Ingenieurwissenschaften und zugeordnete Tätigkeiten
Filtern
Erscheinungsjahr
- 2019 (40) (entfernen)
Dokumenttyp
Schlagworte
- Nanoparticles (8)
- Electron microscopy (5)
- Traceability (4)
- Boehmite (3)
- EPMA (3)
- Inter-laboratory comparison (3)
- Nanocomposite (3)
- Particle size distribution (3)
- Reference materials (3)
- Spectroscopic ellipsometry (3)
- XPS (3)
- EU FP7 project NanoValid (2)
- Electron probe microanalysis (EPMA) (2)
- Epoxy (2)
- Iridium-titanium mixed oxides (2)
- Mesoporous thin films (2)
- NEXAFS (2)
- NanoSIMS (2)
- Nanomaterialien (2)
- Silica nanoparticles (2)
- Thin films (2)
- VAMAS (2)
- VSSA (2)
- AEROSIL® OX50 (1)
- AISI 304L (1)
- Advanced Materials (1)
- Advanced materials (1)
- Anatase (1)
- Antifouling surface coatings (1)
- Antiviral activity (1)
- Atomic force microscopy (1)
- Atomic fraction (1)
- Biofilmbildung (1)
- Boehmite nanoparticles (1)
- Bundesoberbehörden (1)
- Cationic photocuring (1)
- Certified reference materials (1)
- Comparability of Measurement Results (1)
- Crosslinking density (1)
- Curing (1)
- Cycloaliphatic epoxy oligosiloxane (1)
- Cycloalyphatic epoxy oligosiloxane (1)
- Definition of nanomaterial (1)
- Deuterium (1)
- Dispersion of nano materials (1)
- EC4SafeNano (1)
- EMPIR (1)
- Electrochemical sensing (1)
- Elemental composition (1)
- Ellipsometric porosimetry (1)
- Ellipsometry (1)
- Epoxy conversion degree (1)
- Fe-Ni (1)
- Femtosecond laser (1)
- Forschungsstrategie (1)
- Functionalized nanographene (1)
- Graphene (1)
- Human umbilical cell adhesion (1)
- Hydrogen (1)
- Hydrothermal synthesis (1)
- IR spectroscopy (1)
- ISO (1)
- Infrared nano AFM (1)
- Inter-laborator comparison (1)
- Intermodulation (1)
- Intermodulation AFM (1)
- Interphase (1)
- Korrosion (1)
- Korrosionsüberwachung (1)
- LEVASIL 50/50 (1)
- Laser-induced periodic surface structures (LIPSS) (1)
- Layer-by-layer deposition (1)
- Linear polyglycerol (1)
- MIC (1)
- Martensite (1)
- Mesoporous iridium-titanium mixed oxides (1)
- Mesoporous mixed metal oxide films (1)
- Microanalysis (1)
- Microbeam analysis (1)
- Mussel-inspired adhesives (1)
- Nano (1)
- Nano particle (1)
- Nano screening (1)
- NanoValid (1)
- Nanocomposites (1)
- Nanomaterial Properties (1)
- Nanomechanical properties (1)
- Nanometrology (1)
- Nanoparticle Characterization (1)
- Nanoparticle size measurement (1)
- Nanoparticular TiO2 (Anatase) (1)
- Nanoscale (1)
- Nanotechnologie (1)
- Neuartige Materialien (1)
- Nitrene[2+1]cycloaddition (1)
- Non-spherical shape (1)
- Oberflächenanalytik (1)
- Oberflächenmesstechnik (1)
- Oxidation (1)
- Oxygen evolution reaction (1)
- P25 (1)
- PC characterisation (1)
- Particle size (1)
- Photocuring (1)
- Photooxidation (1)
- Polyethylene glycol (1)
- Post-modification by L-cysteine (1)
- Pre-standardisation (1)
- Qualitätssicherung (1)
- Real-time infrared spectroscopy (1)
- Reference Nanomaterials (1)
- Regulation (1)
- SEM/EDS/STRATAGem (1)
- SIMS (1)
- Shape-controlled (1)
- Si-Ge (1)
- Size distribution (1)
- Sonochemical synthesis (1)
- Specific Surface Area (BET) (1)
- Stand der Normung (1)
- Standardisation (1)
- Standardization (1)
- Surface Chemical Transformation (1)
- Surface characterization (1)
- Surface charge (1)
- Surface functionalization (1)
- TiO2 (1)
- TiO2 nanoparticle (1)
- Titanium dioxide (1)
- ToF-SIMS (1)
- Tribology (1)
- Two-dimensional hexagonal boron nitride(h-BN) (1)
- UV Weathering (1)
- Uncertainty budget (1)
- Wastewater (1)
- X-ray Photoelectron Spectroscopy (XPS) (1)
- Zeta potential (1)
- shape control (1)
- µ-XRF (1)
Organisationseinheit der BAM
- 6.1 Oberflächen- und Dünnschichtanalyse (40) (entfernen)
Eingeladener Vortrag
- nein (16)
