Analytische Chemie
Filtern
Erscheinungsjahr
Dokumenttyp
- Zeitschriftenartikel (81)
- Vortrag (17)
- Sonstiges (7)
- Beitrag zu einem Sammelband (5)
- Posterpräsentation (4)
- Corrigendum (1)
- Forschungsbericht (1)
Schlagworte
- XPS (45)
- NEXAFS (21)
- Graphene (9)
- SIMS (9)
- ToF-SIMS (9)
- Metrology (8)
- Nanoparticles (7)
- Surface chemical analysis (7)
- AES (5)
- Lateral resolution (5)
- Data fusion (4)
- NAP-XPS (4)
- Reference material (4)
- SEM (4)
- X-ray photoelectron spectroscopy (4)
- Bacteria (3)
- Biofilms (3)
- Core-shell (3)
- Core-shell nanoparticles (3)
- Depth profiling (3)
- EBSD (3)
- EDX (3)
- Graphene oxide (3)
- Nanotechnology (3)
- Standardization (3)
- Surface analysis (3)
- X-ray Photoelectron Spectroscopy (XPS) (3)
- 3D nano SIMS (2)
- AFM (2)
- ATR-FTIR spectroscopy (2)
- CCQM (2)
- CIGS (2)
- Click chemistry (2)
- Duplex stainless steel (2)
- E. coli (2)
- Fe L3 edge absorption spectra (2)
- Hydrogen assisted cracking (2)
- Hydrogen embrittlement (2)
- Imaging (2)
- Imaging XPS (2)
- Ionic liquids (2)
- Mapping (2)
- Method development (2)
- Nanomaterials (2)
- Plasma (2)
- Polymers (2)
- Quantum dot (2)
- Raman-spectroscopy (2)
- Reproducibility (2)
- STXM (2)
- Small-spot XPS (2)
- Standards (2)
- Thickness (2)
- Time-of-flight secondary ion mass spectrometry (2)
- VAMAS (2)
- X-ray spectroscopy (2)
- 'Click' reaction (1)
- (Quantitative) Structure-Active Relationships (1)
- (ter-)pyridineterminated self-assembled monolayer (1)
- 2D (1)
- 4,4'-dimercaptoazobenzene (1)
- Amides (1)
- Amines (1)
- Analysis area measurements (1)
- Analysis of liquids (1)
- Analytical methods (1)
- Antibacterial surface coatings (1)
- Antifouling surface coatings (1)
- Antiviral activity (1)
- Aqueous Solutions (1)
- Aqueous media (1)
- Ar gas cluster gun (1)
- Argon gas cluster ion sputtering (1)
- Auger Electron Spectroscopy (1)
- Auger Electron Spectroscopy (AES) (1)
- Auger-electron spectroscopy (AES) (1)
- Azidation (1)
- Azide-terminated surfaces (1)
- BAM L200 (1)
- BET specific surface area (1)
- Bacteria detection (1)
- Bifunctional 2D nanomaterials (1)
- Bio sensing device (1)
- Biochip (1)
- Biofilm (1)
- Biointerfaces (1)
- Bioorganic film (1)
- Biosensors (1)
- Bismuth titanates (1)
- Boronic acid (1)
- Boronic acid-functionalized 2D MoS2 (1)
- CCQM (Consultative Committee for Amount of Substance) (1)
- CEN (1)
- CIGS thin films (1)
- CRM (1)
- Cancer (1)
- Carbon nanoparticles (1)
- Catalysis (1)
- Cell sheet fabrication (1)
- Certified reference material (1)
- Characterisation (1)
- Characterization and analytical techniques (1)
- Charge (1)
- Chemical derivatization (1)
- Chemistry (1)
- Coating (1)
- Comparability (1)
- Comparisons (1)
- Composition (1)
- Concanavalin A (1)
- Concentration (1)
- Core shell nano particle (1)
- Core-shell structures (1)
- Corrosion (1)
- Covalent interactions (1)
- Cryo XPS (1)
- Crystallinity (1)
- DFT spectrum simulations (1)
- DSM 5009 (1)
- DSS steel (1)
- Data correlation (1)
- Density functional theory (1)
- Depth Profiles and Images (1)
- Diffusion/diffusivity (1)
- Dispersion of nanomaterials (1)
- EDS (1)
- EPMA (1)
- Electrochemical sensing (1)
- Electron backscatter diffraction (1)
- Electron effective attenuation length (1)
- Electron spectroscopy (1)
- Eluting stent (1)
- Escherichia coli (1)
- Euramet EMRP (1)
