Mesoporous Nickel–Alumina Catalysts for Hydrogen Production by Steam Reforming of Liquefied Natural Gas (LNG)

Recent progress on the mesoporous nickel–alumina catalysts for hydrogen production by steam reforming of liquefied natural gas (LNG) was reported in this review. A number of mesoporous nickel–alumina composite catalysts were prepared by a single-step surfactant-templating method using cationic, anionic, and non-ionic surfactant as structure-directing agents for use in hydrogen production by steam reforming of LNG. For comparison, nickel catalysts supported on mesoporous aluminas were also prepared by an impregnation method. The effect of preparation method and surfactant identity on physicochemical properties and catalytic activities of mesoporous nickel–alumina catalysts in the steam reforming of LNG was investigated. Regardless of preparation method and surfactant identity, nickel oxide species were finely dispersed on the surface of mesoporous nickel–alumina catalysts through the formation of surface nickel aluminate phase. However, nickel dispersion and nickel surface area of mesoporous nickel–alumina catalysts were strongly affected by the preparation method and surfactant identity. It was found that nickel surface area of mesoporous nickel–alumina catalyst served as one of the important factors determining the catalytic performance in hydrogen production by steam reforming of LNG. Among the catalysts tested, a mesoporous nickel–alumina composite catalyst prepared by a single-step non-ionic surfactant-templating method exhibited the best catalytic performance due to its highest nickel surface area.     

Profiling of phospholipids in lipoproteins by multiplexed hollow fiber flow field-flow fractionation and nanoflow liquid chromatography–tandem mass spectrometry

This study describes a coupled analytical method to carry out the systematic profiling of phospholipids (PLs) in high-density lipoproteins (HDL) and low-density lipoproteins (LDL) from human blood plasma. HDL and LDL of healthy human plasma samples were separated by size and collected on a semi-preparative scale using multiplexed hollow fiber flow field-flow fractionation (MxHF5). Phospholipid mixtures contained in the resulting HDL and LDL fractions were analyzed by shotgun nanoflow liquid chromatography–tandem mass spectrometry (nLC–ESI-MS–MS). We utilized a dual scan method for the separation and simultaneous characterization of complicated PL mixtures by nLC–ESI-MS–MS, such that phosphatidylcholine (PC) and phosphatidylethanolamine (PE) molecules were detected in positive ion mode in a first LC run. In a second LC run, phosphatidylinositol (PI), phosphatidylglycerol (PG), and phosphatidic acid (PA) were detected in negative ion mode. In this study, a total of 56 PLs from HDL and 52 PLs from LDL particles were characterized by their molecular structures from data dependent collision-induced dissociation (CID) experiments, and their relative abundances were compared.     

Simultaneous qualitative and quantitative method using liquid chromatography selected reaction monitoring-triggered quantitation-enhanced data-dependent tandem mass spectrometry for the identification and classification of amphetamine-type stimulant abusers in human urine

Amphetamine (AP) and amphetamine‐type stimulants, methamphetamine (MA) and N,N‐dimethylamphetamine (DMA), are known as central nervous system stimulants, and their abuse throughout the world has recently increased. Since it is difficult to physically distinguish among AP, MA and DMA, analysts may not be aware of what abusers have administered. In this study, following the detection of specific metabolites of AP, MA and DMA as biomarkers in abuser urines, a rapid and sensitive method was developed for the identification and classification of AP‐type stimulants abusers. After the simple filtration of the urine samples, the samples were directly analyzed using a liquid chromatography/tandem mass spectrometry system with selected reaction monitoring (SRM)‐triggered quantitation‐enhanced data‐dependent MS/MS (QED‐MS/MS) for the simultaneous qualitative and quantitative analysis of p‐hydroxy AP, p‐hydroxy MA, p‐hydroxy DMA, AP, MA, DMA and DMA N‐oxide. The determination of p‐hydroxy AP, p‐hydroxy MA, AP, MA, DMA and DMA N‐oxide was accurate and reproducible, with the limits of quantitation of 5 ng/mL in urine. When applied to the urine samples of suspected AP‐type stimulants abusers, the abused drugs were precisely identified between MA and DMA abusers. Copyright © 2010 John Wiley & Sons, Ltd.     

