6 Materialchemie
Filtern
Dokumenttyp
- Zeitschriftenartikel (95) (entfernen)
Schlagworte
- SAXS (53)
- Small-angle X-ray scattering (23)
- Nanoparticle (13)
- X-ray scattering (12)
- Nanoparticles (11)
- MOUSE (8)
- Scattering (7)
- Nanomaterials (4)
- Nanoplastics (4)
- Polymer (4)
- Silver nanoparticles (4)
- Small-angle scattering (4)
- Catalysis (3)
- DNA (3)
- Diffraction (3)
- Ectoine (3)
- Nanocomposite (3)
- Nanostructure (3)
- Radiation damage (3)
- Simulation (3)
- Toxicology (3)
- nanoparticle (3)
- Additive manufacturing (2)
- Amyloid (2)
- Artificial digestion (2)
- Bio-SAXS (2)
- BioSAXS (2)
- Calcium sulfate (2)
- Cosolute (2)
- Data analysis (2)
- Digestion (2)
- Dosimetry (2)
- Dynamic Light Scattering (2)
- Ectoin (2)
- Electrical conductivity (2)
- G5P (2)
- GVP (2)
- Geant4 (2)
- Geant4-DNA (2)
- Gold (2)
- Graphitization (2)
- Instrumentation (2)
- Ionic Liquid Crystals (2)
- Ionizing radiation damage (2)
- LEE (2)
- McSAS3 (2)
- Mesoporous Silica (2)
- Methodology (2)
- Microdosimetry (2)
- Microplastics (2)
- Microwave synthesis (2)
- Molecular mobility (2)
- Monte-Carlo simulations (2)
- Nanopatricle (2)
- OH Radical (2)
- OH radical scavenger (2)
- Polymers (2)
- Protein (2)
- Protein unfolding (2)
- Radical Scavenger (2)
- Reference Material (2)
- Rigid amorphous fraction (2)
- Single-stranded DNA-binding proteins (2)
- Small angle scattering (2)
- Small-angle x-ray scattering (2)
- Small-angle xray scattering (2)
- Struvite (2)
- Synthesis (2)
- Topas-MC (2)
- Topas-nBio (2)
- XAS (2)
- XRD (2)
- Zinc oxide (2)
- ssDNA (2)
- 266nm (1)
- 2PP (1)
- 3D Fourier Transform (1)
- 3D printing (1)
- 3D-printing (1)
- AFM (1)
- ATZ (1)
- Aantimicrobial (1)
- Abasic site (1)
- Advanced calorimetry (1)
- Ag (1)
- Agarose gel electrophorese (1)
- Aging (1)
- Air fragmentation (1)
- Alumina toughened zirconia (1)
- Analytical methods (1)
- Anhydrite (1)
- Antibacterial properties (1)
- Au (1)
- Automated synthesis (1)
- Batteries (1)
- Bioresorbable Biomaterials (1)
- Boson peak (1)
- Broadband Dielectric Spectrscopy (1)
- Broadband dielectric spectroscopy (1)
- CCMat (1)
- COK-12 (1)
- CPD (1)
- Cancer (1)
- Carbon dioxide reduction (1)
- Carbon storage (1)
- Catalyst (1)
- Catalyst layer (1)
- Cathode material (1)
- CdS (1)
- Cellulose nanofibrils (1)
- Ceramic nano particles (1)
- Ceramics and Composites (1)
- Ceria (1)
- Chemically Complex Materials (1)
- Chemputer (1)
- Coaggregation (1)
- Combined techniques (1)
- Compatible solute (1)
- Complex Molecular Systems (1)
- Conference (1)
- Coprecipitation (1)
- Core-clusters (1)
- Counterions (1)
- Covalent Organic Frameworks (1)
- DLS (1)
- DNA base damage (1)
- DNA damage (1)
- DNA melting temperature (1)
- DNA protection (1)
- DNA strand-break (1)
- DTAB (1)
- Data curation (1)
- Data fitting (1)
- Debye scattering equation (1)
- Degradation of polyethylene (1)
- Degradation studies (1)
- Deuterium (1)
- Dielectric spectroscopy (1)
- Differential scanning calorimetry (1)
- Discotic Liquid Crystals (1)
- Dye (1)
- Ectoine DNA protection (1)
- Ectoine UV absorption (1)
- Ectoine-DNA binding (1)
- Electrocatalysis (1)
- Electron density map (1)
- Electronic, Optical and Magnetic Materials (1)
- Electrospinning (1)
- Epoxy nanocomposites (1)
- Estrogenic activity of plastic nanoparticles (1)
- Ex-situ (1)
- Excited states (1)
- FAIR (1)
- FFT (1)
- Fast scanning calorimetry (1)
- Fatigue (1)
- Flash DSC (1)
- Fluorescence (1)
- Food (1)
