Anhydrous Ethanol Solution Research Articles

Study on the microwave absorbing properties of SiC@Ni powders with core@shell structure

Hybridization of dielectric and magnetic materials is considered a promising option for the preparation of electromagnetic wave absorbing materials with excellent properties. In this paper, SiC@Ni powders were prepared by a surface heat-assisted process, in which SiC was first cleaned sequentially with anhydrous ethanol and NaOH solutions, and the samples were etched into a mixed solution of HF and HCl, the SiC@Ni powders were then mixed at high speed at 120 °C under argon atmosphere. The sample were characterized by Scanning electron microscopy (SEM) and vector network analyzer (VNA). It is found that the absorption characteristics of SiC@Ni in the 2–18 GHz band are significantly enhanced due to the introduction of the ni layer which enhances the loss of the sample to solve the problem of a single absorption mechanism and high impedance of SiC. The reflection loss value of SiC@Ni in the 8.7 GHz band decreases to − 22.45 dB when the material thickness is 2.5 mm, the effective absorption frequency width is 2.5 GHz, which is a significant advantage over the initial SiC. The experimental methodology of this work is simple and easy to follow, and provides some guidance for the large-scale production of SiC-based microwave absorbing materials.

In‐situ doping and post‐treatments modulate the photoelectrical properties and stability of electropolymerization poly(3,4‐ethylenedioxythiophene)

AbstractPoly(3,4‐ethylenedioxythiophene) (PEDOT) has been widely used in electrode materials, electrochromic materials, biosensors, supercapacitor, and solar cells, etc. In these applications, high requirement for the stability of PEDOT is indispensable. This study focused on enhancing the stability of electro‐polymerized PEDOT electrodes by in‐situ doping and solvent treatment in order to reduce the dissolution products of PEDOT under photoelectric conditions. The post‐treatment was a combination of soaking and/or rising with deionized water, anhydrous ethanol and sulfuric acid solution (pH = 2) for different times. Among them, the sample rinsed successively with anhydrous ethanol and deionized water was the most effective post‐treatment method, which can reduce the dissolution amount by 35%. Through doping para‐toluenesulfonic acid (TsOH), the dissolution amount was further decreased by 58%. The surface hydrophobicity of PEDOT was increased from 23° to 38° after doping with TsOH, which was beneficial to the stability of PEDOT. Except for sodium polystyrene sulfonate (PSS) doping, the photocurrent response of PEDOT can be increased by doping other selected substances. Specially, the photocurrent response of TsOH‐PEDOT was increased by 59%. There is a certain negative correlation between dissolution amount and the photocurrent response, suggesting less dissolution is conductive to maintaining high photoelectric performance.

Possible physiological mechanism of exogenous vitamin E influencing shelf life, physicochemical quality, and microorganism of fresh‐cut water chestnuts

Prolonging shelf life of fresh-cut water chestnuts (FCWC) by vitamin E (vit E) was investigated. Browning degree, decay degree, and edible quality (EQ) of FCWC were evaluated as evaluation indexes of shelf life. Meanwhile, total soluble solids concentration, titratable acid (TA) concentration, ascorbic acid (AA) concentration, hardness, ethylene concentration, polyphenol oxidase (PPO) activity, peroxidase (POD) activity, total phenols (TP) concentration, counts of thermophilic bacteria, yeasts, and molds colonies were analyzed. Shelf life of FCWC could be prolonged for 4 days by soaking them in 0.04% (v v−1) vit E anhydrous ethanol (1% [v v−1]) solution for 30 min. Vit E probably inhibited the increasing of PPO and POD activities, and the declining of TP concentration and hardness. Vit E had little effect on counts of thermophilic bacteria, yeasts, and molds colonies of FCWC. These results indicated that vit E could prolong shelf life of FCWC. Novelty impact statement Vitamin E (vit E) extents shelf life of fresh-cut water chestnuts for 4 days. Vit E inhibits browning by reacting with oxygen or by reducing polyphenol oxidase and peroxidase activities. Vit E has no effect on total soluble solids, titratable acid, ascorbic acid, and ethylene concentration.

