Ingenieurwissenschaften und zugeordnete Tätigkeiten
Filtern
Dokumenttyp
- Posterpräsentation (55) (entfernen)
Referierte Publikation
- nein (55)
Schlagworte
- Boehmite (7)
- DNA (5)
- Dielectric spectroscopy (5)
- Dosimetry (5)
- Geant4 (5)
- LEE (5)
- Microdosimetry (5)
- Microplastics (5)
- AuNP (4)
- DNA damage (4)
- Energy deposit (4)
- Geant4-DNA (4)
- MCS (4)
- Microplastic (4)
- Monte-Carlo simulation (4)
- Nanocomposites (4)
- Radiation damage (4)
- Radiationtherapy (4)
- Radioactive decay (4)
- Bending modulus (3)
- Beta decay (3)
- Brachytherapy (3)
- Cancer treatment (3)
- Carbon nanotubes (3)
- Clustered nanoparticles (3)
- Conductivity (3)
- Epoxy (3)
- Gold Nanoparticles (3)
- Livermore model (3)
- Low energy electrons (3)
- Micropatterning (3)
- NP (3)
- Nanocomposite (3)
- Nanofibers (3)
- OH radical (3)
- Penelope model (3)
- Polydopamine (3)
- Polymer 3R (3)
- Polymer blends (3)
- Polypropylene (3)
- Radiation therapy (3)
- Radiolysis (3)
- Rigidity (3)
- Simulation (3)
- Specific heat spectroscopy (3)
- TOPAS (3)
- TOPAS-nbio (3)
- Thin polymeric films (3)
- Two-photon polymerisation (3)
- particle scattering (3)
- AFM (2)
- Adsorbed Layer (2)
- Aktivkohle (2)
- Cycloalyphatic epoxy oligosiloxane (2)
- Degradation (2)
- Ellipsometry (2)
- Exchange interaction (2)
- Ferromagnetism (2)
- Ionic Liquid crystals (2)
- LLG (2)
- Landau Lifshitz equation (2)
- Magnetic moment (2)
- Magnetic nanoparticles (2)
- Micromagnetism (2)
- Nanoconfinement (2)
- OOMMF (2)
- Object oriented micromagnetic framework (2)
- Polycarbonate (2)
- Protein (2)
- Proteins (2)
- Radiotherapy (2)
- Resonance frequency (2)
- Stochastic Landau Lifshitz Gilbert equation (2)
- TED-GC/MS (2)
- Thermogravimetrie (2)
- Thin Films (2)
- beta particle (2)
- Adsorbed layer (1)
- Atomic Force Microscopy (1)
- Atomic force microscopy (1)
- Beta particle (1)
- Bio-SAXS (1)
- BioSAXS (1)
- Boehmite alumina (1)
- Broadband dielectric spectroscopy (1)
- CEO (1)
- CUSP (1)
- Columnar liquid crystals (1)
- Compatible solute (1)
- Confined Columnar Liquid Crystals (1)
- Cosolute (1)
- DRIFTS (1)
- Direct laser writing (1)
- Discotic Liquid Crystals (1)
- Dynamics (1)
- Ectoin (1)
- Ectoine (1)
- FTIR (1)
- FTIR spectroscopy (1)
- G5P (1)
- GVP (1)
- Gene five protein (1)
- Glass transition (1)
- Gold Nanoparticle (1)
- Growth Kinetics (1)
- HV cable accessories (1)
- Harmonisation in microplastics (1)
- Hydroxyectoine (1)
- ILC (1)
- Interpenetrating polymer network (1)
- Interpenetrating polymer networks (1)
- Ionizing radiation damage (1)
- Material selection (1)
- McSAS3 (1)
- Median lethal energy deposit (1)
- Micropatterned dry adhesive (1)
- Microplastics in milk (1)
- Microplastics sampling (1)
- Monte-Carlo simulations (1)
- Multiphoton Lithography (1)
- Multiphoton lithography (1)
- Nanomechanics (1)
- Nanoparticle (1)
- Nanoplastics (1)
- OH Radical (1)
- OH radical scavenger (1)
- OH radicals (1)
- Osmolyte (1)
- Particle scattering (1)
- Particle scattering simulations (1)
- Phosphorus (1)
- Photocuring (1)
- Polyethylene (1)
- Polyethylene Terephtalate (1)
- Polyethylene glycol diacrylate (1)
- Polymer Hydrolysis (1)
- Polymer nanocomposites (1)
- Polymeric membrane (1)
- Polymers (1)
- Polymers of intrinsic microporosity (1)
- Protein unfolding (1)
- Proximatanalyse (1)
- Py-GC/MS (1)
- REACH (1)
- ROS (1)
- Radical Scavenger (1)
- Radical scavenger (1)
- Reference materials (1)
- Resonance (1)
- Rigid amorphous fraction (1)
- SAXS (1)
- SEM (1)
- Sample preparation (1)
- Self-healing (1)
- Self-healing silicone rubber (1)
- Si wafer filter (1)
- Single-stranded DNA-binding proteins (1)
- Small-angle xray scattering (1)
- Smart materials (1)
- Soil (1)
- Sulfur (1)
- TED-GC-MS (1)
- TGA-FTIR (1)
- TMDSC (1)
- Temeprature scaling (1)
- Temperature scaling (1)
- Textile fibres (1)
- Themal Transitions (1)
- Thermoplastic Polyurethane (1)
- Thin films (1)
- Thin polymer films (1)
- Topas (1)
- Topas-MC (1)
- Topas-nBio (1)
- Trinkwasser (1)
- Two photon polymerisation (1)
- Wasseraufbereitung (1)
- X-ray scattering (1)
- XPS (1)
- Zersetzungsgasanalyse (1)
- low energy electrons (1)
- ssDNA (1)
- µ-FTIR (1)
- µ-Raman (1)
Organisationseinheit der BAM
- 6.6 Physik und chemische Analytik der Polymere (55) (entfernen)
Interactions between a polymer and a substrate interface play a vital role in understanding the improvement in thin film material properties as well as serving as a model for nanocomposites. For any non-repulsive polymer-substrate interactions, polymer segments form an irreversibly adsorbed layer and show a slowdown in the glassy dynamics and thus an increase in the thermal glass transition temperature compared to the bulk-like values. The growth kinetics of the adsorbed layer showed a deviation for both poly (bisphenol-A carbonate) (PBAC) and polysulfone (PSU), two bulky polymers containing a functional group (phenyl ring) in the backbone.