- Food Science (1)
- Force microscopy (1)
- Fully aromatic frameworks (1)
- Gas separation (1)
- Gas separation membranes (1)
- Gas sorption (1)
- Gastrointestinal barrier (1)
- Gel (1)
- General Chemistry (1)
- General Materials Science (1)
- General Medicine (1)
- Geology (1)
- Graphene Oxide (1)
- Gypsum (1)
- Halloysite nanotubes (1)
- Hierarchically porous (1)
- High resolution (1)
- High specific surface area (1)
- Hydroxyectoine (1)
- Hydroxyl radicals (1)
- In-situ (1)
- In-situ SAXS/WAXS (1)
- Industrial and Manufacturing Engineering (1)
- Interlaboratory comparability (1)
- Ionic liquid (1)
- Iron carbide (1)
- Iron nanoparticles (1)
- Iron nanophases (1)
- Iron nitride (1)
- Large-pore (1)
- Li-ion battery (1)
- Magnetic hyperthermia (1)
- Magnetic nanoparticles (1)
- Materials Chemistry (1)
- Membrane polymers (1)
- Mesocellular foam (1)
- Mesocrystal (1)
- Mesoporosity (1)
- Mesoporous phosphate-based glasses (1)
- Mesoporous silica (1)
- Metal carbides (1)
- Metal organic framework (1)
- Metal-organic polyhedra (1)
- Metals and Alloys (1)
- Methane Oxidation (1)
- Micelle (1)
- Microemulsion (1)
- Microplastic (1)
- Microplastics reference material (1)
- Microporous polymers (1)
- Microstructure (1)
- Multi-core particles (1)
- Multi-principal element alloys (1)
- Naica (1)
- Nano structure (1)
- Nano-ceramic-additive-manufacturing photoresin (1)
- NanoCAM (1)
- Nanocasting (1)
- Nanocomposite fibers (1)
- Nanoconfinement (1)
- Nanometrology (1)
- Nanoporous (1)
- Nanostructure quantification (1)
- Neutron scattering (1)
- Nitrogen (1)
- Non-spherical nanoparticles (1)
- Nucleation (1)
- Numerical models (1)
- OH scavenger (1)
- OMS (1)
- Oral uptake (1)
- Ordered mesoporous silica (1)
- Organic phosphates (1)
- PBS (1)
- PDF (1)
- Particle scatterin simulations (1)
- Particle scattering simulations (1)
- Particle size (1)
- Peptide (1)
- Phosphinine (1)
- Photocatalysis (1)
- Physical aging (1)
- Polymer electrolyte fuel cell (1)
- Polymer of intrinsic microporosity (1)
- Polymers of intrinsic microporosity (1)
- Polynorbornenes (1)
- Pore size tailoring (1)
- Porous carbon (1)
- Porous carbons (1)
- Porous materials (1)
- Pphosphates (1)
- Preferential exclusion (1)
- Pulsed laser ablation (1)
- Purification (1)
- Quantum Dots (1)
- Quantum dots (1)
- Radiation protection (1)
- Radical scavenger (1)
- Raman spectroscopy (1)
- Reference Method (1)
- Reference materials (1)
- Regularization (1)
- Representative morphology modeling (1)
- Risk assessment (1)
- Robocasting (1)
- Round Robin (1)
- SANS (1)
- SSB (1)
- SYBR gold (1)
- Salt (1)
- SchwarzP cells (1)
- Self-assembly (1)
- Silica (1)
- Silicone elastomer (1)
- Sillver (1)
- Slurry (1)
- Small-angle X-ray Scattering (1)
- Sol-gel (1)
- Spectroscopy (1)
- Spinel (1)
- Standardisation (1)
- Structural control (1)
- Structural sealant glazing (1)
- Structure factors (1)
- Sunscreen (1)
- Supramolecules (1)
- Surfaces, Coatings and Films (1)
- Suzuki-Miyaura coupling (1)
- Synchrotron (1)
- The MOUSE (1)
- Therapy (1)
- Ti-based colloids (1)
- Topas (1)
- TopasMC (1)
- Total scattering (1)
- Traceability (1)
- Transition metal (1)
- Two-photon polymerization (1)
- USAXS (1)
- UV absorption (1)
- UV irradiation (1)
- UV photons (1)
- UV protection (1)
- UV-A (1)
- UV-B (1)
- UV-C (1)
- UV-Vis (1)
- Uncertainties (1)
- WAXS (1)
- Water filtration (1)
- Water management (1)
- Wide-range (1)
- X-ray (1)
- XAFS (1)
- Zeolites (1)
