Anmelden

Open Access

  • Startseite
  • Suchen
  • Browsen
  • Veröffentlichen
  • Hilfe

Filtern

Autor

  • Becker, Roland (4)
  • Elert, Anna Maria (2)
  • Falkenhagen, Jana (2)
  • Braun, Ulrike (1)
  • Dümichen, Erik (1)
  • Eisentraut, Paul (1)
  • Hoffmann, Katrin (1)
  • Reinsch, Stefan (1)
  • Resch-Genger, Ute (1)
  • Scholz, Philipp (1)
+ weitere

Erscheinungsjahr

  • 2019 (1)
  • 2018 (2)
  • 2017 (1)

Dokumenttyp

  • Zeitschriftenartikel (2)
  • Vortrag (1)
  • Posterpräsentation (1)

Sprache

  • Englisch (3)
  • Deutsch (1)

Referierte Publikation

  • nein (3)
  • ja (1)

Schlagworte

  • Referenzmaterialien (2)
  • Schwebstoffe (2)
  • Analysis and identification (1)
  • Artificial weathering (1)
  • Crosslinking (1)
  • Degradation (1)
  • FTIR imaging (1)
  • Methodenvergleich (1)
  • Microplastics (1)
  • Mikroplastik (1)
+ weitere

Organisationseinheit der BAM

  • 6.6 Nano-Tribologie und Nanostrukturierung von Oberflächen (4) (entfernen)

4 Treffer

  • 1 bis 4
  • CSV
  • RIS
  • 10
  • 20
  • 50
  • 100

Sortieren nach

  • Jahr
  • Jahr
  • Titel
  • Titel
  • Autor
  • Autor
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.
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.
Querschnittsthema Referenzmaterialien: Planung Ringversuche (2018)
Becker, Roland
Nach einer Erläuterung der international üblichen Definitionen von Referenzmaterialien und Matrix-Referenzmaterialien erfolgt eine Zusammenfassung der spezifischen Anforderungen bei Herstellung und Charakterisierung. Weiterhin werden die unterschiedlichen Anforderungen an die Durchführung von Ringversuchen im Sinne eines Methodenvergleiches, einer Eignungsprüfung von Laboratorien und der Zertifizierung von Matrix-Referenzmaterialien gegenübergestellt. Für den aktuell geplanten ersten Ringversuch zur Quantifizierung von Mikroplastik in Schwebstoffen mittels thermischer Verfahren werden die konkreten technischen Bedingungen zur Herstellung entsprechender Referenzmaterialien einschließlich der Homogenitätsprüfung ihrer Mikroplastikgehalte dargestellt. Die Besonderheiten des Ringversuches vor dem Hintergrund einer Normung der eingesetzten Verfahren werden diskutiert.
Reference materials for microplastics in environmental matrices (2018)
Becker, Roland
The pollution of marine, limnic and terrestrial environments with plastic waste and the potential impact especially on biota and humans has received increasing attention in recent years. Special focus is on particles smaller than 5 mm, the so-called microplastics. Consequently, possible regulations of emission and remediation efforts require sound information on the occurrence and fate of microplastics in the respective environmental compartments. Microplastics (MP) differ from classical organic pollutants in biota or the environment in that they do not consist of clearly defined low-molecular weight compounds but of polymer particulates with varying sizes and chemical compositions. This leads to specific challenges regarding the analytical techniques to be employed for their identification and quantification. Microplastics are defined as polymer particle in the size range between 1 µm and 5 mm and cover a wide range of polymers such as polyethylene, polypropylene, polystyrene and polyethylene terephthalate in variable geometric shapes. Properties relevant for environmental microplastics are polymer type, particle form and size distribution, surface morphology (aging status) and total mass fraction contained in a given sample. Polymer identification and particle size estimation using optical methods (IR and Raman spectroscopy) are time consuming and complicated by surface characteristics as a result of weathering, soiling, and microbial colonisation. Total mass fractions of MP in environmental samples can be determined by thermo-analytical methods. There are currently no standardised methods for sampling, sampling preparation, or detection of MP in environmental samples. So far, qualitative and quantitative investigations are done by research institutes and have not reached the routine laboratory community. The near future will see harmonisation efforts of MP mass fraction determination in environmental matrices by thermo-analytical procedures. The immediate need for reference materials during method development and comparison is outlined with regard to relevant matrix/polymer compositions, existing regulations and currently achievable detection limits. Examples for solid environmental matrix reference materials are discussed regarding the challenges encountered with matrices and polymer types as well as homogeneity testing and property value characterisation.
  • 1 bis 4

OPUS4 Logo

  • Kontakt
  • Impressum
  • Sitelinks