Synthesis of double emission Mn2+ doped CsPb (Cl/Br)3/SiO2 nanocrystals under the ethanol solution

Perovskite quantum dots (QDS) are promising candidate optoelectronics application materials for their excellent tuning performance and high photoluminescence quantum yield. Herein, we report a strategy to synthesize MnCl2-doped CsPbBr3 NCs and accomplish adjusting their optical properties in wide color gamut. The colloidal MnCl2-doped CsPbBr3 NCs was synthesized by adding CsPbBr3 powder and MnCl2 in anhydrous ethanol solution, and the double emission nanocrystals with tunable spectra were prepared successfully. PL, lifetime absorption, PLQY, XRD, TEM were tested and encapsulated in the device. Through testing, the luminescence mechanism of Mn2+ doped perovskite quantum dots is discussed in detail. After doping Mn2+, the energy of quantum dots is transferred to Mn2+, which causes the energy level transition. The material emits orange yellow light, and the best material PLQY can reach 45.2%. XRD and TEM tests show that they have good crystallinity. Finally, we encapsulate it and prepare white LED. Compared with other ion exchange methods, MnCl2 can be dissolved indefinitely in ethanol solution, so MnCl2 can be prepared with arbitrary doping ratio of manganese doped CsPb(Cl/Br)3 nanocrystals. This method is simple and can be used in mass production, which lays a foundation for industrial production.

Rational synthesis of ZnO decorated Fe hierarchical nanostructures for enhanced photocatalytic performance by long-pulse-width laser ablation of binary alloys target

Abstract Here we present a facile approach for the controllable synthesis of multifunctional ZnO decorated Fe hierarchical nanostructures, including ZnO quantum dots (QDs) decorated Fe nanowires, flocky Fe@ZnO core-shell nanospheres (Fe@ZnO CSNSs), ZnO nanospindles cluster on Fe core. The various hierarchical nanostructures composed of ZnO and unstable Fe nanoparticles (NPs) were successfully prepared in large scale via long-pulse-width millisecond laser ablation of Fe/Zn alloy target with suitable molar ratio immersed in anhydrous ethanol solution at room temperature and room pressure. In particular, the formation mechanism of flocky Fe@ZnO core-shell nanospheres (Fe@ZnO CSNSs) under laser ablation in liquid that constructed by unstable nanophase Fe core and stable phase ZnO QDs were proposed. As for the formation of such nanostructure, the condensation of Fe and Zn from the homogeneous metal nanodroplets after long-pulse-width laser ablation resulted in the first formation of unstable nanophase Fe core due to their huge gap in melting point. Then the subsequent diffusion and solidification of Zn atoms and oxidization process of Zn in the liquid media lead to the appearance of ZnO QDs outside the Fe core. The Fe@ZnO CSNSs were further used for the photocatalytic degradation of aromatic dye Rhodamine B (RhB). The results show that the Fe@ZnO CSNSs display quite good performance on the photocatalytic degradation of the RhB molecules under natural light irradiation with a power density around 100 mW/cm2 at 25 °C. The photocatalytic reduction of RhB is about 66.1%, 89.8%, and 94.1% after natural light irradiation for 5 min, 10 min and 20 min, respectively. The effective separation of photogenerated carriers due to the unique structure and absorption of organic molecules in the Fe@ZnO CSNSs together enhances the photocatalytic activity in the degradation of RhB. These multifunctional Fe@ZnO CSNSs present a promising potential for the removal of aromatic dye in wastewater and other catalytic applications.