Since microplastics (MPs) can be found everywhere and are becoming a problem of high concern, it is necessary to understand their occurrence and fate in the environment. However, to obtain data of high quality is very challenging, since measurement operating procedures differ from laboratory to laboratory. Currently, there are no standardized methods to analyze microplastics. One promissing possibility to adress standardization of the methodology and operating procedures are interlaboratory comparisons (ILCs). In this contribution we report the first results of an ILC on microplastic detection methods organized under the pre-stantdardisation plattform of VAMAS (www.vamas.org/twa45/) as Project 2 “Development of standardized methodologies for characterisation of microplastics with microscopy and spectroscopy methods”, within the Technical Working Area TWA 45 “Micro and Nano Plastics in the Environment”. The ILC has gathered 84 participants all over the world representing all continents. BAM, as the project leader, produced a set of reference microplastic materials, which have been distributed to all the participants together with the measurement protocols and reporting data templates.
Microplastic and nanoplastic particles (MNP) are spread all over the world in various types, shapes and sizes making it very challenging to accurately analyse them. Each sampling procedure, sample preparation method and detection technique needs suitable reference materials to validate the method for accurate results. Furthermore, the effects of these MNPs should be evaluated by risk and hazard assessment with test particles close to reality. To better understand MNP behavior and aid in clarification of their interactions with organisms, we produced several MNP materials by top-down procedure and characterized their properties. Since surface properties mostly determine particles’ toxicity, the aim of the present study was to determine which functional groups are present on MNPs and how the surface can be affected by the production process and particle’s environment.
Monitoring of microplastics in food matrices is crucial to determinate the human exposure. By direct ingestion microplastics could be released in the food during the production, through packaging and by consumer’s use. The absence of standard methods to quantify and detect different size range and type of microplastics has led to difficult and time consuming procedural steps, poor accuracy and lack of comparability. In this work, matrix characterization and laboratory experiments were used to investigate the efficiency of sample preparation in milk powder. This information is crucial to compile a standard procedure for sample preparation and digestion of common milk powder to detect different particle sizes and types of polymers. Charaterisation is done by TGA and TOC measurements.
Multiphoton lithography (MPL), an emerging microfabrication technique, shows great potential in a variety of applications ranging from tissue engineering to soft micro-robotics. Fabricated micro-objects often are expected to undergo shape morphing or bending. Furthermore, ensuring precise property tuning becomes detrimental for the functionality of MPL microstructures. Herein, we present novel MPL materials based on interpenetrating networks (IPNs), which effectively combine the advantages of acrylate and epoxy thermoset systems. A library of 3D MPL IPN microstructures with high 3D structural stability and tailored thermal and micromechanical properties is achieved. MPL laser velocity and fabrication power can be used to tune the morphology and therefore properties of IPN. New IPN microstructures with materials Young's moduli of 4 to 6 MPa demonstrate susceptibility to deformation with high to fully elastic response. Such soft elastic materials hold immense promise within morphable microsystems, soft micro-robotics and cell engineering applications.
Text Multiphoton lithography (MPL) has recently attracted significant research interest as a versatile tool capable of producing 2D and 3D micro- and nanoscopic features with high spatial resolution. The integrity of MPL microstructures, or their ability to respond to external stimuli, is of critical importance. However, achieving the desired properties of fabricated microcomponents for a specific application remains a challenge.