- Zeta potential (1)
- Zinc phosphate (1)
- Zwitterion (1)
- gold (1)
Organisationseinheit der BAM
- 6.5 Synthese und Streuverfahren nanostrukturierter Materialien (95) (entfernen)
Paper des Monats
- ja (4)
This paper reports the formation of zinc phosphate nanoparticles from the artificial digestion of zinc chloride. Initially, the formation of amorphous primary particles with a mean radius of 1.1 nm is observed, alongside the formation of larger, protein stabilized aggregates. These aggregates, with a radius of gyration of 37 nm, are observed after 5 minutes of exposure to artificial saliva and are shown to be colloidally stable for a minimum time of two weeks. The initially formed primary particles are thought to consist of amorphous zinc phosphate, which is then transformed into crystalline Zn3(PO4)2·4H2O over the course of two weeks. Our results demonstrate that the interaction of inorganic salts with bodily fluids can induce the formation of de novo nanoparticles, which in turn, provides insights into how zinc‐enriched foods may also facilitate the formation of nanoparticles upon contact with saliva. As such, this may be considered as an undesirable (bio)mineralization.
An artificial digestion of silver nitrate is reported. It is shown that AgSCN nanoparticles emerge from ionic silver in saliva and remain present during the entire digestion process. The particles were characterized by infrared spectroscopy and small- and wide-angle X-ray scattering (SAXS/WAXS) regarding their composition and size distribution.
Uptake and molecular impact of aluminum-containing nanomaterials on human intestinal caco-2 cells
(2018)
Aluminum (Al) is one of the most common elements in the earth crust and increasingly used in food, consumer products and packaging. Its hazard potential for humans is still not completely understood. Besides the metallic form, Al also exists as mineral, including the insoluble oxide, and in soluble ionic forms. Representatives of these three species, namely a metallic and an oxidic species of Al-containing nanoparticles and soluble aluminum chloride, were applied to human intestinal cell lines as models for the intestinal barrier. We characterized physicochemical particle parameters, protein corona composition, ion release and cellular uptake. Different in vitro assays were performed to determine potential effects and molecular modes of Action related to the individual chemical species. For a deeper insight into signaling processes, microarray transcriptome analyses followed by bioinformatic data analysis were employed. The particulate Al species showed different solubility in biological media. Metallic Al nanoparticles released more ions than Al2O3 nanoparticles, while AlCl3 showed a mixture of dissolved and agglomerated particulate entities in biological media. The protein corona composition differed between both nanoparticle species. Cellular uptake, investigated in transwell experiments, occurred predominantly in particulate form, whereas ionic Al was not taken up by intestinal cell lines. Transcellular transport was not observed. None of the Al species showed cytotoxic effects up to 200 mg Al/mL. The transcriptome analysis indicated mainly effects on oxidative stress pathways, xenobiotic metabolism and metal homeostasis. We have shown for the first time that intestinal cellular uptake of Al occurs preferably in the particle form, while toxicological effects appear to be ion-related.