- European Centre (1)
- FIB (1)
- Ferrocene (1)
- Ferroelectricity/ferroelectric materials (1)
- Field of view (1)
- Fluorescence (1)
- Fourier transform infrared spectroscopy (1)
- Fourier-Transform Infrared Spectroscopy (1)
- Fullerene (1)
- Fullerene-Polyglycerol Sulfates (1)
- Functionalization of fullerenes (1)
- Functionalized graphene (1)
- Functionalized nanographene (1)
- Glycan microarray (1)
- Graphen Oxide (1)
- Graphene–bacteria interaction (1)
- Grating method (1)
- Guest complexe (1)
- H-terminated Si3N4 films (1)
- HKUST-1 (1)
- HR-SEM (1)
- Hazard assessment (1)
- Host guest molecules (1)
- Human umbilical cell adhesion (1)
- Hydrogen (1)
- Hydrogen trapping (1)
- Hydrogen-assisted cracking (1)
- Hydrogenated nanostructures (1)
- IR (1)
- IR spectroscopy (1)
- ISO (1)
- ISO 23173 (1)
- ISO standards (1)
- Imaging AES (1)
- Imaging SIMS (1)
- Imaging ToF SIMS (1)
- Imaging surface chemical analysis (1)
- Imaging technique (1)
- Inelastic background (1)
- Infectious diseases (1)
- Inter-laboratory comparisons (1)
- Interaction with atmospheres (1)
- International Meter Convention (1)
- Iodine (1)
- Ionic liquid (1)
- Iron oxide (1)
- Isothermal nucleic acid amplification (1)
- Key comparison (1)
- Lead-free ceramics (1)
- Lean duplex stainless steel (1)
- Line scan (1)
- Linear polyglycerol (1)
- Liposomes (1)
- Low energy (1)
- Macrocycles (1)
- Magnetic iron oxide nanoparticle clusters (1)
- Magnetic nanoparticles (1)
- Martin Seah (1)
- Mass spectrometry (1)
- Metal fluorides (1)
- Metal ions (1)
- Metal-organic frameworks (1)
- Metrology in Chemistry and Biology (1)
- Microscopy (1)
- Molecular recognition at interfaces (1)
- Monolayer (1)
- Multilayers (1)
- Mussel-inspired adhesives (1)
- Mussel-inspired dendritic polyglycerol (MI-dPG) (1)
- NAT (1)
- Nano (1)
- Nano materials (1)
- Nano-safety (1)
- Nanoanalytik (1)
- Nanobiointerfaces (1)
- Nanoinformatics (1)
- Nanoparticle characterization (1)
- Nanopartikel (1)
- Nanoplatform (1)
- Nanoporous Al2O3 (1)
- Nanosicherheit (1)
- Nanotechnologie (1)
- Nano‐object characterization (1)
- Narrow line method (1)
- Near Ambient Pressure XPS (1)
- Near ambient pressure XPS (1)
- Near edge X-ray absorption fine structure (1)
- Near-ambient pressure X-ray photoelectron spectroscopy (1)
- Nitrene [2+1] cycloaddition (1)
- Nitrene[2+1]cycloaddition (1)
- Nm film thickness (1)
- NoStep Standards (1)
- Noise in image (1)
- Nucleic acid tests (1)
- Organic layers (1)
- P. Fluorescens (1)
- PCR (1)
- PS (1)
- PTFE (1)
- Particle architecture (1)
- Pd 3d (1)
- Peptides (1)
- Photoluminescence (1)
- Photophysics (1)
- Photoswitchable monolayers (1)
- Photoswitchable rotaxane (1)
- Physicochemical characterization (1)
- Plasma deposition (1)
- Plasma-nitrogenated polyolefin surfaces (1)
- Plasmapolymer (1)
- Plasmonic catalysis (1)
- Polyethylene glycol (1)
- Polyethylene glycol (PEG)-grafting antifouling surface (1)
- Pore diameter (1)
- Post-modification by L-cysteine (1)
- Predictive modelling (1)
- Principal component analysis (PCA) (1)
- Proteins (1)
- Protocol development (1)
- Provenance information (1)
- Pseudorotaxanes (1)
- Pyridine (1)
- QUASES (1)
- Quantitative XPS (1)
- Quantitative surface chemical analysis (1)
- Quantum yield (1)
- Questionnaire (1)
- Reference-free XRF (1)
- Reproducible Spectra (1)
