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Following the recommendation of the European Chemicals Agency, on 25 September 2023 the European Commission passed a comprehensive new regulation to reduce emissions of microplastics (MP) into the environment, which includes the sale and use of intentionally added MP.1,2 This also applies to the application of synthetic rubber granulate infill in artificial turf systems and will ultimately have an impact on recreational sports. In Germany, rubber granulate made of ethylene-propylene-diene-monomer rubber (EPDM) is currently predominantly used. So far, there is no sufficient database for estimating MP emissions from artificial turf pitches into the environment and thus their relevance as a source of MP pollution.3 This topic is controversially discussed due to the complexity of sampling and analytics. To close this research gap, this project has the goal to determine mass balances for the emissions of MP from artificial turf pitches to allow an estimation of the amount of MP released per artificial turf pitch and year.
Within this study, MP emissions of three artificial turf scenarios at different time states (unaged, artificially aged and real-time aged) are compared: the past (old turf: fossil based, synthetic infill), present (most commonly installed in Europe: fossil based, EPDM infill), and the future (turf with recycled gras fibres, no synthetic infill). To simulate the outdoor weathering during the lifespan of an artificial turf of approx. 15 years, brand-new artificial turf and EPDM rubber granulate were accelerated aged by means of UV weathering and mechanical stress. Potential MP emissions into surface and groundwater are simulated by lysimeter and shake experiments. MP mass contents are subsequently determined by Thermal Extraction Desorption Gas Chromatography/Mass Spectrometry. Using special microfilter crucibles allows the estimation of the particle sizes of the emitted MP, which is a fundamental requirement for an assessment of potential health hazards for humans.
Bakterielle Biofilme stellen in medizinischen und industriellen Bereichen ein ernsthaftes Problem dar. Eine der größten gesellschaftlichen Herausforderungen liegt in der zunehmenden Resistenz von Bakterien gegen Biozide, die bei antimikrobiellen Behandlungen eingesetzt werden, z.B. durch übermäßigen Einsatz in Medizin, Industrie und Landwirtschaft oder durch Reinigung und Desinfektion in Privathaushalten. Daher sind neue effiziente bakterienabweisende Strategien, die den Einsatz von Bioziden vermeiden, dringend erforderlich.
Ein vielversprechender Weg zur Erzielung bakterienabweisender Oberflächen liegt in der berührungslosen und aseptischen großflächigen Laserbearbeitung von technischen Oberflächen. Maßgeschneiderte Oberflächentexturen, ermöglicht durch verschiedene Laserbearbeitungsstrategien, die zu topographischen Skalen im Bereich von Nanometern bis Mikrometern führen, können eine Lösung für diese Herausforderung darstellen.
In dem Vortrag wird ein Überblick über den aktuellen Stand der Technik bei der subtraktiven Texturierung von Laseroberflächen zur Kontrolle der Biofilmbildung bei verschiedenen Bakterienstämmen und in unterschiedlichen Umgebungen gegeben. Auf der Grundlage spezifischer Eigenschaften von Bakterien und laserbearbeiteten Oberflächen werden die Herausforderungen antimikrobieller Oberflächendesigns erörtert und zukünftige Richtungen aufgezeigt.
Calcium sulfate hemihydrate (CaSO4ᐧ0.5H2O), also known as bassanite, has been used as a precursor to produce gypsum (dihydrate, CaSO4ᐧ2H2O) for various construction and decorative purposes since prehistoric times. The main route to obtain hemihydrate is a thermal treatment of gypsum at temperatures typically between 150 °C and 200 °C to remove some of the structural water.
