Anmelden

Open Access

  • Startseite
  • Suchen
  • Browsen
  • Veröffentlichen
  • Hilfe

Filtern

Autor

  • Elert, Anna Maria (4)
  • Wachtendorf, Volker (3)
  • Weidner, Steffen (3)
  • Becker, Roland (2)
  • Falkenhagen, Jana (2)
  • Braun, Ulrike (1)
  • Dümichen, Erik (1)
  • Eisentraut, Paul (1)
  • Elert, Anna-Maria (1)
  • Geburtig, Anja (1)
+ weitere

Erscheinungsjahr

  • 2019 (1)
  • 2018 (1)
  • 2017 (3)

Dokumenttyp

  • Zeitschriftenartikel (3)
  • Beitrag zu einem Tagungsband (1)
  • Vortrag (1)

Sprache

  • Englisch (4)
  • Deutsch (1)

Referierte Publikation

  • nein (3)
  • ja (2)

Schlagworte

  • Microplastics (2)
  • TED-GC-MS (2)
  • TPU (2)
  • Analysis and identification (1)
  • Artificial weathering (1)
  • Bewitterung (1)
  • Crosslinking (1)
  • Degradation (1)
  • FTIR imaging (1)
  • Feuchte (1)
+ weitere

Organisationseinheit der BAM

  • 1 Analytische Chemie; Referenzmaterialien (5) (entfernen)