- Resolution criterion (1)
- Risk management (1)
- Ru dye sensitizer (1)
- SAMs (1)
- SAXS (1)
- Safe innovation (1)
- Safe-by-design (1)
- Sample preparation (1)
- Scanning transmission x- ray microscopy (1)
- Scanning transmission x-ray microscopy (STXM) (1)
- Selected area XPS (1)
- Self assembly (1)
- Self-degrading (1)
- Semiconductor (1)
- Shape (1)
- Shell (1)
- Silanes (1)
- Silicon nitride (1)
- Silver nanoparticles (1)
- Single particle (1)
- Size distribution (1)
- Small-area XPS (1)
- Sol-gel synthesis (1)
- Specific adsorption (1)
- Specific pore volume (1)
- Spectrum simulation (1)
- Standard operation procedures (1)
- Standardisation (1)
- Status report (1)
- Straight edge method (1)
- Streptavidin binding (1)
- Supramolecular Chemistry (1)
- Surface Analysis (1)
- Surface Analysis Working Group (1)
- Surface charge (1)
- Surface chemical analysis of biofilms (1)
- Surface functionalization (1)
- Surface-enhanced Raman scattering (1)
- Suspensions (1)
- Synchrotron radiation (1)
- Synchrotron radiation XPS (1)
- Synthesis (1)
- T-SEM (1)
- TEM (1)
- TGA (1)
- Test pattern (1)
- Thermal annealing (1)
- Thermal desorption spectrometry (TDS) (1)
- Thermoresponsive poly(glycidyl ether) coatings (1)
- Thumor therapy (1)
- TiO2 films (1)
- ToF SIMS (1)
- Transmission function (1)
- Trends (1)
- Triazine (1)
- Two-dimensional hexagonal boron nitride(h-BN) (1)
- UV/Vis (1)
- Unsaturated CN bonds (1)
- Variable excitation (1)
- Virus detection (1)
- Water (1)
- Well-ordered macrocycle multilayers (1)
- Wet cell (1)
- X-ray fluorescence (XRF) (1)
- X-ray spectromicroscopy (1)
- X-rays (1)
- XAS (1)
- XRF (1)
- absorption spectroscopy (1)
- analytical service (1)
- dyes (1)
- fluorescence spectroscopy (1)
- p-aminothiophenol (1)
- silica nanoparticles (1)
- surface and in-depth inspection (1)
- surface group quantification (1)
- titania nanoparticles (1)
- ß-amino-cyclodextrin (1)
Organisationseinheit der BAM
- 6 Materialchemie (57)
- 6.1 Oberflächen- und Dünnschichtanalyse (57)
- 4 Material und Umwelt (5)
- 4.1 Biologische Materialschädigung und Referenzorganismen (5)
- 1 Analytische Chemie; Referenzmaterialien (1)
- 1.2 Biophotonik (1)
- 6.2 Material- und Oberflächentechnologien (1)
- 9 Komponentensicherheit (1)
- 9.0 Abteilungsleitung und andere (1)
Eingeladener Vortrag
- nein (17)
Mechanically interlocked molecules (MIMs) such as rotaxanes and catenanes are capable of mechanical motion on the nanoscale and are therefore promising prototypes for molecular machines in recent nanotechnology. However, most of the existing examples are isotropically distributed in solution, which prohibits concerted movement and with it the generation of macroscopic effects. Thus, arranging them in ordered arrays is of huge interest in recent research. We report the deposition of quite densely packed multilayers of tetralactam macrocycles on gold surfaces by metal-coordinated layer-by-layer self-assembly. Linear dichroism effects in angle-resolved NEXAFS spectra indicate a preferential orientation of the macrocycles. The sequence of the metal ions can be programmed by the use of different transition metal ions at each deposition step. Additionally, reversible on-surface pseudorotaxane formation was successfully realized by repeated uptake and release of axle molecules inside the macrocycles cavities.
