Global XPS (X-ray photoelectron spectroscopy) market is expected to reach USD 712.4 million by 2022, according to a new study by Grand View Research Inc. Growing application of XPS technology in different industries such as healthcare, semi conductors, aerospace, automotives, and electronics along with rising demand for research and development across all these industries is expected to drive the XPS market over the forecast period. In addition, rising popularity of hyphenated technologies and other technological advancements such as hard X-ray photoelectron spectroscopy (HAXPES) has prompted the growth of the X-ray photoelectron spectroscopy market. The ability of XPS to accurately identify contamination in the provided sample is also expected to contribute towards boosting usage rates. Rising demand for XPS technique for drug safety and medical research is expected to serve the market as a future growth opportunity. Presence of supportive government initiatives such as the "Safe Use ...
In this study, we have developed a sensitive and selective glucose sensor using novel CuO nanosheets which were grown on a gold coated glass substrate by a low temperature growth method. X-ray differaction (XRD) and scanning electron microscopy (SEM) techniques were used for the structural characterization of CuO nanostructures. CuO nanosheets are highly dense, uniform, and exhibited good crystalline array structure. X-ray photoelectron spectroscopy (XPS) technique was applied for the study of chemical composition of CuO nanosheets and the obtained information demonstrated pure phase CuO nanosheets. The novel CuO nanosheets were employed for the development of a sensitive and selective non-enzymatic glucose sensor. The measured sensitivity and a correlation coefficient are in order 5.20 × 102 µA/mMcm2 and 0.998, respectively. The proposed sensor is associated with several advantages such as low cost, simplicity, high stability, reproducibility and selectivity for the quick detection of glucose.
We report the formulation of novel composite nanoparticles that combine the high transfection efficiency of cationic peptide-DNA nanoparticles with the biocompatibility and prolonged delivery of polylactic acid-polyethylene glycol (PLA-PEG). The cationic cell-penetrating peptide RALA was used to condense DNA into nanoparticles that were encapsulated within a range of PLA-PEG copolymers. The composite nanoparticles produced exhibited excellent physicochemical properties including size |200 nm and encapsulation efficiency |80%. Images of the composite nanoparticles obtained with a new transmission electron microscopy staining method revealed the peptide-DNA nanoparticles within the PLA-PEG matrix. Varying the copolymers modulated the DNA release rate |6 weeks in vitro. The best formulation was selected and was able to transfect cells while maintaining viability. The effect of transferrin-appended composite nanoparticles was also studied. Thus, we have demonstrated the manufacture of composite
TY - JOUR. T1 - Formation and photoelectron spectroscopy of nanoscale cluster anions of biphenyl, (BP) n - (n = 2-100). AU - Mitsui, Masaaki. AU - Matsumoto, Yukino. AU - Ando, Naoto. AU - Nakajima, Atsushi. PY - 2005/9/5. Y1 - 2005/9/5. N2 - Evolution of electronic structures of nanoscale biphenyl cluster anions, (BP) n - (n = 2-100), have been studied by photoelectron spectroscopy in a size-selective fashion. The energetics of vertical detachment energy (VDE) revealed negative electron affinity of a biphenyl molecule and substantial cluster reorganizations via electron attachment. Comparison of the VDE energetics with naphthalene cluster anions implied that the freezing (and/or melting) temperatures of the BP clusters may be much lower than those of naphthalene clusters.. AB - Evolution of electronic structures of nanoscale biphenyl cluster anions, (BP) n - (n = 2-100), have been studied by photoelectron spectroscopy in a size-selective fashion. The energetics of vertical detachment energy ...
Analysis of thaumasite, Ca₃Si(CO₃)(SO₄)(OH)₆.12(H₂O), by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD ...