In this contribution, we introduce (Fig. 1) a more efficient and sustainable method (T < 100 °C) that enables the direct, rapid, and reversibly conversion of gypsum to bassanite using reusable high salinity aqueous solutions (brines with c[NaCl] > 4 M). The optimum conditions for the efficientproduction of bassanite in a short time (< 5 min) involve the use of brines with c(NaCl) > 4 M and maintaining a temperature, T > 80 °C. When the solution containing bassanite crystals is cooled down to around room temperature, eventually gypsum is formed. When the temperature is raised again to T > 80 °C, bassanite is rapidly re-precipitated. This contrasts with the typical behaviour of the bassanite phase in low salt environments.
Traditionally, hemihydrate is obtained through a solid state thermal treatment because bassanite is considered to be metastable with respect to gypsum and anhydrite in aqueous solutions, and therefore gypsum-to-bassanite conversion should not occur in water. Its very occurrence actually contradicts numerical thermodynamic predictions regarding solubility of calcium sulfate phases. By following the evolution of crystalline phases with in situ and time-resolved X-ray diffraction/scattering and Raman spectroscopy, we demonstrated that the phase stability in brines at elevated temperatures is inaccurately represented in the thermodynamic databases. Most notably for c(NaCl) > 4 M, and T > 80 °C gypsum becomes readily more soluble than bassanite, which induces the direct precipitation of the latter from gypsum. The fact that these transformations are controlled by the solution provides extensive opportunities for precise manipulation of crystal formation. Our experiments confirmed that bassanite remained the sole crystalline structure for many hours before reverting into gypsum. This property is extremely advantageous for practical processing and efficient crystal extraction in industrial scenarios.
Regional standardisation activities and how VAMAS can help in any way to promote activities are reported.
Activities related to organisational updates, government initiatives/priorities (especially related to Materials), details of any strategy documents publicly available, networks within Germany and how we engage are presented.
Surfaces of metallic copper and copper alloys effectively inactivate microorganisms and viruses. However, the exact inactivation mode is still under debate. Main factors are assumed to include direct contact with the metallic surface, influx of Cu(I)/Cu(II) ions and the generation of reactive oxygen species (ROS). Laser-induced periodic surface structures (LIPSS) are frequently reported to act antibacterial, mainly by prevention of bacterial adhesion due to a limited number of possible adhesion points or by increasing the overall surface of intrinsically antibacterial materials. In time-kill experiments with E. coli and S. aureus we analyzed the impact of LIPSS on the toxicity of metallic copper and brass. We also conducted ROS accumulation assays and conclude that the application of LIPSS is not generally straight forward to obtain or improve antibacterial surfaces. Thus, the antibacterial effects of LIPPS.
Bacteria are ubiquitous and colonize all types of surfaces, including those in close proximity to humans, such as skin, food, and everyday objects. This raises the question of whether their presence represents a problem to be mitigated or a potential source of benefit to be harnessed, thereby stimulating scientific inquiry into the role of surface-associated bacteria in diverse domains ranging fromhuman health to industrial biotechnology. Aim: The objective of this project is to explore the impact of modifying surface topography on bacterial adhesion behavior. By manipulating the physical characteristics of the substrate, the attachment and detachment dynamics of bacteria can potentially be modified, leading to novel strategies for controlling bacterial colonization in various applications, such as medical devices. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were tested on LIPSS-covered Fused Silica samples.
This 6 minute long MP4-video presents some key results of the European research project "BioCombs4Nanofibers" to the broader public. Inspired by nature, some concepts of certain types of spiders are transferred to technology in order to develop bacteria-repellent surfaces through laser surface nanostructuring.
Funding notice: This study was funded by the European Union's research and innovation program under the FET Open grant agreement No. 862016 (BioCombs4Nanofibers, http://biocombs4nanofibers.eu).
