6.1 Oberflächen- und Dünnschichtanalyse
Filtern
Dokumenttyp
- Vortrag (221)
- Zeitschriftenartikel (196)
- Posterpräsentation (97)
- Forschungsdatensatz (27)
- Sonstiges (16)
- Beitrag zu einem Sammelband (10)
- Forschungsbericht (8)
- Beitrag zu einem Tagungsband (7)
- Handbuch (4)
- Sammelband (Herausgeberschaft für den kompletten Band) (2)
Sprache
- Englisch (593) (entfernen)
Schlagworte
- Nanoparticles (129)
- XPS (91)
- Electron microscopy (58)
- SEM (50)
- VAMAS (40)
- X-ray photoelectron spectroscopy (32)
- HAXPES (31)
- Particle size distribution (30)
- ToF-SIMS (29)
- NAP-XPS (23)
Organisationseinheit der BAM
- 6 Materialchemie (593)
- 6.1 Oberflächen- und Dünnschichtanalyse (593)
- 1 Analytische Chemie; Referenzmaterialien (52)
- 6.6 Physik und chemische Analytik der Polymere (46)
- 4 Material und Umwelt (32)
- 1.2 Biophotonik (27)
- 5 Werkstofftechnik (27)
- 6.3 Strukturanalytik (24)
- 6.7 Materialsynthese und Design (23)
- 6.2 Material- und Oberflächentechnologien (22)
Paper des Monats
- ja (7)
Since there is a lack of knowledge about the effects of nanomaterials on human health and the environment, and in order to get safe- and sustainable-by-design nanomaterials, it is necessary to find an easy way to assess their properties, without having to perform time-consuming experiments each time. In the European project NanoSolveIT, the behavior of nanoparticles is to be derived from a nanomaterial fingerprint database with standardized physico-chemical properties of nanomaterials. The key element for these grouping and reading across approaches is the collection of standardized information about nanomaterials in combination with modelling and simulations. As parameters the particle size, particle shape, chemical composition and surface chemistry are discussed here.
Measurements of the shape and size were performed using scanning electron microscopy (SEM). For the chemical composition energy dispersive X-ray spectroscopy (EDS) and for the surface chemistry X-ray photoelectron spectroscopy (XPS) were used. As an additional method hard X-ray photoelectron spectroscopy (HAXPES) with a higher information depth than XPS was used, thus we were able to include information not only from the top surface, but also from deeper regions of about 30 nm. Therefore, this method is complementary to EDS.
All these methods have been correlatively used to study nanoparticles of different chemical composition that have been treated differently by sterilization. Such a sterilization step is common, before testing for toxicity. To date, the sterilization step has not been considered in establishing the structure-activity relationship of the nanomaterial.
The effects of sterilization are discussed on exemplary samples. The results demonstrate the influence of sterilization on all investigated properties, indicating a restructuring of the nanoparticles. This implies that samples that have been sterilized after synthesis, may show different toxicity from those used in applications without a sterilization step.
Acknowledgement: This research is part of the project “NanoSolveIT”, which has received funding from European Union Horizon 2020 Programme (H2020) under grant agreement no 814572. (https://nanosolveit.eu/)
Since its isolation, graphene has received growing attention from academia and industry due to its unique properties. Promising opportunities for applications are discussed in different field like electronics and optoelectronics, detection, and sensing devices, biosystems or chemical and environmental corrosion inhibition. Here, functionalization with elements like oxygen, nitrogen or fluorine can broaden the application, for example in composite materials. However, lack of generally accepted operation procedures hinders the commercialization, the so-called “what is my material” barrier. Therefore, first efforts were done to develop common, reliable, and reproducible ways to characterize the morphological and chemical properties of the industrially produced material.
In this contribution, our efforts in the development of reliable chemical characterizations protocols for functionalized graphene are presented. An ISO standard for the chemical characterization of graphene-related (GRM) is under development with X-ray photoelectron spectroscopy (XPS) having a prominent role. With its information depth of around 10 nm, which is the similar length scale as the thickness of particles of 2D materials consisting of a few monolayers, XPS seems to be highly suitable for the quantitative analysis of (functionalized) GRM. Thereby, different sample preparation methods like pressing the powders onto adhesive tapes, into recesses, or into solid pellets result in inconsistencies in the quantification. Furthermore, different morphologies like stacks of graphene layers (left figure) or irregular particles (right figure) lead to different analysis results for the chemical composition.
For the validation of the quantification with XPS and the further development of standards an international interlaboratory comparison was initiated under the head of the “Versailles Project on Advanced Materials and Standards” (VAMAS). First results are reported showing the suitability of the protocols. Finally, the XPS results are compared with the elemental composition results obtained after quantification with energy-dispersive X-ray spectroscopy (EDS) as a fast analytical method which is usually combined with electron microscopy.