Understanding of electrical and electrochemical devices in operating conditions is vital for development of new technologies. Many important characteristics that determine the performance of such devices lie on their surfaces and interfaces which significantly deviate from the bulk properties. However, particularly for the liquid based devices, carrying out surface analysis is challenging and requires highly sophisticated instrumentation. In this PhD. thesis, we aim to unravel the potential development on liquids, dielectrics as well as the liquid/solid interfaces during AC and DC excitation in a chemically resolved fashion using the UHV compatible non-aqueous liquids in a basic electrowetting on dielectrics configuration within X-Ray Photoelectron Spectroscopy (XPS) chamber. Low molecular weight Polyethylene glycol (PEG) and a particular ionic liquid Diethylmethyl(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)imide [DEME][TFSI] are used to represent two extreme cases as being non-ionic ...
Polystyrene thin film surfaces are commonly used to study the interactions of macromolecules, such as proteins, with surfaces. Polystyrene films oxidized in UV light become more hydrophilic, however these surfaces have a limited shelf life because they are reduced over time. Experiments were performed to determine the effect of radiation duration and exposure time on the surface composition of photo-oxidized polystyrene thin films. Polystyrene (2 wt%) in toluene was spin-coated onto 1-cm² monocrystalline silicon squares, and annealed at 70 °C for 18 hours. Three sets of triplicate samples were irradiated in a UV-ozone cleaner for 0, 3, and 9 minutes. Film surface compositions were analyzed via X-ray Photoelectron Spectroscopy 6 hours after irradiation and after one week of air exposure. Overall oxidation level decreased after one week, and the oxidation structure varied with irradiation time. It is speculated that decreases in oxidation level were due to surface contamination and reduction ...
Zinc telluride films doped with gadolinium (ZnTe:Gd)-made by laser ablation and deposition-have been characterized by X-ray photoelectron spectroscopy (XPS) to determine the molecular species of the elements in the material and their presence as intentionally formed contaminants.
This dissertation reports and interprets the results of experiments in which photoelectron spectroscopy was performed on a variety of aromatic anions. In addition to these photoelectron studies, the results and conclusions of an experiment in which HCl is scattered off atomically flat Au (111) surfaces are also presented.. Photoelectron spectroscopy of the isomers of methylphenoxide reveals that these molecules display minimal vibrational excitation upon photodetachment, accessing the electronic ground and first excited state of the corresponding radicals. The photoelectron spectra of p-methylphenoxide reveal a photon energy dependence arising from electron autodetachment. The slow electron velocity map imaging (SEVI) technique was employed to obtain the electron affinities (EAs) of these radicals with an uncertainty of 1.4 meV. Combining the measured EAs with previously measured O-H bond dissociation energies in a thermodynamic cycle allows for the measurement of the acidities of the ...
X-ray Photoelectron Spectroscopy Study Of Adsorption Of (3-mercaptopropyl)trimethoxysilane And N-propyltriethoxysilane On A Rutile TiO2(110) Surface
The frontier electronic structures of Ru(tcterpy)(NCS)3 [black dye (BD)] and Ru(dcbpy)2(NCS)2 (N719) have been investigated by photoelectron spectroscopy (PES), X-ray absorption spectroscopy (XAS) and resonant photoelectron spectroscopy (RPES). N1s XAS has been used to probe the nitrogen contribution in the unoccupied density of states, and PES, together with RPES over the N1s edge, has been used to delineate the character of the occupied density of states. The experimental findings of the frontier electron structure are compared to calculations of the partial density of states for the nitrogens in the different ligands (NCS and terpyridine/bipyridine) and for Ru4d. The result indicates large similarities between the two complexes. Specifically, the valence level spectra show two well separated structures at low binding energy. The experimental results indicate that the outermost structure in the valence region largely has a Ru4d character but with a substantial character also from the NCS ...