Facile Synthesis of Metastable Mg-Mn Spinel Nanoparticles for Magnesium-Ion Batteries

High energy and high density rechargeable batteries are indispensable for widespread portable electronic devices and the spreading of electric vehicles. Rechargeable Mg-ion batteries have gained much attention as promising alternatives to Li-ion batteries due to the high natural abundance, high volumetric energy density, and no dendrite formation of the Mg metal anode. While Mg-ion batteries are nowadays progressing rapidly, their practical use is still hampered by problems related to both cathode materials and electrolytes. One of the crucial problems is the very low rate capability at the cathodes due to the slow diffusion of Mg2+ ions in solids, therefore Mg-ion batteries work only at low current densities or at high temperature. Among various oxide cathode candidates for Mg-ion batteries, spinel oxides have a high redox potential and a relatively high ion-diffusivity. Especially in the common electrochemical window of electrolytes, MgMn2O4 spinel can exhibit a high theoretical capacity of 540 mAh g–1 using both Mn3+/Mn4+ and Mn3+/Mn2+ redox reactions (λ-MnO2 formation and rock-salt Mg2Mn2O4 formation reactions, respectively). However, these reactions should exhibit large polarizations because of the less reversible tetragonal-cubic phase transitions; MgMn2O4 has a tetragonal spinel structure due to the Jahn–Teller effect of Mn3+ ions, while λ-MnO2 and Mg2Mn2O4 are cubic phase. A suppression of the lattice distortion of MgMn2O4 is necessary for improving its cathode performance. Although a cubic MgMn2O4 phase is known as a metastable phase, this phase is only obtained at high-temperature or high-pressure in bulk. In this study, we aimed at synthesizing metastable cubic MgMn2O4 spinel nanoparticles under ambient conditions and applying them as cathodes for Magnesium-ion batteries.Mg-Mn spinel nanoparticles were synthesized by alcohol-reduction method[1] and hot-injection method. For the alcohol-reduction method, n-Bu4NMnO4 was reduced in anhydrous MgCl2 ethanol solution at room temperature to form fine particles. For the hot-injection method, MgCl2 and Mn(acac)3 were dissolved in anhydrous xylene solution with stearic acid and oleylamine, followed by water injection at 80ºC to form monodisperse nanoparticles. Charge/discharge tests between –1.0~1.0 V vs. Ag+/Ag was carried out using a three-electrode cell with an activated carbon anode and a 0.5 M Mg(ClO4)2/CH3CN electrolyte.The Rietveld refinements of XRD patterns suggested that the obtained samples were assigned to cubic phase Mg1–x Mn2O4, and a transformation to tetragonal phase was observed after annealing at 600ºC. Since the both methods utilize rapid nucleation reactions occurred at moderate temperature, once a meta-stable phase formed, the phase transition to more stable tetragonal phase hardly proceed. The cubic phase is obtained probably due to the rapid nucleation of cubic MgMn2O4 spinel nanoparticles at moderate temperature. According to TEM images, the primary particle size of both samples was below 10 nm, suggesting the rapid nucleation without crystal growth. However, the particles were aggregated to form large secondary particles. The electrochemical performances strongly depended on the morphology of secondary particles, therefore suppression of the aggregation is important for improving the performance. Reference: [1] H. Kobayashi, K. Yamaguchi, I. Honma, RSC Adv. 9 (2019) 36434–36439.

Acid-catalyzed reaction of ethanol and oxazepam and its pharmacological consequence

Oxazepam (OX), an anxiolytic drug in clinical use, reacts with ethanol in aqueous and anhydrous ethanol solutions and simulated gastric fluid to form 3-O-ethyloxazepam (EtOX). In simulated gastric fluid containing 30% (by volume) ethanol, approximately 9.5% of OX is converted to EtOX in 2 hr at 37°C. Studies of this report indicate that the 3-hydroxyl group of OX is substituted by ethanol to form EtOX in acidic media. Pharmacokinetic studies in rats indicate that orally administered OX and EtOX at doses of 35 and 17.5 nmole/kg are absorbed to similar extents. EtOX is eliminated at a slower rate than OX. EtOX is less active than OX in two pharmacological activity tests in mice. It is known that ethanol and OX have additive effects in the central nervous system. The results of this study suggest that ingestion of ethanol shortly before, shortly after, or simultaneously with the intake of OX may result in the formation of EtOX in the strongly acidic medium of the stomach, reducing the pharmacological effects of OX.

