Dichloride Solution Research Articles

Water-borne, durable and multicolor silicon nanoparticles/sodium alginate inks for anticounterfeiting applications

Recently, water-borne fluorescent inks have attracted extensive attention in anti-counterfeiting applications due to their convenient implementation and eco-friendliness. However, due to poor service durability, the latent authorization information from the inks is easily damaged, and even disappears when encountering water. Moreover, most of the existing fluorescent inks are monochromic, toxic, and allergic to skin, thus are unsuitable for their sustainability during real-life applications. Herein, this work presents environment-friendly, durable, and multicolor fluorescent anti-counterfeiting silicon nanoparticles (SiNPs)/sodium alginate (SA) inks. The multicolor SiNPs are synthesized by a one-pot method with defined morphologies and optical properties. Subsequently, SA is employed as the binder to prepare the fluorescent inks with optimized rheological properties. Practicability results show that the SiNPs/SA inks not only exhibit excellent printability, but also impart authentic information with superior covert performance. More notably, spraying solution of calcium dichloride can further improve fluorescent fastnesses of the SiNPs/SA inks by ionic crosslinking.

Fabrication and performance of a superhydrophobic fluorine-modified porous silicon based on photocatalytic hydrosilylation

Porous silicon was widely used in displays, optical sensors, and biological imaging due to its high surface areas, adjustable microstructure, large adsorption capacity and excellent optical performance. Unfortunately, there are numerous reactive silane groups on the freshly etched porous silicon surface, which are susceptible to oxidization in the air, thereby affecting the optical performance and stability of porous silicon. This study provides an efficient strategy of using photocatalytic reaction to graft dodecafluoroheptyl methacrylate to freshly prepared n-type porous silicon surface, thereby generating a fluorine-modified porous silicon with high stability and superhydrophobic surface. The structure and composition of porous silicon before and after modification were analyzed by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy-energy dispersive spectrometer (SEM-EDS) and X-ray photoelectron spectroscopy (XPS). The effects of UV light, reactant mass fraction and reaction time on the surface properties of porous silicon were studied by water contact angle (WCA) and photoluminescence (PL). The results indicated that the dodecafluoroheptyl methacrylate was successfully grafted onto n-type porous silicon surface by photocatalytic reaction. The superhydrophobic and luminescent porous silicon was prepared by reacting 40 min in a dichloride solution containing 10 wt% dodecafluoroheptyl methacrylate under UV light. The WCA of the fluorine-modified porous silicon surface could reach 153° and had good photoluminescence intensity. This modified porous silicon surface had great stability in alkaline and air environment. After treated with alkaline droplets for 30 min, the WCA of modified porous silicon could maintain above 150° and had good photoluminescence. And under room temperature within a week, the porous silicon surface still showed great hydrophobic properties and photoluminescence intensity. In addition, the modified porous silicon has different responsiveness to ethanol solutions of different concentrations, which could be applied to alcohol sensors and has great development prospects. • A fluorine-modified porous silicon was synthesized by a simple and efficient photocatalytic reaction. • The WCA of the fluorine-modified porous silicon surface could reach 153°. • The photoluminescence intensity showed a great stability in alkaline and air environment.

Activity standardisation of 223Ra

We report here on the primary activity standardisation of a223Ra dichloride solution in equilibrium with its decay daughters. Both the triple-to-double-coincidence-ratio (TDCR) method with an in-house TDCR detector and the CIEMAT-NIST efficiency tracing (CNET) technique with a commercial counter were used. The liquid scintillation efficiencies for both methods are about 6 while the activities they predict with about 0.4% relative standard uncertainty agree within 0.15%. For backup, the solution was also standardised with 4πγ NaI(Tl) integral counting with a well-type NaI(Tl) detector, and efficiencies computed by Monte Carlo simulations using the GEANT code. This simple technique, unused previously for this nuclide, yielded an activity concentration compatible with, but 1% lower than, the one determined by liquid scintillation counting.