You may also wish to search for items by Leopold, D. and Leopold. 26 matching references were found. Leopold, D.G.; Murray, K.K.; Miller, A.E.S.; Lineberger, W.C., Methylene: A study of the X3B1 and the 1A1 states by photoelectron spectroscopy of CH2- and CD2-, J. Chem. Phys., 1985, 83, 4849. [all data] Leopold, D.G.; Lineberger, W.C., A study of the low-lying electronic states of Fe2 and Co2 by negative ion photoelectron spectroscopy, J. Chem. Phys., 1986, 85, 51. [all data] Leopold, D.G.; Miller, A.G.; Lineberger, W.C., Determination of the singlet-triplet splitting and electron affinity of, o-benzyne by negative ion photoelectron spectroscopy, J. Am. Chem. Soc., 1986, 108, 1379. [all data] Leopold, D.G.; Miller, T.M.; Lineberger, W.C., Flowing afterglow negative ion photoelectron spectroscopy of dirhenium: Evidence for multiple bonding in Re2 and Re2-, J. Am. Chem. Soc., 1986, 108, 178. [all data] Murray, K.K.; Miller, T.M.; Leopold, D.G.; Lineberger, W.C., Laser photoelectron spectroscopy of ...
In our lab, we use several glove boxes to prepare membranes by VIPS, in which temperature is controlled, as well as relative humidity (from 20% to 100%). Dry cast process is achieved making use of ovens. Characterization of membrane is mainly performed at the Research and Development Center for Membrane Technology, outside the Engineering Building in which our lab is located. We use scanning electron microscope (SEM) and atomic force microscope (AFM) to characterize the structures. Porosity is assessed by nitrogen adsorption/desorption method. For surface chemical composition, FT-IR and x-ray photoelectron spectroscopy (XPS) tests, as well as X-ray diffraction (XRD) measurements for semi-crystalline and crystalline polymer membranes, are carried out. Mechanical properties of polymer membranes are evaluated performing tensile tests. Water contact angle, hydration capacity, protein adsorption, bacterial attachment and blood compatibility experiments are performed in collaboration with the ...
Ultra thin Al2O3 and HfO2 films (UP to similar to6 nm) were deposited on SiO2/Si wafers by atomic layer chemical vapour deposition (ALCVD(TM,1)) and studied by exsitu X-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry (SE). The thickness of these high-k layers (including the thick... DRIVER (German) ...
You may also wish to search for items by Turner, D. and Turner. 51 matching references were found. Evans, S.; Green, J.C.; Green, M.L.H.; Orchard, A.F.; Turner, D.W., Study of the bonding in pentacarbonylmanganese derivatives by photoelectron spectroscopy, Faraday Discuss. Chem. Soc., 1969, 47, 112. [all data] Al-Joboury, M.I.; Turner, D.W., Molecular photo-electron spectroscopy. Part I. The hydrogen and nitrogen molecules, J. Chem. Soc., 1963, 5141. [all data] Al-Joboury, M.I.; Turner, D.W., Molecular photoelectron spectroscopy. Part II. A summary of ionization potentials, J. Chem. Soc., 1964, 4434. [all data] Turner, D.W.; Al-Joboury, M.I., Molecular photoelectron spectroscopy, Bull. Soc. Chim. Belges, 1964, 73, 428. [all data] Al-Joboury, M.I.; May, D.P.; Turner, D.W., Molecular photoelectron spectroscopy. Part IV. The ionisation potentials and configurations of carbon dioxide, carbon oxysulphide, carbon disulphide, and nitrous oxide, J. Chem. Soc., 1965, 6350. [all data] Al-Joboury, M.I.; ...
Detail záznamu - Threshold Photoelectron Spectroscopy of the Methyl Radical Isotopomers, CH3, CH2D, CHD2 and CD3: Synergy between VUV Synchrotron Radiation Experiments and Explicitly Correlated Coupled Cluster Calculations - Detail záznamu - Knihovna Akademie věd České republiky
AbeBooks.com: Photoelectron Spectroscopy (9780408705592) by J.H.D. Eland and a great selection of similar New, Used and Collectible Books available now at great prices.
Photoemission spectroscopy (PES), also known as photoelectron spectroscopy,[1] refers to energy measurement of electrons emitted from solids, gases or liquids by the photoelectric effect, in order to determine the binding energies of electrons in a substance. The term refers to various techniques, depending on whether the ionization energy is provided by an X-ray photon, an EUV photon, or an ultraviolet photon. Regardless of the incident photon beam however, all photoelectron spectroscopy revolves around the general theme of surface analysis by measuring the ejected electrons.[2] X-ray photoelectron spectroscopy (XPS) was developed by Kai Siegbahn starting in 1957 [3][4] and is used to study the energy levels of atomic core electrons, primarily in solids. Siegbahn referred to the technique as Electron Spectroscopy for Chemical Analysis (ESCA), since the core levels have small chemical shifts depending on the chemical environment of the atom which is ionized, allowing chemical structure to be ...