Simultaneous Quantification of DPPG, DEPC and Cholesterol in Propofol Liposome by HPLC-ELSD Using Alkaline Hydrolysis.

A high-performance liquid chromatography method with evaporative light-scattering detection (ELSD) was performed for simultaneous determination of dipalmitoyl phosphatidylglycerol (DPPG), dierucoyl phosphatidylcholine (DEPC) and cholesterol in propofol liposome by the pretreatment of alkaline hydrolysis (temperature, concentration of KOH anhydrous ethanol solution and reaction time were 90°C, 1mol · L-1 and 10min, respectively). The analysis was carried out on an Agilent TC-C18 column (4.6mm×250mm, 5μm) with isocratic elution of methanol and 0.1% acetic acid aqueous solution (95:5, v/v) at a flow rate of 1.0mL· min-1. The column temperature was 30°C. The drift tube temperature of the ELSD system was set at 30°C, and the pressure of carrier gas was 350KPa. The regression equation revealed a good linear relationship (r=0.9990-0.9993) during the test ranges. The RSD of stability and repeatability (n=6) was found to be less than 1.96 and 1.46%, respectively. The average recoveries ranged from 97.90 to 101.00%. The proposed method was validated and showed good precision, stability, repeatability and recovery, which indicated that the method could be readily utilized as a quality evaluation method for the determination of DPPG, DEPC and cholesterol in propofol liposome.

One-step combustion synthesis of C-Mn3O4/MnO composites with high electrochemical performance for supercapacitor

Carbon inlaid composites (C-Mn3O4/MnO) were prepared via igniting manganese acetate anhydrous ethanol solution in a beaker, and the resulting nanocomposites present homogeneous dispersion and stable property. The successful fabrication of the as-prepared samples was demonstrated by x-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). Various electrochemical measurements including cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) were carried out. The maximum specific capacitance value of the C-Mn3O4/MnO composites can reach up to 204 F g−1 at a current density of 1 A g−1, which is much higher than that of Mn3O4/MnO composites (90 F g−1). The incorporated carbon improves the electrochemical performance and effectively decreases the charge transfer resistance of the composites (0.67 Ω) compared with pure Mn3O4/MnO composites (42.4 Ω). Surprisingly, as the number of cycles increase, the specific capacitance of C-Mn3O4/MnO composites become larger with a 188.3% of the initial specific capacitance value. This study develops a novel and facile method to fabricate composites of carbon and manganic oxide which have potential application in supercapacitor.

Enhanced low-temperature NH3-SCR performance of MnOx/CeO2 catalysts by optimal solvent effect

A series of MnOx/CeO2 catalysts were prepared by modulating the solvents (deionized water (DW), anhydrous ethanol (AE), acetic acid (AA), and oxalic acid (OA) solution) with the purpose of improving the low-temperature NH3-SCR performance, broadening the operating temperature window, and enhancing the H2O+SO2 resistance. The synthesized catalysts were characterized by means of N2-physisorption, XRD, EDS mapping, Raman, XPS, H2-TPR, NH3-TPD, and in situ DRIFTS technologies. Furthermore, the catalytic performance and H2O+SO2 resistance were evaluated by NH3-SCR model reaction. The obtained results indicate that MnOx/CeO2 catalyst prepared with oxalic acid solution as a solvent exhibits the best catalytic performance among these catalysts, which shows above 80% NO conversion during a wide operating temperature range of 100–250°C and good H2O+SO2 resistance for low-temperature NH3-SCR reaction. This is related to that oxalic acid solution can promote the dispersion of MnOx and enhance the electron interaction between MnOx and CeO2, which are beneficial to improving the physicochemical property of MnOx/CeO2 catalyst, and further lead to the enhancement of catalytic performance and good H2O+SO2 resistance.