Синтез новых производных 6-гидроксипиримидин-4(3Н)-она

In this paper, 6-hydroxypyrimidine-4 (3Н)-one derivatives are considered as promising syntones for the creation of new biologically active substances. This is useful since the pyrimidine fragment is a structural component of nucleic acid bases (cytosine, thymine, uracil), uric and orotic acids, coenzymes (flavins and xanthins), a number of vitamins (folic acid, thiamine, pyridoxine, riboflavin). It is worth noting that the pharmaceutical market is widely represented with antitumor (methotrexate, imatinib, tegafur); antiviral (stavudine, zalcitabine, lamivudine, zidovudine, acyclovir, idoxuridine); immunostimulatory (isophone) and sedative drugs (phenobarbital, sodium ethaminal) based on compounds including the pyrimidine cycle. The purpose of the present work is to develop a method for producing new 2,3-diphenyl-5-(alkyl/ phenyl)-6-hydroxypyrimidin-4(3Н)-ones, proving their structure and individuality by NMR spectroscopy and mass spectrometry, elemental analysis and thin-layer chromatography. As a method of producing new 6-hydroxypyrimidin-4(3Н)-ones, a method of condensing N-phenyl-benzenecarboxymidamide with 2-substituted propanedioyldichlorides in the medium of an aprotic non-polar solvent – o-xylene is proposed. The desired products are isolated from the reaction mass using solvent distillation and a reprecipitation method. It was found that maximum yields are achieved with constant stirring of a suspension of N-phenylbenzenecarboxymidamide with a solution of 2-substituted propanedioyl dichloride in o-xylene and further heating of the reaction mass at 144 °C for 4 hours. The individuality of the synthesized compounds was confirmed by thin layer chromatography on Sorbfil® plates in the methanol-dichloroethane (1:9) system, and their structure was proved using modern physicochemical analysis methods: proton magnetic resonance spectroscopy, NMR С13 spectroscopy, mass spectroscopy and elemental analysis.

Diffusion Metrics for Staging Pancreatic Fibrosis and Correlating With Epithelial‐Mesenchymal Transition Markers in a Chronic Pancreatitis Rat Model at 11.7T MRI

Chronic pancreatitis (CP) is characterized by pancreatic fibrosis, in which a epithelial-mesenchymal transition (EMT)-like process is observed. However, few noninvasive approaches have been reported to evaluate pancreatic fibrosis and EMT in an animal model based on diffusion imaging. To evaluate pancreatic fibrosis in CP by conventional diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI) and then explore the correlation between diffusion parameters and the EMT markers in an animal model. Prospective controlled imaging histological correlation. Forty-five rats with CP induced by injecting dibutyltin dichloride solution and 10 normal rats comprised the control group. 11.7T MR, diffusion imaging with 10 b-values. Apparent diffusion coefficient (ADC), IVIM-associated perfusion fraction (f), pseudodiffusion coefficient (D*), diffusion coefficient (D), DKI-associated mean kurtosis (MK), and mean corrected diffusion coefficient (MD) were quantitatively measured and correlated with pancreatic fibrosis stages as well as the EMT markers E-cadherin and α-smooth muscle actin (α-SMA) expression. The discriminative performance of diffusion parameters for staging fibrosis was compared. Spearman's correlation, Student's t-test, and a receiver operating characteristic curve was conducted for statistical analysis. ADC, D, and MD (r = -0.637, -0.688, and -0.535; P < 0.001) were negatively correlated with pancreatic fibrosis staging, but MK (r = 0.740, P < 0.001) had a positive correlation. ADC, D, MD, and MK were significantly correlated with α-SMA (r = -0.684, -0.728, -0.627, and 0.721, all P < 0.001), while MK was significantly correlated with E-cadherin (r = -0.606, P < 0.001). The area under the curve (AUC) was not significantly different (P > 0.05) among ADC (0.797, 0.816, 0.873), D (0.862, 0.810, 0.895), MD (0.767, 0.772, 0.801), and MK (0.836, 0.893, 0.951) for F1 or greater, F2 or greater, and F3 pancreatic fibrosis separately. ADC, D, MD, and MK were helpful for assessing pancreatic fibrosis staging, and these diffusion parameters were also significantly correlated with the expression of EMT markers in pancreatic fibrosis. 2 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;52:197-206.