The use of X-ray photoelectron spectroscopy (XPS) is expanding rapidly with the advent of more convenient, high-resolution laboratory-based instruments. The increase in the numbers and distribution of synchrotrons has also fuelled this burgeoning interest. Powell (C. J. Powell, J. Vac. Sci. Technol. A 21 (S42) 2003) has shown that the number of papers published on or using XPS has doubled in the past 10 years. He reports that there are in excess of 3000 papers published using XPS data each year across a wide range of applications, making it the most important technique for the determination of the composition of nano-scale surface films. Yet XPS and the associated technique of Auger-electron spectroscopy (AES) are not yet developed to the stage where the data and its interpretation are unambiguous. Auger photoelectron coincidence spectroscopy (APECS) provides a means of simplifying spectra, allowing for the decomposition of these into components that have a common origin. The spectra so produced ...
The global XPS market was valued at USD 439.64 million in 2014 and is expected to grow at a CAGR of 6.2% over the forecast period. Increasing global demand for medical research, pure and safe drugs, minimal medication error and technological advancements are some key drivers of the XPS market
The aim of this study was to develop a thermally and operationally stable trypsin through covalent immobilization onto chitosan magnetic nanoparticles (Fe3O4 @CTS). The successful preparation of the Fe3O4 @CTS nanoparticles was verified by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM), which indicated that the prepared Fe3O4 @CTS nanoparticles have superparamagnetic properties, with an average size of approximately 17 nm. Then, trypsin was covalently immobilized onto the Fe3O4 @CTS nanoparticles at a high loading capacity (149.25 mg/g). The FTIR data demonstrated that the trypsin had undergone a conformational change compared with free trypsin, and the Michaelis constant (Km) and the maximum hydrolysis reaction rate (Vmax) showed that the trypsin immobilized on the Fe3O4 @CTS had a lower affinity for BAEE and lower activity compared with free trypsin. However, the immobilized trypsin ...
The oxidation of group three nitride semiconductors is an important aspect in the fabrication of high power transistors with insulated gates. Gallium nitride (GaN) and its alloys (AlGaN) have electrical properties that are ...
Polyfluorenes with pendant alkoxysilyl groups have been used to prepare inorganic-organic composite nanoparticles (diameter = 80-220 nm) in which the conjugated polymer is dispersed within a silica matrix. Preparation of these nanoparticles is achieved by simultaneous nanoprecipitation of the conjugated polymer and hydrolysis/crosslinking of the alkoxysilyl groups under basic conditions. The composition of the nanocomposites is controlled by addition of an alkoxysilane monomer, tetramethylorthosilicate. The hybrid nanoparticles form highly stable dispersions in water and buffer (pH 9.2). The size of the nanoparticles can be tuned by varying the amount of the alkoxysilane monomer added during the nanoprecipitation process. Increasing the relative amount of alkoxysilane monomer also increases the proportion of polyfluorene chains that adopt the higher energy β-phase conformation within the resultant nanoparticles. Nanoparticles with the highest silica content were found to have increased ...