Adsorption of Methylene Blue on Mesoporous SBA‐15 in Ethanol‐water Solution with Different Proportions

The adsorption behavior of mesoporous SBA‐15 materials to methylene blue (MB) as model molecule has been studied in different proportions of ethanol‐water solution. It was found that adsorption capacity and adsorption rate of SBA‐15 to methylene blue were the best in aqueous solution and the worst in anhydrous ethanol solution, in addition, adsorption capacity and adsorption rate increase as the proportion of water increased in ethanol‐water solution. It’s interesting that the release behavior at a specific time appeared in the adsorption process of SBA‐15 to methylene blue from anhydrous ethanol solution or ethanol‐water solution. The adsorption kinetics of methylene blue (MB) on mesoporous SBA‐15 samples in different solution have been analyzed and discussed based on the composition, the morphology, the surface area, pore size distribution and adsorption/desorption measurements measured with scanning electron microscopy (SEM), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), nitrogen adsorption‐desorption and spectrophotometer technique.

Soluplus/TPGS mixed micelles for dioscin delivery in cancer therapy

Background: Dioscin has shown cytotoxicity against cancer cells, but its poor solubility and stability have limited its clinical application. In this study, we designed mixed micelles composed of TPGS and Soluplus® copolymers entrapping the poorly soluble anticancer drug dioscin.Method: In order to improve the aqueous solubility and bioactivity of dioscin, TPGS/Soluplus® mixed micelles with an optimal ratio were prepared using a thin-film hydration method, and their physicochemical properties were characterized. Cellular cytotoxicity and uptake of the dioscin-loaded TPGS/Soluplus® mixed micelles were studied in MCF-7 breast cancer cells and A2780s ovarian cancer cells. The pharmacokinetics of free dioscin and dioscin-loaded TPGS/Soluplus® mixed micelles was studied in vivo in male Sprague-Dawley rats via a single intravenous injection in the tail vein.Results: The average size of the optimized mixed micelle was 67.15 nm, with 92.59% drug encapsulation efficiency and 4.63% drug loading efficiency. The in vitro release profile showed that the mixed micelles presented sustained release behavior compared to the anhydrous ethanol solution of dioscin. In vitro cytotoxicity assays were conducted on human cancer cell lines including A2780s ovarian cancer cells and MCF-7 breast cancer cells. The mixed micelles exhibited better antitumor activity compared to free dioscin against all cell lines, which may benefit from the significant increase in the cellular uptake of dioscin from mixed micelles compared to free dioscin. The pharmacokinetic study showed that the mixed micelle formulation achieved a 1.3 times longer mean residual time (MRT) in circulation and a 2.16 times larger area under the plasma concentration–time curve (AUC) than the free dioscin solution.Conclusion: Our results suggest that the dioscin-loaded mixed micelles developed in this study might be a potential nano drug-delivery system for cancer chemotherapy.

Nasal submicron emulsion of Scutellariae Radix extract preparation technology research based on phase transfer of solute technology

Based on the demand of nasal drug delivery high drug loadings, using the unique phase transfer of solute, integrating the phospholipid complex preparation and submicron emulsion molding process of Scutellariae Radix extract, the study obtained the preparation of the high drug loadings submicron emulsion of Scutellariae Radix extract. In the study of drug solution dispersion method, the uniformity of drug dispersed as the evaluation index, the traditional mixing method, grinding, homogenate and solute phase transfer technology were investigated, and the solute phase transfer technology was adopted in the last. With the adoption of new technology, the drug loading capacity reached 1.33% (phospholipid complex was 4%). The drug loading capacity was improved significantly. The transfer of solute method and timing were studied as follows,join the oil phase when the volume of phospholipid complex anhydrous ethanol solution remaining 30%, the solute phase transfer was completed with the continued recycling of anhydrous ethanol. After drug dissolved away to oil phase, the preparation technology of colostrum was determined with the evaluation index of emulsion droplet form. The particle size of submicron emulsion, PDI and stability parameters were used as evaluation index, orthogonal methodology were adopted to optimize the submicron emulsion ingredient and main influential factors of high pressure homogenization technology. The optimized preparation technology of Scutellariae Radix extract nasal submicron emulsion is practical and stable.