Small-angle scattering is an increasingly common method for characterizing particle ensembles in a wide variety of sample types and for diverse areas of application. SASfit has been one of the most comprehensive and flexible curve-fitting programs for decades, with many specialized tools for various fields. Here, a selection of enhancements and additions to the SASfit program are presented that may be of great benefit to interested and advanced users alike: (a) further development of the technical basis of the program, such as new numerical algorithms currently in use, a continuous integration practice for automated building and packaging of the software, and upgrades on the plug-in system for easier adoption by third-party developers; (b) a selection of new form factors for anisotropic scattering patterns and updates to existing form factors to account for multiple scattering effects; (c) a new type of a very flexible distribution called metalog [Keelin (2016). Decis. Anal. 13, 243–277], and regularization techniques such as the expectation-maximization method [Dempster et al. (1977). J. R. Stat. Soc. Ser. B (Methodological), 39, 1–22; Richardson (1972) J. Opt. Soc. Am. 62, 55; Lucy (1974). Astron. J. 79, 745; Lucy (1994). Astron. Astrophys. 289, 983–994], which is compared with fits of analytical size distributions via the non-linear least-squares method; and (d) new structure factors, especially for ordered nano- and meso-scaled material systems, as well as the Ornstein–Zernike solver for numerical determination of particle interactions and the resulting structure factor when no analytical solution is available, with the aim of incorporating its effects into the small-angle scattering intensity model used for fitting with SASfit.
Negatively charged flat gold nanotriangles, formed in a vesicular template phase and separated by an AOT-micelle-based depletion flocculation, were reloaded by adding a cationic polyelectrolyte, that is, a hyperbranched polyethylenimine (PEI). Heating the system to 100 °C in the presence of a gold chloride solution, the reduction process leads to the formation of gold nanoparticles inside the polymer shell surrounding the nanoplatelets. The gold nanoparticle formation is investigated by UV−vis spectroscopy, small-angle X-ray scattering, and dynamic light scattering measurements in combination with transmission electron microscopy. Spontaneously formed gold clusters in the hyperbranched PEI shell with an absorption maximum at 350 nm grow on the surface of the nanotriangles as hemispherical particles with diameters of ∼6 nm. High-resolution micrographs show that the hemispherical gold particles are crystallized onto the {111} facets on the bottom and top of the platelet as well as on the edges without a grain boundary. Undulated gold nanoplatelet superstructures with special properties become available, which show a significantly modified performance in SERS-detected photocatalysis regarding both reactivity and enhancement factor.
Designing the shape and size of catalyst particles, and their interfacial charge, at the nanometer scale can radically change their performance. We demonstrate this with ceria nanoparticles. In aqueous media, nanoceria is a functional mimic of haloperoxidases, a group of enzymes that oxidize organic substrates, or of peroxidases that can degrade reactive oxygen species (ROS) such as H2O2 by oxidizing an organic substrate. We show that the chemical activity of CeO2−x nanoparticles in haloperoxidase- and peroxidaselike reactions scales with their active surface area, their surface charge, given by the ζ-potential, and their surface defects (via the Ce3+/Ce4+ ratio). Haloperoxidase-like reactions are controlled through the ζ-potential as they involve the adsorption of charged halide anions to the CeO2 surface, whereas peroxidase-like reactions without charged substrates are controlled through the specific surface area SBET. Mesoporous CeO2−x particles, with large surface areas, were prepared via template-free hydrothermal reactions and characterized by small-angle X-ray scattering. Surface area, ζ-potential and the Ce3+/Ce4+ ratio are controlled in a simple and predictable manner by the synthesis time of the hydrothermal reaction as demonstrated by X-ray photoelectron spectroscopy, sorption and ζ-potential measurements. The surface area increased with synthesis time, whilst the Ce3+/Ce4+ ratio scales inversely with decreasing ζ-potential. In this way the catalytic activity of mesoporous CeO2−x particles could be tailored selectively for haloperoxidase- and peroxidase-like reactions. The ease of tuning the surface properties of mesoporous CeO2x particles by varying the synthesis time makes the synthesis a powerful general tool for the preparation of nanocatalysts according to individual needs.