Annenkov, V.V.; Danilovtseva, E.N.; Pal'shin, V.A.; Aseyev, V.O.; Petrov, A.K.; Kozlov, A.S.; Patwardhan, S.V.; Perry, C.C., 2011: Poly(vinyl amine)-silica composite nanoparticles: models of the silicic acid cytoplasmic pool and as a silica precursor for composite materials formation
Page contains details about example of thermochromic material/light absorbing material/double-wall carbon nanotube composite nanoparticles . It has composition images, properties, Characterization methods, synthesis, applications and reference articles : nano.nature.com
Page contains details about example of encapsulated thermochromic material/light absorbing material/double-wall carbon nanotube composite nanoparticles . It has composition images, properties, Characterization methods, synthesis, applications and reference articles : nano.nature.com
In heterogeneous catalysis, characterization of heterogeneous metal interfaces of bimetallic catalysts is a crucial step to elucidate the catalytic performance and is a key to develop advanced catalysts. However, analytical techniques such as X-ray photoelectron spectroscopy can only work in vacuum conditions and are difficult to use for in situ analysis. Here, we present efficient and convenient core-shell nano particle-enhanced Raman spectroscopy to explore the in situ electronic structures of heterogeneous interfaces ([email protected] and [email protected] core-shell NPs) by varying the shell thickness. The experimental observations reported here clearly show that Pd donates electrons to Au, while Pt accepts electrons from Au at the heterogeneous interfaces. This conclusion gains further support from ex situ X-ray photoelectron spectroscopy results. The Au core greatly affects the electronic structures of both the Pd and Pt shells as well as catalytic behaviors. Finally, the as prepared core-shell nanoparticles ...
Photosynthesis, i.e. the conversion of sun light into stored chemical energy by plants and other organisms, is one of the most important global biological processes. In light of increasing energy prices, limited fossil fuel resources and rising environmental concerns, researchers have long dreamed of reproducing this natural process in order to address the challenge of sustainable and eco-friendly energy production. A particularly difficult photosynthetic step to replicate is the oxidation of water and concomitant production of oxygen, which, in artificial systems, require the use of catalysts that are both reactive and stable. In a recent study researchers probed changes in an iridium oxide catalyst during water oxidation, providing crucial insights into the catalytic performance of this material.
The interface formation upon vapor deposition of a metal onto a molecular organic semiconductor was studied using a well-defined complexation reaction between a metal and a porphyrin. Specifically, metallic cobalt (Co) was vapor deposited onto a thin film of 2H-tetraphenylporphyrin (2HTPP) at room temperatur
Modifications were made to the fraction with a particle size less than 150 μm, which was separated from the raw vermiculite through sieving, with no prior purification, and had a cationic exchange capacity of 1.10 meq g-1 (Campos, et al., 2009).. Charge reduction treatment. Natural vermiculite was submitted to hydrothermal treatment, aiming its charge reduction at 400 °C under a partial water vapor pressure of 75% in nitrogen, according to conditions established previously (Cristiano, et al., 2005). This solid was used as a starting material in the synthesis and labeled as H400V75.. With the purpose of achieving more efficiency during the process of inserting the pillaring species within the clay layers, H400V75 was then homoionized with sodium by adding a 3 M sodium chloride solution to a suspension of the solid at 5% p/v under constant magnetic stirring for one hour at 80°C. Finally, the clays were washed with distilled water and dried in air at 60°C.. Modification with Al-Zr, Al-Hf and ...
X-ray photoelectron spectroscopy (XPS) has been used to investigate the evolution of surface chemistry of YBa2Cu3O7-delta (Y123) films prepared by the metalorganic deposition (MOD) process using trifluoroacetate (TFA) precursors. Detailed XPS core-level spectra obtained from the samples quenched from various points during the calcining and firing stages have been reported for the first time and are used to identify surface species. The XPS data show evidence of formation of intermediate phases such as Y-O-F, BaF2, and CuO during the calcining process, which are the decomposition products of yttrium, barium, and copper trifluoroacetates, respectively. The TFA precursors are completely decomposed at the end of calcination. The change of binding energies for Y 3d(5/2), Ba 3d(5/2), and O ls during the firing process indicates that Y123 starts to form at 800 degrees C after 0.5 h firing. Based on the experimental results, an alternative mechanism of the chemical evolution from precursor to final film in the
Compounds forming alloys with lithium, such as silicon or tin, are promising negative electrode materials for the next generation of Li-ion batteries due to their higher theoretical capacity compared to the current commercial electrode materials.. An important issue is to better understand the phenomena occurring at the electrode/electrolyte interfaces of these new materials. The stability of the passivation layer (SEI) is crucial for good battery performance and its nature, formation and evolution have to be investigated. It is important to follow upon cycling alloying/dealloying processes, the evolution of surface oxides with battery cycling and the change in surface chemistry when storing electrodes in the electrolyte.. The aim of this thesis is to improve the knowledge of these surface reactions through a non-destructive depth-resolved PES (Photoelectron spectroscopy) analysis of the surface of new negative electrodes. A unique combination utilizing hard and soft-ray photoelectron ...