Fabrication of superhydrophobic and oleophobic surface on zinc substrate by a simple method

Abstract This paper reports a simple approach for the preparation of superhydrophobic and oleophobic surface on zinc substrate. The surface was created by chemical etching and hydrothermal reaction, consisting of micro hexagonal prisms with about 4 μm in length, 0–1 μm in gap and 0.1–0.4 μm in diameter. The surface then became superhydrophobic and oleophobic with a fluoride coating, fabricated by chemically modified with perfluorooctanoic acid anhydrous ethanol solution. The effects of different process parameters, including chemical etching time and the hydrothermal temperature, on the surface morphology and wettability were examined using a scanning electron microscope (SEM) and a contact angle tester. The optimization of process parameters were obtained, namely, the chemical etching time was 90 s and the hydrothermal temperature was 95 °C. After zinc surface was treated using the optimum parameters, the results showed that the surface exhibited repellency toward distilled water and edible peanut oil with contact angles at 151.85° and 145.62°, respectively, and the sliding angle for distilled water was less than 10°.

Synthesis, X-ray structure analysis and density functional study of an unusual anhydrous 5,6-dimethylbenzo-1,3-imidazolium(H3) chloride

The heteroaromatic base 5,6-dimethylbenzo-1,3-imidazole (DMBI) proved to be a Brönsted base in an anhydrous ethanol solution, which contained fac,trans-[Ru(CO)3Cl2]2 at 55°C in air when the DMBI:Ru molar ratio was 2:1. The reaction produced colorless anhydrous single crystals of {(HDMBI)+Cl−}, C9H11ClN2, which were collected and analyzed using X-ray diffraction (XRD) techniques. A network of N–H⋯Cl hydrogen bond type interactions linking the protonated hetero-aromatic base to the chloride anions (bridging bases) stabilizes the crystal and mimics the N–H⋯Cl− interactions that play important roles in CCl channel biological systems. The shortest N⋯Cl contact distance and corresponding N–H⋯Cl angle are 3.073(3)Å and 173(3)°, respectively. The packing is also assisted by weaker C–H⋯Cl− hydrogen bond-type interactions and an extensive network of π⋯π stacking interactions involving HDMBI+ cations. Density functional calculations at the B3LYP/6-31G∗∗ and /6-311++G∗∗ levels for models of fragments of the crystal structure allowed for the evaluation of geometric parameters, hydrogen bond-type interaction formation energies, and infrared parameters for {(HDMBI)+Cl−} and {(HDMBI)+⋯Cl−⋯(HDMBI)+}.

Preparation of Oleophobic Surface on X70 Pipeline Steel

The oleophobic surface has extremely broad application prospects in industrial production and daily life. It can prevent the adhesion of materials and fouling, and prolong the service life. In this investition, an oleophobic surface on X70 pipeline steel specimen was prepared successfully by the combination of sandblasting, chemical etching, and low energy modification. The microstructure and oleophobicity of the surface were studied by scanning electron microscope (SEM), contact angle tester, and confocal microscope. The results showed that micro-nanocomposite structure on the specimen was formed after sandblasting and chemical etching of concentrated hydrochloric acid aqueous solution. The low-energy modification of perfluorooctanoic acid anhydrous ethanol solution just covered the surface, but had no obvious influence on the surface morphology. After chemical etching and low-energy modification, the specimen processed by sandblasting for 30s obtained the better oleophobicity, and the maximum contact angle between the surface and engine oil was 130°.