The processing of laser-induced periodic surface structures (LIPSS) represents a simple and robust way for the nanostructuring of solids that allows creating a wide range of surface functionalities featuring applications in optics, tribology, medicine, energy technologies, etc. While the currently available laser and scanner technology already allows surface processing rates at the m2/min level, industrial applications of LIPSS are sometimes hampered by the complex interplay between the nanoscale surface topography and the specific surface chemistry. This typically manifests in difficulties to control the processing of LIPSS and in limitations to ensure the long-term stability of the created surface functions. This presentation aims to identify some unsolved scientific problems related to LIPSS, discusses the pending technological limitations, and sketches the current state of theoretical modelling. Hereby, it is intended to stimulate further research and developments in the field of LIPSS for overcoming these limitations and for supporting the transfer of the LIPSS technology into industry.
Using nanofiber-like cell appendages, secreted proteins and sugars, bacteria can establish initial surface contact followed by irreversible adhesion and the formation of multicellular biofilms. Here, the stabilizing extracellular biofilm matrix together with physiological changes on the single cell level leads to an increased resilience towards harsh environmental conditions, antimicrobials, the host immune response and established cleaning procedures. Persistent microbial adhesion on e.g., medical implants, in water supply networks or food-processing industry is often associated with chronic inflammation, nosocomial and foodborne infections, enhanced biofouling and product contamination. To prevent persistent microbial colonization, antibacterial surface strategies often target the initial steps of biofilm formation and impede adhesion of single cells before a mature biofilm is being formed. While chemical coatings have been widely used, their restricted biocompatibility for eukaryotic cells and attenuated antibacterial-effects due to compound release limit their areas of application and alternative strategies focus on modified surfaces topographies to impede bacterial adhesion. In this work, we used ns-UV laser treatment (wavelength 248 nm and a pulse duration of 20 ns) to generate laser-induced periodic surface structures (LIPSS) with different submicrometric periods ranging from ~210 to ~610 nm on commercial poly(ethylene terephthalate) (PET) foils. Following structurally and chemically analyses, PET samples were subjected to bacterial colonization studies with Escherichia coli TG1, a bacterial test strain with a strong biofilm formation capacity due to the formation of nanofiber-like cell-appendages (pili). Bacterial adhesion tests revealed that E. coli repellence decisively depends on the spatial periods of the LIPSS with the strongest reduction (~91%) in cell adhesion observed for LIPSS periods of 214 nm. Scanning electron microscopy and additional biofilm studies using a pili-deficient E. coli TG1 strain revealed the importance of extracellular appendages in the bacterial repellence observed here, thus, pointing out new antibiotics-free strategies for antibacterial surfaces by impeding nanofiber-mediated bacterial adhesion.
Data for the publication "The role of extracellular polymeric substances of fungal biofilms in mineral attachment and weathering" (https://doi.org/10.1038/s41529-022-00253-1). It includes:
- The Summary of the EPS concentration, EPS sugar components and EPS linkages.
- The Summary of the XPS analysis of freeze-dried biofilm samples of all strains.
- The Summary of the pH, Mg, SI and Fe concentration, biomass and olivine dissolution rate for each time point of all dissolution experiments.
Nonporous corundum powder, known as an abrasive material in the industry, was functionalized covalently with protein binders to isolate and enrich specific proteins from complex matrices. The materials based on corundum were characterized by TEM, ESEM, BET, DLS, and zeta potential measurements. The strong Al-O-P bonds between the corundum surface and amino phosphonic acids are used to introduce functional groups for further conjugations. The common cross-linker glutaraldehyde was compared with a hyperbranched polyglycerol (PG) of around 10 kDa. The latter is oxidized with periodate to generate aldehyde groups that can covalently react with the amines of the surface and the amino groups from the protein via a reductive amination process. The amount of bound protein was quantified via aromatic amino acid analysis (AAAA). This work shows that oxidized polyglycerol can be used as an alternative to glutaraldehyde. With polyglycerol, more of the model protein bovine serum albumin (BSA) could be attached to the surface under the same conditions, and lower nonspecific binding (NSB) was observed. As a proof of concept, IgG was extracted with protein A from crude human plasma. The purity of the product was examined by SDS-PAGE. A binding capacity of 1.8 mg IgG per g of corundum powder was achieved. The advantages of corundum are the very low price, extremely high physical and chemical stability, pressure resistance, favorable binding kinetics, and flexible application.