tNegatively charged ultrathin gold nanotriangles (AuNTs) were synthesized in a vesicular dioctyl sodiumsulfosuccinate (AOT)/phospholipid-based template phase. These “naked” AuNTs with localized surfaceplasmon resonances in the NIR region at about 1300 nm and special photothermal properties are ofparticular interest for imaging and hyperthermia of cancerous tissues. For these kinds of applicationsthe toxicity and the cellular uptake of the AuNTs is of outstanding importance. Therefore, this studyfocuses on the toxicity of “naked” AOT-stabilized AuNTs compared to polymer-coated AuNTs. Poly-meric coating consisted of non-modified hyperbranched poly(ethyleneimine) (PEI), maltose-modifiedpoly(ethyleneimine) (PEI-Mal) and heparin. The toxicological experiments were carried out with twodifferent cell lines (embryonic kidney carcinoma cell line HEK293T and NK-cell leukemia cell line YTS).This study revealed that the heparin-coating of AuNTs improved biocompatibility by a factor of 50 whencompared to naked AuNTs. Of note, the highest nontoxic concentration of the AuNTs coated with PEI andPEI-Mal is drastically decreased. Overall, this is mainly triggered by the different surface charges of poly-meric coatings. Therefore, AuNTs coated with heparin were selected to carry out uptake studies. Theirpromising high biocompatibility and cellular uptake may open future studies in the field of biomedicalapplications.
Metal nanoparticles have a substantial impact across diferent felds of science, such as photochemistry, energy conversion, and medicine. Among the commonly used nanoparticles, silver nanoparticles are of special interest due to their antibacterial properties and applications in sensing and catalysis. However, many of the methods used to synthesize silver nanoparticles often do not result in well-defned products, the main obstacles being high polydispersity or a lack of particle size tunability. We describe an automated approach to on-demand synthesis of adjustable particles with mean radii of 3 and 5 nm using the polyol route. The polyol process is a promising route for silver nanoparticles e.g., to be used as reference materials. We characterised the as-synthesized nanoparticles using small-angle X-ray scattering, dynamic light scattering and further methods, showing that automated synthesis can yield colloids with reproducible and tuneable properties.
Iron oxides used as food colorants are listed in the European Union with the number E172. However, there are no specifications concerning the fraction of nanoparticles in these pigments.
Here, seven E172 products were thoroughly characterized. Samples of all colors were analyzed with a Broad spectrum of methods to assess their physico-chemical properties. Small-Angle X-ray Scattering (SAXS), Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM), zeta-potential, Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), X-ray diffraction (XRD), Brunauer-Emmett-Teller analysis (BET), Asymmetric Flow Field-Flow Fractionation (AF4) and in vitro cell viability measurements were used.
Nanoparticles were detected in all E172 samples by TEM or SAXS measurements. Quantitative results from both methods were comparable. Five pigments were evaluated by TEM, of which four had a size median below 100 nm, while SAXS showed a size median below 100 nm for six evaluated pigments. Therefore, consumers May be exposed to iron oxide nanoparticles through the consumption of food pigments.
Herein, we provide a "systems architecture"-like overview and detailed discussions of the methodological and instrumental components that, together, comprise the "MOUSE" project (Methodology Optimization for UltrafineStructure Exploration). The MOUSE project provides scattering information on a wide variety of samples, with traceable dimensions for both the scattering vector (q) and the absolute scattering cross-section (I). The measurable scattering vector-range of 0.012≤ q (nm-1) ≤ 92, allows information across a hierarchy of structures with dimensions ranging from ca. 0.1 to 400 nm. In addition to details that comprise the MOUSE project, such as the organisation and traceable aspects, several representative examples are provided to demonstrate its flexibility. These include measurements on alumina membranes, the tobacco mosaic virus, and dual-source information that overcomes fluorescence limitations on ZIF-8 and iron-oxide-containing carbon catalyst materials.