Surface chemical compositions of starch nanocrystals (SNC) prepared using sulfuric acid (H2SO4) and hydrochloric acid (HCl) hydrolysis were analyzed by X-ray photoelectron spectroscopy (XPS) and FT-IR. The results showed that carboxyl groups and sulfate esters were presented in SNC after hydrolysis with H2SO4, while no sulfate esters were detected in SNC during HCl-hydrolysis. TEM results showed that, compared to H2SO4-hydrolyzed sample, a wider size distribution of SNC prepared by HCl-hydrolysis were observed. Zeta-potentials were −23.1 and −5.02 mV for H2SO4- and HCl-hydrolyzed SNC suspensions at pH 6.5, respectively. Nevertheless, the zeta-potential values decreased to −32.3 and −10.2 mV as the dispersion pH was adjusted to 10.6. After placed 48 h at pH 10.6, zeta-potential increased to −24.1 mV for H2SO4-hydrolyzed SNC, while no change was detected for HCl-hydrolyzed one. The higher zeta-potential and relative small particle distribution of SNC caused more stable suspensions compared to
... is a collaborative effort of the Helmholtz-Zentrum Berlin, the Humboldt Universität zu Berlin (HU) and the Integrative Research Institute for the Sciences Adlershof (IRIS). The goal of this project is to build and operate a beamline with a suitable end-station for materials science in the field of energy research. The new dipole-PGM (plane grating mirror) beam-line is optimized for the 20 eV to 1.5 keV energy range, which is ideally suited to perform ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) measurements. In addition, an attenuator system will be installed, to allow measurements on radiation sensitive samples (,5 pA/cm² sample current).. ...
Silanization has emerged in recent years as a way to obtain a stronger and more stable attachment of biomolecules to metallic substrates. However, its impact on protein conformation, a key aspect that influences cell response, has hardly been studied. In this work, we analyzed by atomic force microscopy (AFM) the distribution and conformation of type I collagen on plasma-treated surfaces before and after silanization. Subsequently, we investigated the effect of the different collagen conformations on fibroblasts adhesion and fibronectin secretion by immunofluorescence analyses. Two different organosilanes were used on plasma-treated titanium surfaces, either 3-chloropropyl-triethoxy-silane (CPTES) or 3-glycidyloxypropyl-triethoxy-silane (GPTES). The properties and amount of the adsorbed collagen were assessed by contact angle, X-ray photoelectron spectroscopy, optical waveguide lightmode spectroscopy, and AFM. AFM studies revealed different conformations of type I collagen depending on the ...
Microscopy, Electrode, Scanning Tunneling Microscopy, Anions, Hydrogen, Adsorption, Role, Solutions, Absorption, Photoelectron Spectroscopy, Spectroscopy, X-ray, X-ray Photoelectron Spectroscopy, Crystallization, Device, Growth, Paper, Semiconductors, Axis, Molecular Structures
We report the 488 nm photoelectron spectrum of the NbCr$^{-}$ anion. For the $^{2}\Delta$ ground state of neutral NbCr, the short bond length (1.894 \AA) and high bond energy (D$_0$ 3.0263(6) eV) measured by R2PI spectroscopy indicate high order multiple bonding. We find that the NbCr$^{-}$ anion has a $^{1}\Sigma^{+}$ ground state, in which the "extra" electron occupies the (4d)$\delta$ bonding orbital, giving a $1\sigma^{2}1\pi^{4}1\delta^{4}2\sigma^{2}$ valence electron configuration and a formal bond order of 6. Low-lying excited states of NbCr (assigned as two $^{2}\Sigma^{+}$ states) and NbCr$^{-}$ ($^{3}\Delta$) are also observed. The spectra provide the electron affinity of NbCr, energies of the $^{2}\Sigma^{+}$ and the $^{3}\Delta$ excited states, vibrational frequencies for the NbCr and NbCr$^{-}$ ground states and for the $^{2}\Sigma^{+}$ excited states, and (from Franck-Condon analyses) differences among the bond lengths of the observed states. These results are compared with our ...