Crystallographic Structural Elucidation of E. coli HU and a Four‐Way Junction

E. coli histone‐like HU protein binds with high affinity to DNA recombination intermediates, such as the Holliday junction, to facilitate prokaryotic DNA transcription, compaction, recombination, and replication. While previous Förster resonance energy transfer (FRET) studies have determined possible structural models of HU‐junction interaction, X‐ray crystallographic data is needed to confirm those models. Studies have shown that crystals can be obtained with a dodecamer junction complex. However, we believe that HU can also be successfully crystallized with J20, that is, a junction with 20 base pairs per strand. We believe that 20 base pairs per arm is sufficient in limiting the flexibility of our junction. Our investigation aims to determine the most favorable conditions for HU‐J20 crystallization by using various solvents, pH, and viscosities. In our study, we show that our HU samples are pure, nuclease‐free, and bind with high affinity to J20. In addition, we show that our J20 samples are at least 90% properly annealed via a non‐denaturing polyacrylamide gel. Moreover, we have observed the formation of small crystals in a few of our wells, primarily around pH 8.5 in 20% polyethene glycol with 0.2 M ammonium chloride, and 0.005 M calcium dichloride. Going forward, we will screen around our successful conditions with higher protein concentrations. We will also use magnesium dichloride solutions in addition to calcium dichloride solutions, as previous studies have shown that magnesium improves the stabilization of DNA. Upon the development of crystals, we hope to solve the structure of HU‐J20 via diffraction.Support or Funding InformationAmerican Society of Biochemistry and Molecular Biology Undergraduate Research Award, Wesleyan Math and Science Scholars Program, Wesleyan UniversityThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Determination of Paraquat Dichloride from Water Samples Using Differential Pulse Cathodic Stripping Voltammetry

Paraquat dichloride commonly used as herbicide was determined by differential pulse cathodic stripping voltammetry technique. Experimental parameters, such as pH, accumulation time, accumulation potential and initial potential were optimized. In this analysis, paraquat dichloride exhibited a well-defined tworeduction peaks at −0.35 and −0.90 V in the pH range from 2.0 to 12.0. The 0.04 mol L–1 BR buffer at pH 2.0 was found a suitable medium for electroanalytical determination of the paraquat dichloride. Interfering ions effect was not significant. Linear calibration plots for standard solutions of paraquat dichloride were obtained in the range of 0.25 to 1.75 × 10–6 mol L–1. Detection limit was 3.66 × 10–8 mol L–1. The optimized parameters were effectively applied for the determination of commercial paraquat dichloride and in artificial samples. Artificial samples were prepared by spiking paraquat dichloride into tap water and drinking water dispenser samples. The recovery value was 90.5% in drinking water dispenser samples and 91.7% in tap water samples at the concentration range of 1.00 × 10–6 to 1.75 × 10–6 mol L–1.

Semi-aromatic polyamide-based nanocomposites: I. in-situ polymerization in the presence of graphene oxide

In-situ interfacial polymerization method was employed to synthesize nanocomposites based on a semi-aromatic polyamide (PA) and pristine or sulfonated graphene oxides (GO or SGO, respectively). The PA chains were produced at the interface of a nonaqueous solution of isophthaloyl dichloride and an aqueous triethylenetetramine solution containing different amounts of GO or SGO dispersed nanosheets. The effects of SGO and pristine GO on the structure, thermal stability and dynamic mechanical and electrical properties of PA were studied. Favorable interfacial interactions between SGO and PA were confirmed using Fourier transform infrared spectroscopy and X-ray diffractometry. Consequently, SGO significantly increased the thermal stability and char residues of PA. Furthermore, adding both pristine and sulfonated GO nanosheets led to an enhancement in storage modulus and a shift in glass transition temperature of the polyamide. Finally, the facile sulfonation of GO resulted in partial reduction of the electrically insulating nanosheets and hence the electrical conductivity and dielectric constant of PA were increased by 10 and 3 times, respectively, at SGO content of 1.0 wt%.