Chemical effects during the formation of femtosecond laser-induced periodic surface structures
(2019)
The processing of laser-induced periodic surface structures (LIPSS, ripples) on metals and semiconductors in ambient air is usually accompanied by superficial oxidation effects – a fact that is widely neglected in the current literature. In this contribution, chemical, structural, and mechanical alterations in the formation of femtosecond LIPSS are characterized by a variety of surface analytical techniques, including energy dispersive X-ray analyses (EDX), X-ray photoelectron spectroscopy (XPS), micro Raman spectroscopy (µ-RS), and depth-profiling Auger electron microscopy (AEM). Alternative routes of electrochemical and thermal oxidation allow to qualify the relevance of superficial oxidation effects on the tribological performance in oil lubricated reciprocating sliding tribological tests (RSTT). It is revealed that the fs-laser processing of near-wavelength sized LIPSS on metals leads to the formation of a few hundreds of nanometers thick graded oxide layers, consisting mainly of amorphous oxides. Regardless of reduced hardness and limited thickness, this nanostructured surface layer efficiently prevents a direct metal-to-metal contact in the RSTT and may also act as an anchor layer for specific wear-reducing additives contained in the used engine oil.
If the particle size decreases, the ratio of surface area to volume increases considerably. This provides benefits for all surface-driven processes that run faster or at lower temperatures than larger particles. However, handling and characterization of the nanopowders are much more difficult. Particularly polydisperse powders with irregular shape, as grinding products, represent a challenge. Granulometry in the submicron and nanoscale often leads to incorrect results without knowledge of particle morphology.
This presentation demonstrates potentials of using the volume-specific surface area (SV or VSSA) in the granulometric characterization of nanopowders, for instance, correlations between the volume-specific surface area and the median particle size are discussed considering the particle morphology and the model of the logarithmic normal distribution.
Moreover, the presentation deals with the optimal dispersion of nanopowders during sample preparation. Indirect ultrasound device with defined cooling was developed to prevent both contamination by sonotrode abrasion and sample changes by heat.
Successful granulometric characterization of nanopowders demands both improved dispersion technology and very often an effective combination of two or more measurement methods.
The 44th Meeting of the Versailles Project on Advanced Materials and Standards (VAMAS) Steering Committee has just taken place at NIST in Boulder (CO, USA). BAM participates with significant contributions in Technical Working Areas on nanoparticle and surface chemistry characterization, but also has positioned itself to new global material challenges and trends in the developement of advanced materials and their characterization, such as thermal properties, self-healing materials, and micro- and nanoplastic.
New reference material candidates for traceable size measurement of nonspherical nanoparticles
(2019)
Size measurement of nanoparticles (NP) becomes a challenging analytical problem when non-spherical shapes must be traceably measured. However, most industrial NPs have irregular shapes and broad size distribution making it often more complex to follow European regulatory to identify a material as a nanomaterial according to which accurate measurement of the smallest dimension and its size Distribution is necessary.
