Controlled deposition of nanoparticles by electrospray for improved analysis by imaging techniques
- Of many experimental techniques for measuring particle sizes and size distributions, electron microscopy (EM) is still considered as the gold standard, especially in the nano range (1–100 nm). Furthermore, high-resolution X-ray spectroscopy (EDX) in conjunction with EM can be applied to individual NPs. Preparation of an EM sample for generic particulate materials is a difficult task. Usually the particles in a suspension are deposited on a support. However, this procedure includes the drying of larger solvent amounts on the substrate itself, and this can affect the spatial distribution of the deposited particles. One possibility to overcome this is the use of an electrospray system, where the suspension of particles is sprayed onto the substrate in charged droplets that are so small that they either dry off on the substrate immediately without affecting the position of particles, or even already during their flight time to the substrate. Additionally, the charging of particlesOf many experimental techniques for measuring particle sizes and size distributions, electron microscopy (EM) is still considered as the gold standard, especially in the nano range (1–100 nm). Furthermore, high-resolution X-ray spectroscopy (EDX) in conjunction with EM can be applied to individual NPs. Preparation of an EM sample for generic particulate materials is a difficult task. Usually the particles in a suspension are deposited on a support. However, this procedure includes the drying of larger solvent amounts on the substrate itself, and this can affect the spatial distribution of the deposited particles. One possibility to overcome this is the use of an electrospray system, where the suspension of particles is sprayed onto the substrate in charged droplets that are so small that they either dry off on the substrate immediately without affecting the position of particles, or even already during their flight time to the substrate. Additionally, the charging of particles minimizes agglomeration and aggregation, maximizing the collection of the EM grids. The prototype of an electrospray deposition system from RAMEM under its trademark IONER (www.ioner.eu) was tested. Electrospray is theoretically described since a long time, but no dedicated commercial instruments are available for the preparation of TEM grids yet, apart from electrostatic deposition of aerosols.2 Several materials have been sprayed onto TEM grids and the resulting particle distributions were evaluated. Operation parameters such as the sample flow-rate, capillary – substrate distance, electric field strength and sampling period length have been optimized. It was found that the particles deposited by electrospray generally show a much more homogeneous spatial distribution on the substrate and a substantial increase of the number of single particles (suited to automatic analysis).…
Autor*innen: | Vasile-Dan HodoroabaORCiD |
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Koautor*innen: | Johannes Mielke, P. Dohányosová, P. Müller, S. López-Vidal |
Dokumenttyp: | Posterpräsentation |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2018 |
Organisationseinheit der BAM: | 6 Materialchemie |
6 Materialchemie / 6.1 Oberflächen- und Dünnschichtanalyse | |
DDC-Klassifikation: | Naturwissenschaften und Mathematik / Chemie / Analytische Chemie |
Freie Schlagwörter: | Electron microscopy; Electrospray deposition; Nanoparticles |
Themenfelder/Aktivitätsfelder der BAM: | Chemie und Prozesstechnik |
Veranstaltung: | RSC-NPL Symposium: Nanoparticle concentration – critical needs and state-of-the-art measurement |
Veranstaltungsort: | London, UK |
Beginndatum der Veranstaltung: | 24.04.2018 |
Enddatum der Veranstaltung: | 25.04.2018 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 27.04.2018 |
Referierte Publikation: | Nein |