Enhanced Photocatalytic Hydrogen Evolution from Transition-Metal Surface-Modified TiO2.

This study describes the UV solution photodeposition of several earth-abundant 3d transition metals (Co, Ni, and Cu) onto the surface of nanoparticulate TiO2. Irradiated methanolic metal dichloride solutions with suspended Degussa P25-TiO2 (1–2 wt % metal to TiO2) yield visibly colored titanias, whereas the bulk TiO2 structure is unchanged; X-ray photoelectron spectroscopy confirms that metals are present on the titania surface in either reduced metal (Cu/Cu+) or metal cation states (Co2+ and Ni2+), and UV–vis diffuse reflectance spectroscopy shows new visible absorbance features. The analyzed bulk metal contents (∼0.04–0.6 at. %, highest for copper) are lower than the nominal metal solution content. Mixed-metal solution photodeposition reactions roughly parallel observations for single metals, with copper deposition being most favored. These 3d metal surface-modified titanias show significant (∼5–15×) improvement in UV photocatalytic H2 evolution versus unmodified TiO2. H2 evolution rates as high as 85 μmol/h (8500 μmol h–1 g–1) were detected for Cu-coated TiO2 using continuous monitoring of reactor headspace gases by portable mass spectrometry. Control experiments verify the necessity of the methanol sacrificial oxidant in both metal deposition and H2 evolution. In situ metal surface deposition is quickly followed by enhanced H2 evolution relative to TiO2, but at lower levels than isolated metal surface-modified titanias. The photodeposited 3d metal species on the TiO2 surface likely act to reduce electron–hole recombination by facilitating the transfer of photoinduced TiO2 conduction band electrons to protons in solution that are reduced to H2. This study demonstrates a facile method to modify photoactive TiO2 nanoparticles with inexpensive 3d transition metals to improve photocatalytic hydrogen evolution, and it shows the utility of quantitative real-time gas evolution monitoring by portable mass spectrometry.

Rheology of Modified Wood by Means of Pure Solvent or Solution Treatments

Viscoelasticity of chemically modified Cedrus deodara by means of pure solvent or solution treatments has been evaluated using dynamic-mechanical analysis in bending mode at 30 °C. The samples are treated up to equilibrium conditions in solvents with different polarity (water, ethanol and acetone), and corresponding solutions with bifunctional chemicals (acyl dichloride and aliphatic-diamine). Then, in all cases the samples are air-dried and temperature equilibrated before to be characterized. Mechanical properties have been explored by means of stress–strain plots at different strain rate, creep and step-strain experiments. Dynamic-mechanical properties have been studied by frequency-strain spectra and E1, E2 and tanδ have been investigated. Outcomes have been compared with those of a previous paper determined for seasoned or thermocured wood. The samples treated with the pure solvents exhibit an improvement of mechanical properties, due to the extraction of low molecular weight compounds acting as plasticizers of the lignin-based matrix: an increase of the elastic modulus, a reduction of the compliance and longer stress-relaxation time are observed. For the samples treated with the solutions of dichloride or diamine, the viscoelasticity behaviour is the resultant of plasticizers extraction and cross-linking of the polymeric matrix by means of the bifunctional reagents.

Preparation of Porous Core-Shell Poly L-Lactic Acid/Polyethylene Glycol Superfine Fibres Containing Drug.