5 Treffer

  • 1 bis 5
  • CSV
  • RIS
  • 10
  • 20
  • 50
  • 100

Sortieren nach

  • Jahr
  • Jahr
  • Titel
  • Titel
  • Autor
  • Autor
Challenges in Microplastics identification is one Detection method enough? (2017)
Elert, Anna Maria
Long-term accumulation and fragmentation of plastic waste in ecosystems is currently a global subject of scientific and social concern. The combination of mechanical abrasion with degradation by UV radiation, and oxidation leads to the formation of small plastic particles (size less than 5 mm) which are not only distributed in oceanic and costal water, but also in sediments and terrestrial compartment. Since the contamination of the environment with plastic particles became emerging issue, an increasing trend towards investigating and controlling the MP pollution of the environment can be observed worldwide. Nonetheless, the reliable methodology that would facilitate and automate the monitoring of MP is still missing. Aiming at the selection of practical and standardized methods we present here a critical comparison of two vibrational spectroscopies, Raman and Fourier transform infrared (FTIR) spectroscopy, and two extraction methods: thermal desorption gas chromatography mass spectrometry (TED-GC-MS) and liquid extraction with subsequent size exclusion chromatography (SEC) using a soil (reference material) with known contents of PE, PP, PS and PET. The results are compared in terms of the measurements time, technique handling, detection limits and requirement for sample preparation. The comparison of Raman and FTIR spectra provides broader understanding of the polymeric origin of the analysed particles. Furthermore, at the level of individual particle, Raman imaging yields additional information on the stage of the polymer degradation and contamination on the surface. On the other hand, by applying the thermal and liquid extraction methods the fast and quantitative analysis of MP content is possible. Therefore, to establish reliable, standardized detection methods a combination of several parallel approaches should be considered.
Comparison of different methods for MP detection: What can we learn from them, and why asking the right question before measurments matters? (2017)
Elert, Anna Maria ; Becker, Roland ; Dümichen, Erik ; Eisentraut, Paul ; Falkenhagen, Jana ; Sturm, Heinz ; Braun, Ulrike
In recent years, an increasing trend towards investigating and monitoring the contamination of the environment by microplastics (MP) (plastic pieces < 5 mm) has been observed worldwide. Nonetheless, a reliable methodology that would facilitate and automate the monitoring of MP is still lacking. With the goal of selecting practical and standardized methods, and considering the challenges in microplastics detection, we present here a critical evaluation of two vibrational spectroscopies, Raman and Fourier transform infrared (FTIR) spectroscopy, and two extraction methods: thermal extraction desorption gas chromatography mass spectrometry (TED-GC-MS) and liquid extraction with subsequent size exclusion chromatography (SEC) using a soil with known contents of PE, PP, PS and PET as reference material. The obtained results were compared in terms of measurement time, technique handling, detection limits and requirements for sample preparation. The results showed that in designing and selecting the right methodology, the scientific question that determines what needs to be understood is significant, and should be considered carefully prior to analysis. Depending on whether the object of interest is quantification of the MP particles in the sample, or merely a quick estimate of sample contamination with plastics, the appropriate method must be selected. To obtain overall information about MP in environmental samples, the combination of several parallel approaches should be considered.
Analytical toolset to characterize polyurethanes after exposure to artificial weathering under systematically varied moisture conditions (2019)
Scholz, Philipp ; Wachtendorf, Volker ; Elert, Anna Maria ; Falkenhagen, Jana ; Becker, Roland ; Hoffmann, Katrin ; Resch-Genger, Ute ; Tschiche, Harald ; Reinsch, Stefan ; Weidner, Steffen
Polyether and -ester urethanes (PU) were exposed to artificial weathering at 40 °C and artificial UV radiation in a weathering chamber. In 3 parallel exposures, humidity was varied between dry, humid, and wet conditions. Material alteration was investigated by various analytical techniques like size exclusion chromatography (SEC), liquid chromatography-infrared spectroscopy (LC-FTIR), thermal-desorption gas chromatography-mass spectrometry (TD-GC-MS), fluorescence mapping and dynamic mechanical analysis (DMA). Our results show that depending on the weathering conditions, different degradation effects can be observed. By means of SEC an initial strong decrease of the molar masses and a broadening of the mass distributions was found. After a material dependent time span this was followed by a plateau where molar mass changes were less significant. A minor moisture-dependent degradation effect was only found for polyester PU. Fluorescence measurements on two materials revealed an increase in the luminescence intensity upon weathering process reaching a saturation level after about 500 h. The changes in the optical properties observed after different exposure conditions and times were very similar. The TD-GC-MS data showed the fate of the stabilizers and antioxidant in the course of weathering. LC-FTIR measurements revealed a change in peak intensities and the ratio of urethane and carbonyl bands.
Effects of UV radiation on the friction behavior of thermoplastic polyurethanes (2018)
Theiler, Geraldine ; Wachtendorf, Volker ; Elert, Anna Maria ; Weidner, Steffen
The effects of weathering exposure on unfilled and filled thermoplastic polyurethanes (TPU) materials are described as performed under different humidity conditions. For this purpose, a weathering device was used with UV-A 340 nm lamps at a constant temperature of 40 °C. The effects of environmental (UV and humidity condition) degradation on the frictional properties of TPU materials are presented along with surface analyses to characterize the chemistry of the degradative process. Photooxidative degradation of unfilled polymer leads to deterioration of physical and mechanical properties, which affects its tribological behavior significantly. Due to crosslinking, the stiffness of the material increases, reducing drastically the friction coefficient of unfilled TPUs. The frictional behavior of glass fiber reinforced TPU is less affected by radiation.
Einfluss von Feuchte und Nässe auf die Witterungs-induzierte Alterung am Beispiel eines Polyurethans (2017)
Wachtendorf, Volker ; Geburtig, Anja ; Elert, Anna-Maria ; Weidner, Steffen
In diesem Beitrag soll der relative Einfluss des Wassers als Feuchte und Nässe unter den Beanspruchungsfaktoren untersucht werden. Die Unterscheidung von Luftfeuchte und Nässe bezüglich ihrer Wirkung ist dabei notwendig, weil die stehende Nässe zusätzliche Extraktionswirkung besitzt und auch die verfügbare Sauerstoffmenge beeinflusst. Dazu wurde ein Polymer, das im Rahmen des BAM-internen Projektes PolyComp untersucht wird, künstlich bewittert. Hierzu wurde ein Fluoreszenzlampengerät mit UV-A 340 nm Leuchtstoffröhren verwendet, in dessen Probenraum durch zusätzliche Kammern die gleichzeitige Bewitterung unter drei unterschiedlichen Feuchte-Varianten realisiert wurde (bei konstanter Temperatur): • UV und trocken • UV und hohe Luftfeuchte • UV und stehende Nässe Das gleichzeitige Einwirken der einzelnen Einflussfaktoren kann dabei konkurrierende oder aufeinander folgende chemische Reaktionen und physikalische Prozesse und somit ein anderes Ergebnis bewirken, als wenn sie isoliert nacheinander auf eine Probe eingewirkt hätten. Über die erwähnten Varianten hinaus kann auch noch der spezifische Einfluss der UV-Strahlung mit untersucht werden, weil die Proben im Bereich ihrer Befestigung verdeckt sind. Die Methodik und erste Ergebnisse dieser Untersuchung werden präsentiert.
  • 1 bis 5

OPUS4 Logo

  • Kontakt
  • Impressum
  • Sitelinks