2000) Line structure in photoelectron and Auger electron of CuOx/Cu and Cu by Auger photoelectron coincidence spectroscopy (APECS). In: 11th International Conference on Quantitative Surface Analysis, 3 - 7 July, Guildford, Surrey, UK. ...
The electroactive polymers most commonly studied during the past decade include polyacetylene, polyaniline, polypyrrole, polythiophene, polyphenylene, poly(phenylene sulfide), poly(phenylene vinylenel and some non-conjugated polymers, such as the polyvinylpyridine and poly(N-vinyl-carbazole). These polymers along with their analogs and derivatives have been selected to illustrate the type and level of information which can be obtained by the X-ray photoelectron spectroscopic (XPS) technique. It is demonstrated that XPS provides an excellent tool for evaluating the three most important physicochemical properties associated with these polymers, viz., the intrinsic structure, the charge transfer interaction, and the stability and degradation behavior. Some future research directions may involve surface modified or functionalized materials, as well as the application of more surface-sensitive techniques, such as secondary ion mass spectroscopy (SIMS) and scanning tunneling microscopy (STM), which ...
The structure of Nb3O and Nb3O+ determined by pulsed field ionizationâ€"zero electron kinetic energy photoelectron spectroscopy and density functional theory. Yang, Dong-Sheng; Zgierski, Marek Z.; Rayner, David M.; Hackett, Peter A.; Martinez, Ana; Salahub, Dennis R.; Roy, Pierre-Nicholas; Carrington, Tucker // Journal of Chemical Physics;10/1/1995, Vol. 103 Issue 13, p5335 The geometrical structures of the ground states of triniobium monoxide, Nb3O, and its cation, Nb3O+, have been determined by an experimental and theoretical study. Vibrationally resolved photoelectron spectra of an Nb3O cluster beam were obtained at 100 and 300 K using the pulsed field... ...
Despite their impressive plasmonic photocatalytic activity, nanosized silver and silver halides always suffer from serious agglomeration and photocorrosion, thus are severely restricted in the practical wastewater restoration applications. The design and realization of plasmonic heterojunction nanostructures is an effective way to solve this stability problem, yet the ideal plasmonic catalyst dispersion and immobilization remains a great challenge. In this work, a highly immobilized [email protected]/g-C3N4 plasmonic photocatalyst was developed through a rational in-situ implanting approach, in which the Ag can be homodispersely distributed and strongly coupled with prefixed Cl sites on g-C3N4 nanosheets (CNNS). The X-ray diffraction (XRD) pattern, X-ray photoelectron spectroscopy (XPS) spectra and element mapping images clearly proved the homodispersely distribution of nanosized [email protected] on the CNNS. The optimal [email protected]/CNNS plasmonic photocatalyst with a narrow band gap of 2.45 eV and large specific ...
The function of microcontact printed protein was investigated using surface plasmon resonance (SPR) imaging, X-ray photoelectron spectroscopy spectroscopy (XPS), and XPS imaging. We chose to analyze a model protein system, the binding of an antibody from solution to a microcontact printed protein antigen immobilized to a gold surface. SPR imaging experiments indicated that the microcontact printed protein antigen was less homogeneous, had increased nonspecific binding, and bound less antibody than substrates to which the protein antigen had been physically adsorbed. SPR images of substrates contacted with a poly(dimethylsiloxane) stamp inked with buffer alone (i.e., no protein) revealed that significant amounts of silicone oligomer were transferred to the surface. The transfer of the silicone oligomer was not homogeneous, and the oligomer nonspecifically bound protein (BSA and IgG) from solution. XPS spectroscopy and imaging were used to quantify the amount of silicon (due to the presence of silicone
A non-aqueous secondary cell having a positive electrode, an electrolytic solution which contains an organic solvent, and a negative electrode which is made of a carbon material having a ratio of I O to I C at least 2, where I O is a peak intensity of oxygen atoms around 530-540 eV and I C is a peak intensity of carbon atoms around 285 eV in a photoelectron spectrum of an X-ray photoelectron spectroscopy under conditions of 12 kV and 10 mA, which cell has a small retention, a large capacity, and safety against ignition.