In this paper, poly L-lactic acid (PLLA) blended with polyethylene glycol (PEG) was dissolved in methylene dichloride solution as the shell solution, and rapamycin (RAPA), was encapsulated inside the core of PLLA micro/nano fibres as a model drug. The effects of the blending ratio of PLLA to PEG, the concentration of the electrospinning solution, the voltage, the flow rate, and the encapsulation efficiency were studied. Uniform and porous RAPA-Loading PLLA fibres were obtained when the ratio of PLLA to PEG was 7/3, the concentration of PLLA was 3%, the applied voltage was 7.5 kV, and the pump speed was V(core) = 0.1 mL/h, V(shell) = 1 mL/h, repectively. The average diameter of PLLA fibres increased with the gradual increase in PLLA concentration. FTIR results showed that RAPA was successfully encapsulated into the core-co-shell PLLA fibres. Meanwhile, the RAPA-loading of coaxial electrospun PLLA fibres was significantly higher than that of the blending electrospun fibres. It was also found that the porous core-shell PLLA/PEG blending superfine fibres could regulate the appearance of pore on the surface of superfine fibres by adjusting the electrospinning parameters. The porous PLLA/PEG blending fibres can be used as drug carriers and, to improve the single way of drug release depending on the degradation of shell material to meet different need. It will be a remarkable breakthrough in the area for sustained and controlled release drug delivery system.

Digital Microfluidic System with Vertical Functionality

Digital (droplet) microfluidics (DµF) is a powerful platform for automated lab-on-a-chip procedures, ranging from quantitative bioassays such as RT-qPCR to complete mammalian cell culturing. The simple MEMS processing protocols typically employed to fabricate DµF devices limit their functionality to two dimensions, and hence constrain the applications for which these devices can be used. This paper describes the integration of vertical functionality into a DµF platform by stacking two planar digital microfluidic devices, altering the electrode fabrication process, and incorporating channels for reversibly translating droplets between layers. Vertical droplet movement was modeled to advance the device design, and three applications that were previously unachievable using a conventional format are demonstrated: (1) solutions of calcium dichloride and sodium alginate were vertically mixed to produce a hydrogel with a radially symmetric gradient in crosslink density; (2) a calcium alginate hydrogel was formed within the through-well to create a particle sieve for filtering suspensions passed from one layer to the next; and (3) a cell spheroid formed using an on-chip hanging-drop was retrieved for use in downstream processing. The general capability of vertically delivering droplets between multiple stacked levels represents a processing innovation that increases DµF functionality and has many potential applications.

Analysis of metabolic characteristics in a rat model of chronic pancreatitis using high-resolution magic-angle spinning nuclear magnetic resonance spectroscopy.

Pathological and metabolic alterations co-exist and co-develop in the progression of chronic pancreatitis (CP). The aim of the present study was to investigate the metabolic characteristics and disease severity of a rat model of CP in order to determine associations in the observed pathology and the metabolites of CP using high-resolution magic-angle spinning nuclear magnetic resonance spectroscopy (HR-MAS NMR). Wistar rats (n=36) were randomly assigned into 6 groups (n=6 per group). CP was established by administering dibutyltin dichloride solution into the tail vein. After 0, 7, 14, 21, 28 and 35 days, the pancreatic tissues were collected for pathological scoring or for HR-MAS NMR. Correlation analyses between the major pathological scores and the integral areas of the major metabolites were determined. The most representative metabolites, aspartate, betaine and fatty acids, were identified as possessing the greatest discriminatory significance. The Spearman’s rank correlation coefficients between the pathology and metabolites of the pancreatic tissues were as follows: Betaine and fibrosis, 0.454 (P=0.044); betaine and inflammatory cell infiltration, 0.716 (P=0.0001); aspartate and fibrosis, −0.768 (P=0.0001); aspartate and inflammatory cell infiltration, −0.394 (P=0.085); fatty acid and fibrosis, −0.764 (P=0.0001); and fatty acid and inflammatory cell infiltration, −0.619 (P=0.004). The metabolite betaine positively correlated with fibrosis and inflammatory cell infiltration in CP. In addition, aspartate negatively correlated with fibrosis, but exhibited no significant correlation with inflammatory cell infiltration. Furthermore, the presence of fatty acids negatively correlated with fibrosis and inflammatory cell infiltration in CP. HR-MAS NMR may be used to analyze metabolic characteristics in a rat model of different degrees of chronic pancreatitis.