Effect of AlF3 seed concentrations and calcination temperatures on the crystal growth of hexagonally shaped α-alumina powders

To synthesize micro-sized and high crystalline α-alumina particles with uniformly and rapidly at low temperatures, various concentrated AlF3 seeds were added into an anhydrous ethanol solution saturated by an aluminum hydroxide starting material, gibbsite Al(OH)3. Hexagonal shaped α-alumina powders highly crystallized were observed at lower temperature of 750°C, in the ranges from 0.01–5.0mol% seed concentrations, and the α-alumina crystal growth depends on the concentrations of added AlF3 seed. When 1.0mol% AlF3 seeds were added, the largest α-alumina hexagonal crystals (average size about 4.8m after calcination at 900°C) were produced. Additionally the crystallinity and size of α-alumina particle increases linearly with the calcination temperature. The size rapidly increased with an increase of calcination temperatures to 800°C and then gradually increased up to 900°C. This result shows that crystal growth of α-alumina is affected by seed concentrations and crystallized calcination temperature.

不同有机碱对乙酰水杨酸铽配合物荧光性能的影响

Three kinds of terbium complexes solution were prepared in anhydrous ethanol solution using triethylamine( TEL),tripropylamine( TPL) and tributylamine( TBL),respectively. By characterization of UV spectra,fluorescence spectra,absolute quantum yield and fluorescence lifetime,the three types of terbium complexes have different fluorescent properties. Under the condition of same concentration,the fluorescent intensity of the three kinds of terbium complexes increases with the carbon chain length of orgainc amine increaseing. The absolute quantum yields of Tb( aspirin)3TEL,Tb( aspirin)3TPL and Tb( aspirin)3TBL using the three types of organic bases are11. 41%,12. 85% and 18. 63%,respectively. The fluorescence lifetimes in anhydrous ethanol solution are 6. 316 956 × 10-4,7. 018 974 ×10-4,and 7. 346 807 ×10-4s,respectively. The results show that organic base involved in the molecular composition of terbium complexes.

Factors Affecting Migration of Contaminants from Paper through Polymer Coating into Food Simulants

The migration of two surrogate contaminants, 1‐hydroxycyclohexyl‐1‐phenyl ketone (184) and benzyldimethyl ketal (651), from different paper into different food simulant (10% ethanol, 95% ethanol and isooctane) through different polymer coating low density polyethylene (LDPE) and polypropylene (PP) was studied. The paper samples were spiked with anhydrous ethanol solution containing the two surrogates and were dried using vacuum dry oven with vacuum degree 0.01 MPa and temperature 55°C and then subjected to migration experiments by using single‐sided contact method at 20°C. The concentration of surrogates in 10% ethanol, 95% ethanol and isooctane food simulants were determined by gas chromatography with flame ionization detector after predisposal. Effect factors on migration were discussed from different aspect such as food simulant, paper property, thickness of polymer coating and type of polymer coating. The results showed that the migration rate was faster in fatty food simulant 95% ethanol and isooctane than in aqueous food simulant 10% ethanol, a thicker LDPE coating delayed the migration process of contaminant, paper with lower density and higher porosity would increase migration speed and the barrier property of PP was far away higher than that of LDPE, even if the thickness of LDPE was thicker a lot than PP. Copyright © 2012 John Wiley & Sons, Ltd.

New Methodology for pH Measurements in Fuel Ethanol Using Glass Electrode

Abstract Studies carried out with glass electrode in anhydrous ethanol and ethanol-water solutions for measuring pH values have shown that this parameter depends on the solution composition, the contact time with the solution, the utilized temperature, and the type of electrolyte used. It was also observed that the glass electrode behavior in an acid medium differs from an alkaline medium. These studies provided correction factors for pH values from 2 to 12, allowing the realization of proper measurements of the hydrogen ionic activity in the ethanol-water and anhydrous ethanol solutions. However, these correction factors could not be applied to the fuel ethanol. Alternatively, a new method was developed for the correction of the pH values, which can be applied in hydrous and anhydrous fuel ethanol samples.