The European research project nPSize - Improved traceability chain of nanoparticle size measurements aims to fill this gap by developing potential non-spherical reference nanoparticles, measurement procedures and physical modelling to improve the traceability chain, comparability and compatibility for NP size measurements between different methods. Therefore, new model NP with well-controlled shape has been synthesized and are supposed to be systematically characterized using the traceable methods scanning/transmission electron microscopy, atomic force microscopy and small angle X-ray scattering.
Following NP candidates are under investigation with respect to their homogeneity and stability: (i) titania nanoplatelets (10-15 nm thickness x 50-100 nm lateral), (ii) titania bipyramides (~60 nm length x 40 nm width), (iii) titania acicular particles (100 nm length x 15-20 nm width; aspect ratio 5.5/6), (iv) gold nanorods (~10 nm width x 30 nm length), and (v) gold nanocubes (~55 nm x 55 nm x 55 nm). In addition, sample preparation procedures as well as measurement analysis procedures with evaluation of appropriate measurands and descriptors for each material class and method are being developed to support standardization. To underpin the traceability of the size measurement of nonspherical NP, physical modelling of the signals in e.g. electron microscopy techniques will be used and in combination, the implementation of machine learning is aimed to facilitate measurement Analysis procedures, especially regarding the accurate thresholding/segmentation of the NPs.
The characteristics of TiO2 coatings can greatly influence their final performance in large-scale applications. In the present study self-assembly of TiO2 nanoparticles (NPs) in multiple layers was selected as a deposition procedure on various substrates. For this, the main prerequisite constitutes the surface modification of both NPs and substrate with e.g. silane coupling agents. A set of functionalized TiO2 NPs has been produced by reaction with either (3- aminopropyl)triethoxysilane (APTES) or (3-aminopropyl)phosphonic acid (APPA) to functionalize the NP surface with free amino-groups. Then, the complementary functionalized NP set can be obtained from an aliquot of the first one, through the conversion of free surface amino-groups to aldehydes by reaction with glutaraldehyde (GA). Several types of TiO2 NPs differing in size, shape and specific surface area have been functionalized. FTIR, TGA, SEM/EDS, XPS, Auger electron spectroscopy (AES) and ToF-SIMS analyses have been carried out to evaluate the degree of functionalization, all the analytical methods employed demonstrating successful functionalization of TiO2 NP surface with APTES or APPA and GA.
New reference material candidates for traceable size measurement of non-spherical nanoparticles
(2019)
New model nanoparticles with well-controlled shape were synthesized within the EMPIR project nPSize - Improved traceability chain of nanoparticle size measurements. Their systematic characterization takes place by the traceable methods scanning/transmission electron microscopy, atomic force microscopy and small angle X-ray scattering. Following reference nanoparticle candidates are under investigation with respect to their homogeneity and stability: titania nanoplatelets (10-15 nm x 50-100 nm), titania bipyramides (~60 nm x 40 nm), titania acicular particles (100 nm x 15-20 nm; aspect ratio 5.5/6), gold nanorods (~10 nm x 30 nm), and gold nanocubes (~55 nm x 55 nm x 55 nm).
Challenges in Traceable Size Measurement of Non-Spherical, Non-Monodisperse Nanoparticles - nPSize
(2019)
Size measurement of nanoparticles (NP) becomes a challenging analytical problem when non-spherical shapes must be traceably measured. However, most industrial NPs have irregular shapes and broad size distribution making it often more complex to follow European regulatory to identify a material as a nanomaterial according to which accurate measurement of the smallest dimension and its size Distribution is necessary.
