Nano
Filtern
Dokumenttyp
- Zeitschriftenartikel (347)
- Vortrag (338)
- Posterpräsentation (100)
- Forschungsdatensatz (50)
- Sonstiges (20)
- Beitrag zu einem Tagungsband (16)
- Buchkapitel (10)
- Beitrag zu einem Sammelband (10)
- Forschungsbericht (9)
- Zeitschriftenheft (Herausgeberschaft für das komplette Heft) (6)
Sprache
- Englisch (870)
- Deutsch (52)
- Spanisch (2)
- Mehrsprachig (1)
Schlagworte
- Nanoparticles (124)
- Nano (70)
- SAXS (64)
- XPS (60)
- Laser-induced periodic surface structures (LIPSS) (59)
- Fluorescence (53)
- Quantum yield (51)
- Electron microscopy (48)
- Nanoparticle (46)
- X-ray scattering (46)
Organisationseinheit der BAM
- 6 Materialchemie (656)
- 6.1 Oberflächen- und Dünnschichtanalyse (345)
- 1 Analytische Chemie; Referenzmaterialien (184)
- 1.2 Biophotonik (159)
- 6.6 Physik und chemische Analytik der Polymere (134)
- 6.5 Synthese und Streuverfahren nanostrukturierter Materialien (129)
- 6.2 Material- und Oberflächentechnologien (90)
- 5 Werkstofftechnik (61)
- 4 Material und Umwelt (46)
- 5.4 Multimateriale Fertigungsprozesse (33)
- 6.3 Strukturanalytik (27)
- 7 Bauwerkssicherheit (27)
- 4.2 Material-Mikrobiom Wechselwirkungen (26)
- 9 Komponentensicherheit (25)
- 9.5 Tribologie und Verschleißschutz (20)
- 4.1 Biologische Materialschädigung und Referenzorganismen (19)
- 7.5 Technische Eigenschaften von Polymerwerkstoffen (17)
- 1.5 Proteinanalytik (14)
- 6.7 Materialsynthese und Design (14)
- 8 Zerstörungsfreie Prüfung (14)
- 5.1 Mikrostruktur Design und Degradation (13)
- 5.6 Glas (10)
- 8.5 Röntgenbildgebung (9)
- VP Vizepräsident (9)
- VP.1 eScience (9)
- 1.9 Chemische und optische Sensorik (8)
- 6.0 Abteilungsleitung und andere (7)
- 1.0 Abteilungsleitung und andere (5)
- 7.6 Korrosion und Korrosionsschutz (5)
- 1.1 Anorganische Spurenanalytik (4)
- 7.4 Baustofftechnologie (4)
- 1.8 Umweltanalytik (3)
- P Präsident (3)
- 1.7 Organische Spuren- und Lebensmittelanalytik (2)
- 3 Gefahrgutumschließungen; Energiespeicher (2)
- 5.2 Metallische Hochtemperaturwerkstoffe (2)
- 5.5 Materialmodellierung (2)
- 8.0 Abteilungsleitung und andere (2)
- 9.0 Abteilungsleitung und andere (2)
- 9.4 Integrität von Schweißverbindungen (2)
- P.0 Präsident und andere (2)
- 1.3 Instrumentelle Analytik (1)
- 1.4 Prozessanalytik (1)
- 2 Prozess- und Anlagensicherheit (1)
- 2.1 Sicherheit von Energieträgern (1)
- 3.0 Abteilungsleitung und andere (1)
- 3.5 Sicherheit von Gasspeichern (1)
- 4.5 Kunst- und Kulturgutanalyse (1)
- 5.0 Abteilungsleitung und andere (1)
- 5.3 Polymere Verbundwerkstoffe (1)
- 6.4 Materialinformatik (1)
- 7.1 Baustoffe (1)
- 7.2 Ingenieurbau (1)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (1)
- 8.4 Akustische und elektromagnetische Verfahren (1)
- 8.6 Faseroptische Sensorik (1)
- 9.2 Versuchsanlagen und Prüftechnik (1)
- 9.3 Schweißtechnische Fertigungsverfahren (1)
- MP Mitglied des Präsidiums (1)
- MP.0 Mitglied des Präsidiums und andere (1)
- PST Präsidiale Stabsstelle (1)
Paper des Monats
- ja (15)
Hydrogen features a very high specific energy density and is therefore a promising candidate for clean fuel from renewable resources. Water electrolysis can convert electrical energy into storable and transportable hydrogen gas. Under acidic conditions, platinum is the most active and stable monometallic catalyst for the hydrogen evolution reaction (HER). Yet, platinum is rare and needs to be used efficiently. Here, we report a synthesis concept for colloidal bimetallic platinum–ruthenium and rhodium–ruthenium nanoparticles (PtRuNP, RhRuNP) and their incorporation into ordered mesoporous carbon (OMC) films. The films exhibit high surface area, good electrical conductivity and well-dispersed nanoparticles inside the mesopores. The nanoparticles retain their size, crystallinity and composition during carbonization. In the hydrogen evolution reaction (HER), PtRuNP/OMC catalyst films show up to five times higher activity per Pt than Pt/C/Nafion® and PtRu/C/Nafion® reference catalysts.
