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Electrohydrodynamic atomization (EHDA) is a liquid spraying technique that can be used to produce particles
much smaller than the nozzle, applying a high electric field. Specifically, in the NANOMANU project, a dualnozzle EHDA system was used in "cone-jet" mode to produce metal-doped polymer nanoparticles with a
narrow size distribution. To produce these particles, multiple parameters had to be considered, such as a) the
properties of the internal and external liquids that affect the cone-jet stability, b) the immiscibility/miscibility that
determine the production of core-particle shell (P1) and embedded particles with a metal (P2), respectively
and c) tunable parameters such as flow and voltage.
All these parameters were studied during the project, leading to the production of both P1 and P2 particles of
different polymer types, using mainly indium and titanium as metals. To allow the use of all the analytical tools
required, the produced particles have been collected both in dry and liquid media. Specifically, when collected
in liquid media, it was also necessary to study the conditions to obtain a stable particle dispersion. The particles
were then analyzed with different analytical techniques such as SEM-EDX, SP-ICP-MS, DLS. These
techniques have shown the production of particles of different sizes and shapes, during the whole project. The
final results showed that, using the coaxial EHDA, it was possible to produce particles monodispersed,
spherical and in a size range of 1-2 micrometers, containing the metal inside. However, the position of the
metal has not yet been confirmed by the TEM analysis.
The Water Framework Directive imposes challenges regarding the environmental risk of plastic pollution. The quantification, qualification, monitoring, and risk assessment of nanoplastics and small microplastic (<20 µm) is crucial. Environmental nano- and micro-plastics (NMPs) are highly diverse, accounting for this diversity poses a big challenge in developing a comprehensive understanding of NMPs detection, quantification, fate, and risks. Two major issues currently limit progress within this field: (a) validation and broadening the current analytical tools (b) uncertainty with respect to NMPs occurrence and behaviour at small scales (< 20 micron). Tracking NMPs in environmental systems is currently limited to micron size plastics due to the size detection limit of the available analytical techniques. There are currently no methods that can detect nanoplastics in real environmental systems. A major bottleneck is the incompatibility between commercially available NMPs and those generated from plastic fragments degradation in the environment. To track nanoplastics in environmental and biological systems, some research groups synthesized metal-doped nanoplastics, often limited to one polymer type and using high concentrations of surfactants, rendering these synthesized nanoplastics to not be representative of nanoplatics found in real environment. NanoManu proposes using Electrohydrodynamic Atomization to generate metal doped NMPs of different polymers types, sizes, and shapes, which will be representative of the real environmental nanoplastics. The synthesized nanoplastics will be used as model particles in environmental studies. The synthesized nanoplastics will be characterized and tested using different analytical methods, e.g., SEM-EDX, TEX, GCpyrMS, FFF, µFTIR and SP-ICP-MS. NanoManu is a first and critical step towards generating a comprehensive state-of-the-art analytical and environmental knowledge on the environmental fate and risks of nanoplastics. This knowledge impacts current risk assessment tools, efficient interventions to limit emissions and adequate regulations related to NMPs.