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Deposition of nanoparticles by electrospray for improved analysis by SEM/TEM and EDX

  • 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 individul 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 individul 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 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. 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).zeige mehrzeige weniger

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Metadaten
Autor*innen:Vasile-Dan HodoroabaORCiD
Koautor*innen:Johannes Mielke, P. Dohányosová, P. Müller, S. López-Vidal
Dokumenttyp:Vortrag
Veröffentlichungsform:Präsentation
Sprache:Englisch
Jahr der Erstveröffentlichung:2017
DDC-Klassifikation:Naturwissenschaften und Mathematik / Chemie / Analytische Chemie
Freie Schlagwörter:Electrospray deposition; Nanoparticles; SEM; TEM; TEM grid
Veranstaltung:17th European Conference on Applications of Surface and Interface Analysis (ECASIA 2017)
Veranstaltungsort:Montpellier, France
Beginndatum der Veranstaltung:24.09.2017
Enddatum der Veranstaltung:29.09.2017
Verfügbarkeit des Dokuments:Datei im Netzwerk der BAM verfügbar ("Closed Access")
Datum der Freischaltung:09.10.2017
Referierte Publikation:Nein
Eingeladener Vortrag:Nein
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