Rapid Chemical Bath Depositions and Properties of SnS Films

Tin sulfide films were deposited from an aqueous solution of tin dichloride, thiacetamide, and disodium citrate. X-ray diffraction, atomic force microscopy, ultraviolet–visible spectrophotometry, and electrical measurement were used to characterize the films. The films directly deposited at 70 and 80 °C for 1 and 2 h showed thicknesses of 70–400 and 120–650 nm, respectively. But the deposition at 40 °C for 1 h (nucleation step) made the films subsequently deposited at 60–80 °C denser and thicker (∼1600–7500 nm) than directly deposited films. Average transmittances of the films in UV–visible range decrease with increase in the thickness and are only in range of 0.33–2.3% for the films deposited with the nucleation step. The band gap energies of the films estimated from the transmittance spectra are in the range of ∼1.37–1.55 eV. Moreover, the films are p-type conductive. The electrical resistance and carrier mobility are in the ranges of 0.3–1.4 × 105 Ω cm and 0.77–1.56 cm2 (V s)−1, respectively. The films deposited with the nucleation step show lower resistance and higher carrier mobility than those deposited without nucleation because of their denser film microstructure and larger film thickness.

Optical and electrical properties of pure and Sn4+-doped n-SnS films deposited by chemical bath deposition

Pure and Sn4+-doped SnS films with different S/Sn molar ratio were fabricated by chemical bath deposition from the solution of tin dichloride, thiacetamide, and triammonium citrate. The deposited films were characterized by X-ray diffraction, scanning electron microscopy, ultraviolet-visible spectrophotometry, photoluminescence spectrophotometry, and electrical conduction measurement. The effect of S/Sn molar ratios and Sn4+-doping on the properties of the films was investigated. When S/Sn molar ratio in bath solution was designed as 0.55–0.85, the S/Sn ratios in the films were ~0.54–0.83. The pure films showed electrical resistivity of ~26.2–71.3kΩcm, decreasing as decreasing S/Sn ratio. The Sn4+-doping further obviously decreased the resistivity of the films to ~1.5–9.6kΩcm. The films had thicknesses of ~470−650nm and average transmittances of ~48.9−71.4% in the wavelength range of 290−1000nm. The direct and indirect optical band gaps estimated from the transmittance and reflectance spectra equaled to ~1.25−1.83eV and ~1.1−1.65eV, respectively. The average transmittances and band gap values increased as decreasing S/Sn ratio and doping Sn4+-cation.

Factors affecting catalytic destruction of H2O2 by hydrogenation and decomposition over Pd catalysts supported on activated carbon cloth (ACC)

Destruction of hydrogen peroxide by its decomposition and hydrogenation over Pd catalysts supported on activated carbon cloth has been investigated. The catalysts were prepared by the impregnation method using acidic solution of palladium dichloride (PdCl2) as a metal precursor. The reactions were performed batchwise in a Parr stainless steel autoclave. Tests were run at room temperature using either methanol or water as a reaction medium. The effects of oxidation pre-treatment of the support with different acids (nitric and acetic acid), the heat treatment of the catalysts in different atmospheres (H2 and air), and Pd content on the final properties and H2O2 destruction activity of the catalysts were investigated. The results indicated that oxygen-containing surface functional groups have an important role in determining the physicochemical properties and H2O2 destruction activity of the catalysts. In fact, the presence of these groups stabilizes H2O2 in the solution and reduces its decomposition and hydrogenation. Furthermore, the presence of the oxidized state of Pd (PdO) in the catalyst makes it less active in H2O2 decomposition when compared to the corresponding zero valences (Pd0) catalyst. Using water instead of methanol dramatically increased the H2O2 decomposition.