The European research project nPSize - Improved traceability chain of nanoparticle size measurements aims to fill this gap by developing potential non-spherical reference nanoparticles, measurement procedures and physical modelling to improve the traceability chain, comparability and compatibility for NP size measurements between different methods. Therefore, new model NP with well-controlled shape has been synthesized and are supposed to be systematically characterized using the traceable methods scanning/transmission electron microscopy, atomic force microscopy and small angle X-ray scattering.
Following NP candidates are under investigation with respect to their homogeneity and stability: (i) titania nanoplatelets (10-15 nm thickness x 50-100 nm lateral), (ii) titania bipyramides (~60 nm length x 40 nm width), (iii) titania acicular particles (100 nm length x 15-20 nm width; aspect ratio 5.5/6), (iv) gold nanorods (~10 nm width x 30 nm length), and (v) gold nanocubes (~55 nm x 55 nm x 55 nm). In addition, sample preparation procedures as well as measurement analysis procedures with evaluation of appropriate measurands and descriptors for each material class and method are being developed to support standardization. To underpin the traceability of the size measurement of nonspherical NP, physical modelling of the signals in e.g. electron microscopy techniques will be used and in combination, the implementation of machine learning is aimed to facilitate measurement Analysis procedures, especially regarding the accurate thresholding/segmentation of the NPs.zeige mehr
Biofouling constitutes a major challenge in the application of biosensors and biomedical implants, as well as for (food) packaging and marine equipment. In this work, an antifouling surface coating based on the combination of mussel-inspired dendritic polyglycerol (MI-dPG) and an amine-functionalized block copolymer of linear polyglycerol (lPG−b−OA11, OA = oligo-amine) was developed. The coating was compared to a MI-dPG surface which was postfunctionalized with commercially available amine-terminated Polyethylene glycol (HO−PEG−NH2) of similar molecular weight. In the current work, These coatings were compared in their chemical stability, protein fouling characteristics, and cell fouling characteristics. The lPG−b−OA11-functionalized coating showed high chemical stability in both phosphate buffered saline (PBS) and sodium dodecyl sulfate (SDS) solutions and reduced the adhesion of fibrinogen from human plasma with 99% and the adhesion of human serum albumin with 96%, in comparison to the bare titanium dioxide substrate. Furthermore, the Proliferation of human umbilical vein endothelial cells (HUVECs) was reduced with 85% when the lPG−b−OA11 system was compared to bare titanium dioxide. Additionally, a reduction of 94% was observed when the lPG−b−OA11 system was compared to tissue culture polystyrene.
Analysis of elemental composition of Fe1-xNix and Si1-xGex alloy thin films by EPMA and µ-XRF
(2019)
The present study reports on measurements on thin Fe-Ni films on silicon and first-time results of analysis on Si-Ge thin films deposited on a non-conductive aluminium oxide Substrate by electron probe microanalysis (EPMA). Standard-based and standardless EPMA (with EDS) results were used in combination with the thin film analysis software Stratagem for the quantification.
Further, X-ray fluorescence analysis (XRF) can be used for the determination of elemental composition and thickness of such films as well. In this case, XRF with a μ-focus X-ray source (μ-XRF) attached to a SEM was applied. For quantification, a fundamental parameter (FP) approach has been used to calculate standard-based and standardless results.
Both thin film systems have been chosen as samples of an international round robin test (RRT) organised in the frame of standardisation technical committee ISO/TC 201 ‘Surface chemical analysis’, under the lead of KRISS. The main objective of the RRT is to compare the results of atomic fractions of Fe1-xNix and Si1-xGex alloy films obtained by different surface Analysis techniques, such as X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and secondary ion mass spectrometry (SIMS) applied in the depth-profiling operation mode.
Five samples of different atomic fractions of each thin film system, i.e., Fe1-xNix and Si1-xGex, have been grown by ion beam sputter deposition on silicon and Al2O3 wafers, respectively. Reference FeNi and SiGe films with well-known elemental composition and thickness have been also supplied for standard-based analysis. An excellent agreement has been obtained between the atomic fractions determined by EPMA and µ-XRF with the KRISS certified values.