This survey will discuss current and emerging isothermal and rapid polymerase chain reaction (PCR) based nucleic acid amplification methods for patient near diagnostics. To assess the clinical need of rapid diagnostics for infectious diseases based on nucleic acid tests (NATs) we performed and analysed a questionnaire among laboratories participating in corresponding INSTAND ring trials for external quality assurance. The questions concerning new amplification technologies like isothermal nucleic acid amplification, potentially suited to significantly decrease turnaround times, were complemented by questions to evaluate the present status of NATs. Besides end-users, companies were also addressed by sending out a manufacturer specific questionnaire. Analysis of the answers from 48 laboratories in 14 European countries revealed that a much shorter turnaround time is requested for selected pathogens compared to about 2 h or longer when applying temperature cycling amplification, i.e. PCR. In this context, most frequently mentioned were MRSA, norovirus, influenza A and B viruses, cytomegalovirus (CMV) as well as hepatitis B virus (HBV) and hepatitis C virus (HCV). At present, 8% of the laboratories having participated in this survey apply isothermal amplification of nucleic acid to identify infectious pathogens.
Recently, C K-edge Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra of graphite (HOPG) surfaces have been measured for the pristine material, and for HOPG treated with either bromine or krypton plasmas (Lippitz et al., Surf. Sci., 2013, 611, L1). Changes of the NEXAFS spectra characteristic for physical (krypton) and/or chemical/physical modifications of the surface (bromine) upon plasma treatment were observed. Their molecular origin, however, remained elusive. In this work we study by density functional theory, the effects of selected point and line defects as well as chemical modifications on NEXAFS carbon K-edge spectra of single graphene layers. For Br-treated surfaces, also Br 3d X-ray Photoelectron Spectra (XPS) are simulated by a cluster approach, to identify possible chemical modifications. We observe that some of the defects related to plasma treatment lead to characteristic changes of NEXAFS spectra, similar to those in experiment. Theory provides possible microscopic origins for these changes.
In order to investigate molecular recognition on surfaces, an azide-functionalized monolayer was deposited on gold. The monolayer was characterized by X-ray photoelectron spectroscopy (XPS) and angle-resolved near-edge X-ray absorption fine structure (NEXAFS) experiments and the decomposition of the azide upon irradiation with X-ray beams was investigated. Subsequently, various alkyne-functionalized host and guest molecules were attached to the azide by 1,3-dipolar cycloaddition. These modified surfaces and their host–guest chemistry were analysed by XPS and angle-resolved NEXAFS. The reversibility of guest binding was shown for one example as a proof of principle.
The combination of complementary characterization techniques such as SEM (Scanning Electron Microscopy), T-SEM (Scanning Electron Microscopy in Transmission Mode), EDX (Energy Dispersive X-ray Spectroscopy) and SAM (Scanning Auger Microscopy) has been proven to be a powerful and relatively quick characterization strategy for comprehensive morphological and chemical characterization of individual silica and titania nanoparticles. The selected real life test materials, silica and titania, are listed in the OECD guidance manual as representative examples because they are often used as commercial nanomaterials. Imaging by high resolution SEM and in the transmission mode by T-SEM allows almost simultaneous surface and in-depth inspection of the same particle using the same instrument. EDX and SAM enable the chemical characterization of bulk and surface of individual nanoparticles. The core–shell properties of silica based materials are addressed as well. Titania nominally coated by silane purchased from an industrial source has been found to be inhomogeneous in terms of chemical composition.