BAM is currently building up a platform of novel nanoRMs relying on iron oxide nanoparticles of different shape, size and surface chemistry. Iron oxide was chosen as a core material because of its relevance to the material and life sciences.
As a first candidate of this series, we present cubic iron oxide nanoparticles with a nominal edge length of 8 nm. These particles were synthesized by thermal decomposition of iron oleate in high boiling organic solvents adapting well-known literature procedures. After dilution to a concentration suitable for electron microscopy (TEM and SEM) as well as for small-angle X-ray scattering (SAXS) measurements, the candidate nanoRM was bottled and assessed for homogeneity and stability by both methods following the guidelines of ISO 17034 and ISO Guide 35.
The particle sizes obtained by both STEM-in-SEM and TEM are in excellent agreement with a minimum Feret of 8.3 nm ± 0.7 nm. The aspect ratio (AR) of the iron oxide cubes were extracted from the images as the ratio of minimum Feret to Feret resulting in an AR of 1.18 for TEM to 1.25 for SEM. Alternatively, a rectangular bounding box was fitted originating from the minimum Feret and the longest distance through the particle in perpendicular direction. This led to AR values of 1.05 for TEM and 1.12 for SEM, respectively. The results confirm the almost ideal cubic shape.
Antibiotic resistance is a growing global problem which poses a massive threat to human health. Although human activity contributes to the acceleration of the process, bacteria have a self-driven stabilisation mechanism to protect themselves from such and other external threats: biofilm formation. Nonetheless, it is the adhesion of a single bacterial cell to a surface that triggers the formation of such network of biomolecules and microorganisms, as well as its hazardous consequences. The main objective of this work was to quantify the adhesion force of a single E. coli cell on a Ti substrate via the AFM-related single-cell force spectroscopy, with both the cell and the substrate material being of high clinical relevance. A set of 25 x 25 force displacement curves was acquired with a maximum force of 3.2 nN without dwell time, yielding a topography map and an adhesion force map that showed to be correlated. A mean adhesion force of 0.85 ± 0.175 nN was measured and the presence of cell appendages on the bacterial cell wall was verified through individual force-displacement curves. Bacterial viability was assessed after the measurements via live/dead staining.
Nonporous corundum powder was functionalized covalently with protein binders to isolate and enrich specific proteins from complex matrices.The common crosslinker glutaraldehyde was compared with a hyperbranched polyglycerol (PG) of around 10 kDa. The latter was oxidized with periodate to generate aldehyde groups that can covalently react with the amines of the surface and the amino groups from the protein via a reductive amination process. The amount of bound protein was quantified via aromatic amino acid analysis (AAAA). As a proof of concept, IgG was extracted with protein A from crude human plasma. The advantages of corundum include the very low price, extremely high physical and chemical stability, pressure resistance, favorable binding kinetics, convenient handling, and flexible application.
Sehr geehrte Damen und Herren,
liebe Leserinnen und Leser,
bereits im ersten Band der N.i.Ke. Schriftenreihe des Netzwerks zur interdisziplinären Kulturerhaltung hatte ich angeführt, dass bei der Untersuchung von kulturellen Artefakten naturwissenschaftliche Untersuchungsmethoden zunehmend an Bedeutung gewinnen, sie eigentlich unverzichtbar geworden sind.