We synthesized a generation of water-soluble, atomically precise gold nanoclusters (Au NCs) with anisotropic Surface containing a short dithiol pegylated chain (AuMHA/TDT). The AuMHA/TDT exhibit a high brightness (QY ∼ 6%) in the shortwave infrared (SWIR) spectrum with a detection above 1250 nm.
Furthermore, they show an extended half-life in blood (t1/2ß = 19.54 ± 0.05 h) and a very weak accumulation in organs. We also developed a non-invasive, whole-body vascular imaging system in the SWIR window with high-resolution, benefiting from a series of Monte Carlo image processing. The imaging process enabled to improve contrast by 1 order of magnitude and enhance the spatial Resolution by 59%. After systemic administration of these nanoprobes in mice, we can quantify vessel complexity in depth (>4 mm), allowing to detect very subtle vascular disorders non-invasively in bone morphogenetic protein 9 (Bmp9)-deficient mice. The combination of these anisotropic surface charged Au NCs plus an improved SWIR imaging device allows a precise mapping at high-resolution and an in depth understanding of the organization of the vascular network in live animals.
Supramolecular copolymerization driven by integrative self-sorting of hydrogen-bonded rosettes
(2020)
Molecular recognition to preorganize noncovalently polymerizable supramolecular complexes is a characteristic process of natural supramolecular polymers, and such recognition processes allow for dynamic self-alteration, yielding complex polymer systems with extraordinarily high efficiency in their targeted function. We herein show an example of such molecular recognition-controlled kinetic assembly/disassembly processes within artificial supramolecular polymer systems using six-membered hydrogen-bonded supramolecular complexes (rosettes). Electron-rich and poor monomers are prepared that kinetically coassemble through a temperature-controlled protocol into amorphous coaggregates comprising a diverse mixture of rosettes. Over days, the electrostatic interaction between two monomers induces an integrative self-sorting of rosettes. While the electron-rich monomer inherently forms toroidal homopolymers, the additional electrostatic interaction that can also guide rosette association allows helicoidal growth of supramolecular copolymers that are comprised of an alternating array of two monomers. Upon heating, the helicoidal copolymers undergo a catastrophic transition into amorphous coaggregates via entropy-driven randomization of the monomers in the rosette.
The quantitative difference in the antibacterial response was measured for pine rosin and propolis against Staphylococcus aureus ATCC 12598. The activity was studied for fibrous networks that form entirely bio-based cellulose-acetate (CA) materials. The analysis considers the effects of bacterial input, additive dosage, solvent type, variation in preparation, as well as the effect of storage time. Based on the results, the electrospun network structure is dependent on the solvent and the concentration of rosin and propolis. Both rosin and propolis improved the cellulose acetate solution processability, yet they formed beads at high concentrations. Rosin and propolis created strong antibacterial properties when these material systems were immersed in the liquid for 24 h at room temperature. The response remained visible for a minimum of two months. The electrospun networks of water and DMAc solvent systems with 1 to 5 wt% rosin content were clearly more efficient (i.e., decrease of 4 to 6 logs in colony forming units per mL) than the propolis networks, even after two months. This efficiency is likely due to the high content of abietic acids present in the rosin, which is based on the Fourier transform infrared spectra. The results of the additional analysis and cell cultivation with dermal fibroblast cells indicated an impairing effect on skin tissue by the rosin at a 1 wt% concentration compared to the pure CA fibers.
Aluminum (Al) can be taken up from food, packaging, or the environment and thus reaches the human gastrointestinal tract. Its toxic potential after oral uptake is still discussed. The fate of different solid and ionic Al species during the passage through the digestive tract is the focus of this research, as well as the cellular effects caused by these different Al species. The present study combines the physicochemical processing of three recently studied Al species (metallic Al0, mineral Al2O3, and soluble AlCl3) in artificial digestion fluids with in vitro cell systems for the human intestinal barrier. Inductively coupled plasma mass spectrometry (ICP-MS) and small-angle X-ray scattering (SAXS) methods were used to characterize the Al species in the artificial digestion fluids and in cell culture medium for proliferating and differentiated intestinal Caco-2 cells. Cytotoxicity testing and cellular impedance measurements were applied to address the effects of digested Al species on cell viability and cell proliferation. Microarray-based transcriptome analyses and quantitative real-time PCR were conducted to obtain a deeper insight into cellular mechanisms of action and generated indications for cellular oxidative stress and an influence on xenobiotic metabolism, connected with alterations in associated signaling pathways. These cellular responses, which were predominantly caused by formerly ionic Al species and only at very high concentrations, were not impacted by artificial digestion. A two-directional conversion of Al between ionic species and solid particles occurred throughout all segments of the gastrointestinal tract, as evidenced by the presence of nanoscaled particles. Nevertheless, this presence did not increase the toxicity of the respective Al species.
