential relationships. Activation energies were calculated and compared with those obtained for SILMs with the same ionic liquid. The introduction of this ionic liquid in the hybrid solid membrane decreases the permeability activation energy, leading to a lower influence of the temperature in the permeability and diffusivity. Moreover, the thermal behavior is similar to pure chitosan membranes, and the mechanical strength and flexibility were improved due to the introduction of the ionic liquid in the polymer matrix.

Measurements of non-reacting and reacting flow fields of a liquid swirl flame burner

The understanding of the liquid fuel spray and flow field characteristics inside a combustor is crucial for designing a fuel efficient and low emission device. Characterisation of the flow field of a model gas turbine liquid swirl burner is performed by using a 2-D particle imaging velocimetry(PIV) system. The flow field pattern of an axial flow burner with a fixed swirl intensity is compared under confined and unconfined conditions, i.e., with and without the combustor wall. The effect of temperature on the main swirling air flow is investigated under open and non-reacting conditions. The result shows that axial and radial velocities increase as a result of decreased flow density and increased flow volume. The flow field of the main swirling flow with liquid fuel spray injection is compared to non-spray swirling flow. Introduction of liquid fuel spray changes the swirl air flow field at the burner outlet, where the radial velocity components increase for both open and confined environment. Under reacting condition, the enclosure generates a corner recirculation zone that intensifies the strength of radial velocity. The reverse flow and corner recirculation zone assists in stabilizing the flame by preheating the reactants. The flow field data can be used as validation target for swirl combustion modelling.

Phosphotungstic Acid Immobilized on Ionic Liquid-Modified SBA-15: Efficient Hydrophobic Heterogeneous Catalyst for Oxidative Desulfurization in Fuel

A heterogeneous catalyst system was synthesized by immobilizing phosphotungstic acid on ionic liquid-modified mesoporous silica SBA-15 and applied in oxidative desulfurization. Structure and properties of catalyst were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and the contact angle. The results demonstrated that the synthesized catalyst possessed ordered mesopore structure and high special surface area. Due to the introduction of imidazole-based ionic liquid, the catalyst exhibited good wettability for model oil, which had significant contribution to desulfurization activity. Both DBT and 4,6-DMDBT could be removed completely at mild conditions (60 °C, 40 min). The removal of BT also can reach 81.3% within 60 min. Furthermore, the catalyst was recovered and reused in four reaction runs with a slight decrease in activity.

Tuning the Morphology of GeS2 Hybrid Materials Using Ionic Liquids as Structuring Agents

AbstractControl of the surface chemistry and morphology of chalcogenide materials, which are highly polarizable, is a very interesting challenge as it might lead to breakthroughs in various fields such as electrochemistry, catalysis, and gas‐phase separation. With this in mind, a new approach to synthesize structured Ge‐based chalcogenide products has been investigated. It involves the use of tetraethoxygermanium (TEOG) and thioacetamide with an ionic liquid (IL) as structuring agent. This innovative synthesis process has two main advantages: it is performed under soft conditions, and it also enables the morphological control of the obtained hybrid organic–GeS2 particles. In the absence of the IL, the synthesis leads to an agglomeration of nanospheres, whereas the introduction of the ionic liquid leads either to microspheres or to gypsum rosette‐like particles. It has been clearly highlighted that the morphology of the hybrid organic–GeS2 particles strongly depended on the nature of the cationic part of the IL.

Introduction of an Ionic Liquid into the Micropores of a Metal–Organic Framework and Its Anomalous Phase Behavior

AbstractControlling the dynamics of ionic liquids (ILs) is a significant issue for widespread use. Metal–organic frameworks (MOFs) are ideal host materials for ILs because of their small micropores and tunable host–guest interactions. Herein, we demonstrate the first example of an IL incorporated within the micropores of a MOF. The system studied consisted of EMI‐TFSA (1‐ethyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)amide) and ZIF‐8 (composed of Zn(MeIM)2; H(MeIM)=2‐methylimidazole) as the IL and MOF, respectively. Construction of the EMI‐TFSA in ZIF‐8 was confirmed by X‐ray powder diffraction, nitrogen gas adsorption, and infrared absorption spectroscopy. Differential scanning calorimetry and solid‐state NMR measurements showed that the EMI‐TFSA inside the micropores demonstrated no freezing transition down to 123 K, whereas bulk EMI‐TFSA froze at 231 K. Such anomalous phase behavior originates from the nanosize effect of the MOF on the IL. This result provides a novel strategy for stabilizing the liquid phase of the ILs down to a lower temperature region.

Introduction of an ionic liquid into the micropores of a metal-organic framework and its anomalous phase behavior.

Controlling the dynamics of ionic liquids (ILs) is a significant issue for widespread use. Metal-organic frameworks (MOFs) are ideal host materials for ILs because of their small micropores and tunable host-guest interactions. Herein, we demonstrate the first example of an IL incorporated within the micropores of a MOF. The system studied consisted of EMI-TFSA (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide) and ZIF-8 (composed of Zn(MeIM)2 ; H(MeIM)=2-methylimidazole) as the IL and MOF, respectively. Construction of the EMI-TFSA in ZIF-8 was confirmed by X-ray powder diffraction, nitrogen gas adsorption, and infrared absorption spectroscopy. Differential scanning calorimetry and solid-state NMR measurements showed that the EMI-TFSA inside the micropores demonstrated no freezing transition down to 123 K, whereas bulk EMI-TFSA froze at 231 K. Such anomalous phase behavior originates from the nanosize effect of the MOF on the IL. This result provides a novel strategy for stabilizing the liquid phase of the ILs down to a lower temperature region.

Influence of riser design on macrosegregation in static castings

The flow between a casting and riser and the consequent macrosegregation development in an aluminium alloy is examined. The riser is designed using Campbell’s rules and solidification is simulated. The influence of cooling conditions and riser shape on macrosegregation patterns is studied. The relative importance of buoyancy and shrinkage induced flows is also simulated. For castings with a fixed riser shape, the average composition in the cast part increases due to the exchange of interdendritic fluid between the riser and the part. This exchange is smaller at higher solidification rates and when the bottom of the mould is chilled. Although the buoyancy induced flow does move some interdendritic liquid from the riser to the casting, shrinkage is more significant in increasing its average composition. A wider riser provides a barrier to flow, slowing the introduction of heavier interdendritic liquid from the riser into the casting, keeping it closer to the nominal composition.