Ein besonders einprägsames Beispiel dieser fächerübergreifenden Zusammenarbeit zwischen Geisteswissenschaften, Naturwissenschaften und Restaurierungswissenschaften war die Ausstellung Johannes Vermeer. Vom Innehalten, die in diesem Jahr in der Gemäldegalerie Alter Meister in den staatlichen Kunstsammlungen Dresden gezeigt wurde. Eigens für diese Ausstellung wurde das Gemälde Brieflesendes Mädchen am offenen Fenster einer grundlegenden Restaurierung unterzogen. Diese Restaurierung diente jedoch nicht nur der Reparatur des Bildes. Um sich dem ursprünglichen Zustand des Gemäldes zwischen 1657 und 1659 anzunähern, wurden später hinzugefügte Malschichten großflächig abgenommen. Möglich wurde dies durch unterschiedliche, bildgebende materialwissenschaftliche Untersuchungen im Vorfeld, welche die wissenschaftlichen Grundlagen für die Diskussion über den weiteren Umgang mit der Lesenden schufen.
Materialanalytische Verfahren wurden und werden ständig weiterentwickelt und optimiert. Sei es, um aus einer Vielzahl von Einzelmessungen ein Gesamtbild zu erstellen, oder die Größe einer Probenentnahme so zu reduzieren, dass von einer „minimal-invasiven“ oder „quasi nicht-invasiven“ Untersuchung ausgegangen werden kann. Nun feiert die Bundesanstalt für Materialforschung und -prüfung, zusammen mit ihren Vorgängerinstitutionen, den königlichen Versuchsanstalten, in diesem Jahr ihren einhundertfünfzigsten Geburtstag. Sie blickt damit auf eine lange Tradition materialwissenschaftlicher Analysen zurück, an deren Beginn beispielsweise die metallographischen Untersuchungen von Adolf Martens stehen. Derartige Untersuchungen bilden auch heute noch einen wesentlichen Bestandteil archäometallurgischer Forschung. Die Historie bzw. die Weiterentwicklung der Methodik lässt sich hier besonders gut nachzeichnen. Jedoch blicken auch Verfahren zur Charakterisierung weiterer Werkstoffe, wie Glas, Keramik, oder organischer Materialien auf eine lange Geschichte zurück.
Die in diesem Band der N.i.Ke.-Schriftenreihe präsentierten Beiträge dokumentieren einerseits aktuelle Forschungsarbeiten, die erst in diesem Jahr in entsprechenden Fachjournalen publiziert wurden, andererseits liegen einige der Arbeiten bereits 50 Jahre zurück. Sie bekunden damit nicht nur die materialtechnologische und historische Bandbreite der Projekte, sondern offenbaren die Vielfältigkeit kulturhistorischer oder restauratorischer Fragestellungen, zu deren Beantwortung natur- und materialwissenschaftliche Forschung wesentliche Beiträge liefern können.
Ich bedanke mich bei allen Kolleginnen und Kollegen, die zur Erstellung dieser dritten Ausgabe der N.i.Ke. Schriftenreihe des Netzwerks zur interdisziplinären Kulturerhaltung beigetragen haben. Ihre Aufsätze ermöglichen den Blick in die Vielfältigkeit materialwissenschaftlicher Untersuchungen im Bereich Kunst- und Kulturgut. Ich wünsche Ihnen viel Spaß auf dieser kleinen Zeitreise.
Tour de table - BAM
(2021)
ICP-ToF (Flugzeitanalysator, engl. time of flight)-MS ermöglicht den Multielement Fingerabdruck einzelner Zellen (single cell) zu analysieren. Die single cell-ICP-ToF-MS kommt bei dem vorgestellten Poster bei der Analyse von Archaeen, die an mikrobiell beeinflusster Korrosion (engl. microbiologically influenced corrosion, MIC) von Stahl eine Rolle spielen, zum Einsatz. Mittels sc-ICP-ToF-MS wird die mögliche Aufnahme von einzelnen Elementen aus dem jeweiligen Stahl untersucht – die erhaltenen Informationen fließen zukünftig in die Aufklärung zugrunde liegender Mechanismen sowie Entwicklung möglicher Materialschutzkonzepte ein. Die Arbeiten Verknüpfen moderne Methoden der Analytical Sciences mit Materialien.