Modern technologies in the production of functional nanomaterials, widely used for electronics, health-care applications and fertilizer production, are often based on the synthesis of nanomaterial in a powder form, not in suspension or colloids [1, 2]. In some cases, preparation of stable suspension of nanomaterials from nanopowders is restricted. Thus, advanced analytical methods which allow size-fractionated and chemical characterization of powder nanomaterials are highly required that is still challenging. Hence, we report several case studies how single particle microwave plasma optical emission spectrometry (SP-MWP-OES) allowed us to solve this problem.

SP-MWP-OES is a real-time fast detection technique of nanoparticles at ms-time resolution for characterizing powder nanomaterials, providing information about their size, dispersity and agglomeration. Due to the use of simultaneous multi-element specific detection, the SP-MWP-OES can significantly contribute to the characterization of complex nanomaterials including both structural information and their chemical composition on the level of individual particles [3].

We demonstrate the feasibility of SP-MWP-OES for determining size distribution and chemical composition for selected nanopowders. Specifically, we present that this unique technique has been exploited to determine size distribution of nanomaterials of different size, enabling the calibration of the detection system for sizing NPs, and to examine elemental composition of mesoporous SeNPs synthesized using Zn template. SP-MWP-OES enables both identification of organic compounds present on the NPs surface and examination of the molecular interaction between nanoparticles and other species, including the core-shell type nanomaterials. Moreover, we describe fundamental characteristics of axially viewed six-phase rotating field MWP plasma source to examine the plasma response on single particle event affecting plasma robustness. Collectively, presented results described how the use of SP-MWP-OES allowed obtaining more reliable nanopowder characterization.

References

[1] N. H. Ramli et al., Microchemical Journal, 2024, 200, 110280.

[2] A. M. Khalifa et al., BMC Plant Biology, 2024, 24, 607.

[3] M. Borowska et al., Analytica Chimica Acta, 2019, 1089, 25-31.

Research was funded by the Warsaw University of Technology within the Excellence Initiative: Research University (IDUB) programme.