Palladium‐catalyzed carbonylative cyclization of 3‐bromoallyl alcohols leading to furan‐2(5H)‐ones

3‐Bromoallyl alcohols are carbonylatively cyclized under carbon monoxide pressure in toluene in the presence of a catalytic amount of Pd(OAc)₂ and PPh₃ along with Na₂CO₃ to give furan‐2(5H)‐ones in good yields. Copyright © 2012 John Wiley & Sons, Ltd.     

High‐performance holographic polymer‐dispersed liquid crystals by incorporating hyperbranched polymers

A minute amount (0.01–0.3 wt %) of ally isocyanate functionalized hyperbranched 2,2‐bis (hydroxymethyl) propionic acid (bis‐MPA) polyester‐16‐hydroxyl (HBP) was incorporated covalently into polyurethane acrylate‐based holographic polymer dispersed liquid crystals (HPDLCs), and its effects on the compound viscosity, grating kinetics, morphology, diffraction efficiency (DE), and electro‐optical properties of the HPDLC films were examined. HBP at low concentrations (0.01–0.05%) reduced the compound viscosity and domain size of liquid crystal (LC) significantly and augmented the cure rate and saturation DE by up to threefold compared to the HBP‐free compound. At high concentrations (0.10 and 0.30%), HBP increased the compound viscosity and decreased the rate of grating formation, giving rise to distorted LC‐polymer interfaces, which caused a significant decrease in the threshold and operating voltages. The rise and decay time showed a minimum and maximum, respectively, when the compound viscosity was a minimum at 0.03% HBP. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Preparation and characterization of a nanoscale poly(vinyl alcohol) fiber aggregate produced by an electrospinning method

Nanoscale poly(vinyl alcohol) (PVA) fiber (100–500 nm) aggregates were prepared with an electrospinning technique. Additionally, a chemical crosslinking method was used to crosslink the nanoscale PVA fiber aggregates. Differential scanning calorimetry, wide‐angle X‐ray diffraction, and scanning electron microscopy techniques were employed to characterize the PVA fiber aggregates. The different crosslinking densities of the PVA fiber aggregates were obtained through the control of the weight percentage of glyoxal to PVA. The crosslinking densities due to heat treatment and chemical crosslinking were studied. The influence of heat treatment could be neglected in contrast to chemical crosslinking when the curing temperature was 120 °C. The primary factor that affected the crosslinking density was the volume of the chemical crosslinking agent. The results showed that the properly crosslinked PVA fiber aggregates had better antiwater solubility and mechanical properties than the noncrosslinked PVA fiber aggregates. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1261–1268, 2002     

Amperometric ion sensors based on laser-patterned composite polymer membranes

A polymer membrane for the selective amperometric transfer and sensing of molecular ions has been designed and characterised. The membrane was formed from two polymer layers, a supporting film of polyethylene terephthalate on which an electrolyte film containing polyvinylchloride is cast. The polyester layer has a laser-etched pattern of circular micro-holes in one region. These hole structures are arranged in a rectangular geometry and measure 22 μm in diameter with separation distances of 105 μm and 120 μm. The polyvinylchloride underlayer is a composite system comprised of a 2-nitrophenyl octyl ether plasticising solution containing an electrolytic salt of tetrabutylammonium tetrakts-(4-chlorophenyl)borate. In this way, an array of micro-interfaces between an analyte solution and a PVC gel electrolyte is formed and used as a liquid|liquid interface for the amperometric monitoring of ion transfer reactions. The membrane was characterised in terms of the voltammetric response to choline transfer. The study includes an examination of the fabrication methodology, materials composition and membrane structure.     

Ultrafast laser ablation of indium tin oxide thin films for organic light-emitting diode application

Ultrafast laser ablation of ITO thin film coated on the glass has been investigated as a function of laser fluence as well as the number of laser pulses. The ablation threshold of ITO thin film was found to be 0.07 J/cm² that is much lower than that of glass substrate (about 1.2–1.6 J/cm²), which leads to a selective ablation of ITO film without damage on glass substrate. The changes in the electrical resistance and morphology of ablated trench of ITO electrode were found to be strongly dependent on the processing conditions. We present the performance of organic light-emitting diodes (OLED) fabricated with ITO electrode patterned by ultrafast laser ablation.