In this work, we present new MPL materials based on epoxy-acrylate interpenetrating networks (IPNs). We aim at 3D microstructures, whose properties can be easily tuned by varying the ratio of the IPN components and fabrication parameters (Figure 1). The resulting library of 3D microstructures was investigated for their thermal and mechanical properties using highly-sensitive space-resolved methods. Flash scanning calorimetry revealed the influence of both, IPN composition and fabrication parameters, on glass transition temperature and material fragility. AFM force-distance curve and intermodulation methods were used to characterize the mechanical properties with a lateral resolution of 1 micron and 4 nm, respectively. The deformation, stiffness and elastic behavior are discussed in detail in relation to the morphology. Moreover, we found that some 3D IPN microstructures exhibit fully elastic behavior. Our funding encourages the further development of IPN systems as versatile and easily tunable MPL materials.
Dose enhancement by gold nanoparticles (AuNP) increases the biological effectiveness of radiation damage in biomolecules and tissue. To apply them effectively during cancer therapy their influence on the locally delivered dose has to be determined.[1] Hereby, the AuNP locations strongly influence the energy deposit in the nucleus, mitochondria, membrane and the cytosol of the targeted cells. To estimate these effects, particle scattering simulations are applied. In general, different approaches for modeling the AuNP and their distribution within the cell are possible. In this work, two newly developed continuous and discrete-geometric models for simulations of AuNP in cells are presented. [2] These models are applicable to simulations of internal emitters and external radiation sources. Most of the current studies on AuNP focus on external beam therapy. In contrast, we apply the presented models in Monte-Carlo particle scattering simulations to characterize the energy deposit in cell organelles by radioactive 198AuNP. They emit beta and gamma rays and are therefore considered for applications with solid tumors. Differences in local dose enhancement between randomly distributed and nucleus targeted nanoparticles are compared. Hereby nucleus targeted nanoparticels showed a strong local dose enhancement in the radio sensitive nucleus. These results are the foundation for ongoing experimental work which aims to obtain a mechanistic understanding of cell death induced by radioactive 198Au.
The movement of the macroscopic magnetic moment in ferromagnetic systems can be described by the Landau-Lifshitz (LL) or Landau-Lifshitz-Gilbert (LLG) equation. These equations are strictly valid only at absolute zero temperature. To include temperature effects a stochastic version of the LL or LLG equation for a spin density of one per unit cell can be used instead. To apply the stochastic LL to micromagnetic simulations, where the spin density per unit cell is generally higher, a conversion regarding simulation cell size and temperature has to be established. Based on energetic considerations, a conversion for ferromagnetic bulk and thin film systems is proposed. The conversion is tested in micromagnetic simulations which are performed with the Object Oriented Micromagnetic Framework (OOMMF). The Curie temperatures of bulk Nickel, Cobalt and Iron systems as well as Nickel thin-film systems with thicknesses between 6.3 mono layer (ML) and 31ML are determined from micromagnetic simulations. The results show a good agreement with experimentally determined Curie temperatures of bulk and thin film systems when temperature scaling is performed according to the presented model.
Dose enhancement by gold nanoparticles (AuNP) increases the biological effectiveness of radiation damage in biomolecules and tissue.
To apply them effectively during cancer therapy their influence on the locally delivered dose has to be determined. Hereby, the AuNP locations strongly influence the energy deposit in the nucleus, mitochondria, membrane and the cytosol of the targeted cells. In this work, two newly developed continuous and discrete-geometric models for simulations of AuNP in cells are presented. We apply the presented models in Monte-Carlo particle scattering simulations to characterize the energy deposit in cell organelles by radioactive 198AuNP. They emit beta and gamma rays and are therefore considered for applications
with solid tumors. Differences in local dose enhancement between randomly distributed and nucleus targeted nanoparticles are compared.
Hereby nucleus targeted nanoparticels showed a strong local dose enhancement in the radio sensitive nucleus.
Determining thermal transitions in thin polymer layers by means of spectroscopic ellipsometry
(2023)
Thin polymer layers have enormous technical significance as polymer coatings on materials are very cost-effective for tailoring properties of surfaces. Apart from technical aspects in their use, thin polymer layers can be used to determine dimensional aspects in properties of material, such as confinement effects.
In this work, we investigated several different polymer layer materials and determined their glass transition region by means of temperature-dependent spectroscopic ellipsometry. We have optimised our fitting procedure of the ellipsometric data produced in temperature ramp experiments. By this, we could measure the dependence of Tg on the layer thickness in a wide variety of thickness values, proving the existence of confinement effects in the investigated systems. We compare numerical methods for determining the location of the glass transition and discuss the possibilities of different analysis methods when determining thermal transitions. We also discuss the simultaneous existence of these transitions and annealing effects and the implications on the accuracy of the determined data.