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cis-Pinic acid is one of the most important oxidation products of α-pinene - a key monoterpene compound in biogenic emission processes. Molecular level understanding of its interaction with water in cluster formation is an important and necessary prerequisite for ascertaining its role in the aerosol
We investigate the evolution of copper phthalocyanine thin films as they are etched with argon plasma. Significant morphological changes occur as a result of the ion bombardment; a planar surface quickly becomes an array of nanopillars which are less than 20 nm in diameter. The changes in morphology are independent of plasma power, which controls the etch rate only. Analysis by X-ray photoelectron spectroscopy shows that surface concentrations of copper and oxygen increase with etch time, while carbon and nitrogen are depleted. Despite these changes in surface stoichiometry, we observe no effect on the work function. The absorbance and X-ray diffraction spectra show no changes other than the peaks diminishing with etch time. These findings have important implications for organic photovoltaic devices which seek nanopillar thin films of metal phthalocyanine materials as an optimal structure.
We present an in situ Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) study of the photo-induced SO2 fixation on anatase TiO2 films. TiO2 films were prepared by DC magnetron sputtering and subsequently exposed to SO2 gas mixed in synthetic air. Simultaneous UV irradiation and SO2 exposure between 373 and 523 K resulted in significant SOx deposits on crystalline TiO2 films as determined by XPS, whereas amorphous films contained negligible amounts of SOx species. The oxidation state of sulfur successively changed from S4+ for SO2 adsorbed on crystalline TiO2 films at room temperature without irradiation to S6+ for films exposed to SO2 at elevated temperatures with simultaneous irradiation. With in situ FTIR the temporal evolution of the photo-induced surface reaction products formed on the TiO2 surfaces was monitored. It is shown that band gap excitation of TiO2 results in photo-induced oxidation of SO2 to form sulfite and sulfate species, which at elevated ...
The Janus amphiphilic particles have gained much attention for their important application value in areas as diverse asinterfacial modification, sensors, drug delivery, optics and actuators. In this work, we prepared Janus amphiphilic nanosheets composed of nitrogen doped stratiform meso-macroporous carbons (NMC) and molybdenum sulfide (MoS2) for hydrophilic and hydrophobic side, respectively. The dicyandiamide and glucose were used as precursors for synthesizing two-dimensional nitrogen doped meso-macroporous carbons and the molybdate could be anchored by the functional groups, on the surface of carbon layers, then transform into uniformly MoS2 to form the Janus amphiphilic layer by layer NMC/MoS2 support. Transmission electron microscope (TEM)ï¼ Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy, are used to demonstrate the successful preparation of Janus materials. As typical interfacial enzyme, Candida Rugosa lipase ...
A common non-ionic surfactant, Triton X-100, was used to modify the chemical bath deposition (CBD) of CdS buffer layers on Cu(In,Ga)Se2 (CIGS) thin films. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) data demonstrate that films produced with the surfactant have about the same levels of impurities as films grown without it. For thin, ~130 ..ANG.. CdS layers and relative to devices made without the surfactant, average absolute cell efficiencies were increased from 10.5% to 14.8%, or by a relative 41%. Visual inspection of the CdS depositions reveals one possible mechanism of the surfactants effects: bubbles that form and adhere to the CIGS surface during the CBD reaction are almost completely eliminated with the addition of the TX-100. Thus, pinholes and thin areas in the CdS layers caused by poor wetting of the substrate surface are sharply reduced, leading to large increases in the open circuit voltage in devices produced with the surfactant.