This book by Scrivener Publishing contains 14 chapters written by 82 leading scientists, experienced in the field of coatings. They demonstrate mechanisms, usage and manipulation of cutting‐edge coating methods. Each chapter is well structured and ends with a conclusion, highlighting the content. The book is divided into 3 parts: “Materials and Methods”, “Coating Materials Nanotechnology” and “Advanced Coating Technology and Applications”.
Finally, this book provides a comprehensive insight into innovative research in advanced coating materials and state‐of‐the‐art technologies, without being a real textbook. It fulfills its intension of being beneficial both for technicians and scientists.
Laser material processing is an emerging technology that generates surface functionalities on the basis of optical, mechanical, or chemical properties. In the form of laser surface texturing (LST), it has attracted a remarkable amount of research to tailor surface properties towards various tribological applications. The main advantages of this single-step, laser-based technology are the contactless machining, featuring a high flexibility, efficiency, and speed, along with the excellent quality of the processed products. LST can be applied precisely localized to sub-micrometric areas, but, via laser beam scanning, it is also feasible for structuring large surface areas at the square meter size.
This Special Issue focuses on the latest developments concerning the tribological performance of laser-generated periodic surface nano- and microstructures and their applications. This includes the laser-based processing of different surface patterns, such as “self-organized” laser-induced periodic surface structures (LIPSS, ripples), grooves, micro-spikes, hierarchical hybrid nano-/micro-structures, microfeatures generated by direct laser interference patterning (DLIP), or even dimples or other topographic geometries shaped by direct laser modification or ablation. The applications of these periodically nano- and micro-patterned surfaces may improve the lubricated or non-lubricated tribological performance of surfaces in conformal and even non-conformal contact through a reduction of wear, a variation of the coefficient of friction, altered load carrying capacity, etc., resulting in energy saving, improved reliability, increased lifetimes as well as durability, leading in turn to extended maintenance intervals/reduced down-time. This can be beneficial in terms of bearings, gears, engines, seals, cutting tools, or other tribological components. Fundamental aspects addressed may involve the investigation of the relevant physical and chemical effects accompanying the laser-generated nano- and microscale topographies, such as alterations of the material structures, the hardness, superficial oxidation, the role of additives contained in lubricants, surface wettability, micro-hydrodynamic effects, etc.
For this Special Issue we aim to attract both academic and industrial researchers and would like to provide a bridge between research in the fields of tribology and laser material processing in order to foster the current knowledge and present new ideas for future applications and new technologies.
Laser material processing is an emerging technology that generates surface functionalities on the basis of optical, mechanical, or chemical properties. In the form of laser surface texturing (LST), it has attracted a remarkable amount of research to tailor surface properties towards various tribological applications. The main advantages of this single-step, laser-based technology are the contactless machining, featuring a high flexibility, efficiency, and speed, along with the excellent quality of the processed products. LST can be applied precisely localized to sub-micrometric areas, but, via laser beam scanning, it is also feasible for structuring large surface areas at the square meter size.
This Special Issue focuses on the latest developments concerning the tribological performance of laser-generated periodic surface nano- and microstructures and their applications. This includes the laser-based processing of different surface patterns, such as “self-organized” laser-induced periodic surface structures (LIPSS, ripples), grooves, micro-spikes, hierarchical hybrid nano-/micro-structures, microfeatures generated by direct laser interference patterning (DLIP), or even dimples or other topographic geometries shaped by direct laser modification or ablation. The applications of these periodically nano- and micro-patterned surfaces may improve the lubricated or non-lubricated tribological performance of surfaces in conformal and even non-conformal contact through a reduction of wear, a variation of the coefficient of friction, altered load carrying capacity, etc., resulting in energy saving, improved reliability, increased lifetimes as well as durability, leading in turn to extended maintenance intervals/reduced down-time. This can be beneficial in terms of bearings, gears, engines, seals, cutting tools, or other tribological components. Fundamental aspects addressed may involve the investigation of the relevant physical and chemical effects accompanying the laser-generated nano- and microscale topographies, such as alterations of the material structures, the hardness, superficial oxidation, the role of additives contained in lubricants, surface wettability, micro-hydrodynamic effects, etc.
For this Special Issue we aim to attract both academic and industrial researchers and would like to provide a bridge between research in the fields of tribology and laser material processing in order to foster the current knowledge and present new ideas for future applications and new technologies.
Nanoparticle suspensions were microprinted onto TEM grids for subsequent analysis by SEM/TSEM and evaluation of particle numbers using Image J software. Various nanoparticle types, concentrations and printing conditions (temperature, rel. humidity) were evaluated in order to determine the optimal conditions for producing a uniform distribution of particles on the substrate and eliminating the coffee ring effect.