Solgel prepared ternary FeF3–MgF2 materials have become promising heterogeneous catalysts due to their porosity and surface Lewis/Brønsted acidity (bi-acidity). Despite the good catalytic performance, nanoscopic characterisations of this type of material are still missing and the key factors controlling the surface properties have not yet been identified, impeding both a better understanding and further development of ternary fluoride catalysts. In this study, we characterised the interaction between the bi-acidic component (FeF3) and the matrix (MgF2) on the nano-scale. For the first time, the formation pathway of FeF3–MgF2 was profiled and the template effect of MgF2 during the synthesis process was discovered. Based on these new insights two novel materials, FeF3–CaF2 and FeF3–SrF2, were established, revealing that with decreasing the atomic numbers (from Sr to Mg), the ternary fluorides exhibited increasing surface acidity and surface area but decreasing pore size. These systematic changes gave rise to a panel of catalysts with tuneable surface and bulk properties either by changing the matrix alkaline earth metal fluoride or by adjusting their ratios to Fe or both. The template effect of the alkaline earth metal fluoride matrix was identified as the most probable key factor determining the surface properties and further influencing the catalytic performance in ternary fluoride based catalysts, and paves the way to targeted design of next-generation catalysts with tunable properties.
In Near Edge X-Ray Absorption Fine Structure (NEXAFS) spectroscopy X-Ray photons are used to excite tightly bound core electrons to low-lying unoccupied orbitals of the system. This technique offers insight into the electronic structure of the system as well as useful structural information. In this work, we apply NEXAFS to two kinds of imidazolium based ionic liquids ([CnC₁im]⁺[NTf₂]⁻ and [C₄C₁im]⁺[I]⁻). A combination of measurements and quantum chemical calculations of C K and N K NEXAFS resonances is presented. The simulations, based on the transition potential density functional theory method (TP-DFT), reproduce all characteristic features observed by the experiment. Furthermore, a detailed assignment of resonance features to excitation centers (carbon or nitrogen atoms) leads to a consistent interpretation of the spectra.
A comprehensive characterization of plasma modified polymer surfaces or plasma-polymerized thin films needs access to parameters as
- concentration of saturated/unsaturated carbon species (e.g. aromaticity) or other double bonds as C=N or C=O,
- branching, and
- losses of crystallinty or other degrees of structural order.
Furthermore the complex ageing phenomena of plasma modified polymers/plasma-polymers and the measurement of an in-depth distribution of chemical species are challenges for the analyst. The talk will display selected examples where such challenges have been met by using advanced methods of surface chemical analyses as Photoelectron Spectroscopy with variable excitation energy (“SyncXPS”), X-ray Absorption Spectroscopy (NEXAFS) at C, N and O K-edges and Time-of-Flight Secondary Mass Spectroscopy (ToF-SIMS) combined with Principal Component analysis (PCA).
In the present work, the influence of deuterium on the microstructure of a duplex stainless steel type EN 1.4462 has been characterized by Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) supported by scanning electron microscopy (SEM), focused ion beam (FIB), electron back scattered diffraction(EBSD) and energy dispersive x-ray (EDX) investigations. Characterization has been carried out before and after electrochemical charging with deuterium which has been used as a tracer, due to its similar behavior to hydrogen in the steel microstructure. In a first approach, the distribution of the deuterium occurring at temperatures above 58 °C has been visualized. Further it turned out that sub-surface micro blisters are formed in the ferrite-austenite interface, followed by the formation of needle shaped plates and subsequent cracking at the ferrite surface. In the austenite phase, parallel cracking alongside twins and hexagonal close packed (martensitic) regions has been observed. In both phases and even in the apparent interface, cracking has been associated with high deuterium concentrations, as compared to the surrounding undamaged microstructure. Sub-surface blistering in the ferrite has to be attributed to the accumulation and recombination of deuterium at the ferrite-austenite interface underneath the respective ferrite grains and after fast diffusing through this phase. Generally, the present application of chemometric imaging and structural analyses allows characterization of hydrogen assisted degradation at a sub-micron lateral resolution.
The growing interest in artificial bioorganic Interfaces as a platform for applications in emerging Areas as personalized medicine, clinical diagnostics, biosensing, biofilms, prevention of biofouling, and other fields of bioengineering is the origin of a need for in Detail multitechnique characterizations of such layers and interfaces. The in-depth analysis of biointerfaces is of special interest as the properties of functional bioorganic coatings can be dramatically affected by in-depth variations of composition.
In worst cases, the functionality of a device produced using such coatings can be substantially reduced or even fully lost.