Preparation and Study of Pd Catalysts Supported on Activated Carbon Cloth (ACC) for Direct Synthesis of H2O2 from H2 and O2

Activated carbon cloths (ACCs) were used as supports for Pd catalysts. The catalyst preparation was carried out by the impregnation method using acidic solution of palladium dichloride (PdCl2) as metal precursor. The effects of the oxidation state of the loaded metal, heat treatment of the catalysts in different atmosphere (H2, air) at different temperatures and surface chemistry of the support on the catalyst characterizations and the catalytic activities were investigated. Wet oxidation of ACC was done by nitric acid in order to induce oxygen-containing surface functional groups. Surface chemistry of the support and oxidation state of the metallic phase was investigated by means of XPS, TPD, SEM, DTA and TGA tests. Direct synthesis of hydrogen peroxide from H2 and O2 was performed batch wise in a stainless steel autoclave. The reactions were conducted under high pressure (38 bar) at 0 °C and methanol was used as reaction medium. The direct synthesis results showed that the oxygen-containing surface functional groups increase the selectivity of the catalysts by reducing the rate of water production. Existence of the oxidized state of Pd (PdO) also makes the catalyst more selective than the corresponding zerovalent state (Pd0). PdO affected on selectivity by increasing the rate of H2O2 production and reducing the amount of production of water, simultaneously.

Preparation and characterization of CuInS2nanocrystals for photovoltaic materials

Copper indium disulphide (CIS) nanocrystals (NCs) were prepared using a one-pot synthesis. The stoichiometry was optimized based on its current density as measured by photoelectrochemical (PEC) experiments at interfaces between NC films deposited on ITO and 0.1 M methyl viologen dichloride (MV(2+)) solution. This method also offers insight into the kinetics of the photoreaction. A copper poor sulphur rich starting ratio was found to produce a copper-rich, indium-poor and slightly sulphur rich material. Further NC characterization was performed with SEM and TEM to investigate the morphology and crystallinity of the 30-70 nm NCs. The oxidation states of the individual elements were determined to be I, III, and 2- for Cu, In and S, respectively. Characteristics of optimal as-prepared NCs were found to be compatible among high functioning absorbing layers.

Growth of SnO2 crystalline thin films by mist chemical vapour deposition method

AbstractSingle crystalline tin oxide (SnO2) thin films, as a candidate for next generation novel and multifunctional transparent devices, have been grown by the mist chemical vapour deposition (CVD) method. Using water solution of tin dichloride as a source precursor, which was ultrasonically atomized to form mist particles being transferred to the reaction area by a carrier gas, the mist CVD allows safe and cost‐effective growth of high‐quality single crystalline films on sapphire substrates. The carrier concentration and mobility were 1.9×1017 cm‐3 and 55 cm2/Vs, respectively, which were comparable to those of SnO2 films grown by molecular beam epitaxy. Growth of safe materials such as oxides by environmental‐friendly technology, as we demonstrated in this paper, is one of the targets to which future compound semiconductor technology should be directed. (© 2011 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Heterogeneous Reactivity of Suspended Pirimiphos-Methyl Particles with Ozone

Pirimiphos-methyl (PMM) is a widely used pesticide that can be released into the atmosphere in the gas phase and the condensed phase. The reaction of suspended PMM particles with ozone is investigated using an online vacuum ultraviolet photoionization aerosol time-of-flight mass spectrometer (VUV-ATOFMS) and a scanning mobility particle sizer (SMPS). The reactions are conducted in an 180 L reaction chamber. The identification of particulate products detected with VUV-ATOFMS is proposed on the basis of GC-MS analysis of PMM ozonation products in methylene dichloride solution. The heterogeneous reactive rate constant of PMM with azelaic acid as matrix under room temperature (293 +/- 2 K) is (1.97 +/- 0.25) x 10(-17) cm(3) molecules(-1) s(-1). The corresponding lifetime at 100 ppbv of ozone is 5.2 +/- 0.66 h, and the reactive uptake coefficient (gamma) for ozone on PMM particles is (8.5 +/- 1.1) x 10(-4). Additionally, ozonation of PMM vapor is conducted, and the rapid formation of secondary organic aerosol (SOA) is observed in the homogeneous ozonation of gas-phase PMM. The experimental results indicate that ozone is an important atmospheric oxidant for the transformation of PMM in the atmosphere.