Substrate geometry modulates self-assembly and collection of plasma polymerized nanoparticles

Miguel Santos,Richard Tan,Steven G Wise,Bryce Reeves,Praveesuda Michael,Marcela M M Bilek

doi:10.1038/s42005-019-0153-5

Miguel Santos, Richard Tan + Show 4 more

Open Access

https://doi.org/10.1038/s42005-019-0153-5

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Abstract

Plasma polymerized nanoparticles (PPN) formed in plasma reactors have been considered undesirable in technological applications. More recently however, PPN were proposed as a new class of multifunctional nanocarriers for drug delivery. Therefore, synthesis of PPN requires cost-effective collection strategies that maximize yield and improve reproducibility. This work shows that the collection of PPN in dusty plasmas is modulated by modifying the geometry of substrates from planar to well-shaped collectors. The electric field profile around the wells acts as an electrostatic lens, concentrating nanoparticles and significantly bolstering process yield. The aggregation of PPN is governed by a balance between plasma expansion throughout the wells, inter-particle repulsion, particle size and density. PPN are readily dispersed in aqueous solution yielding monodisperse populations. The use of a disposable well-shape collector provides a cost-effective nanoparticle collection approach that can be adopted in a wide range of plasma polymerization configurations without the need for reactor re-design.

Highlights

Plasma polymerized nanoparticles (PPN) formed in plasma reactors have been considered undesirable in technological applications
These findings propose PPN as a new class of cost-effective nanoparticles for use in a wide range of applications in nanomedicine
This work shows that the assembly and collection of PPN in dusty plasmas can be passively modulated by the geometry of the substrate

Summary

Introduction

Plasma polymerized nanoparticles (PPN) formed in plasma reactors have been considered undesirable in technological applications. Most collection strategies were not developed envisaging the use of plasma dust for nanomedicine and are usually characterized by low nanoparticle yield, size polydispersity or irreversible aggregation These approaches are mostly efficient to remove plasma dust contaminants, they would require specialized equipment (power supplies, vacuum feedthroughs, etc.) that entail modification of pre-existing plasma chambers or otherwise increase the cost and design complexity in the build of new reactors. The nanoparticle collection method reported here allows a non-invasive, highly customizable, and efficient collection of PPN, enabling the use of pre-existing PP systems currently used for coating deposition without the need for external manipulation and reactor re-design. PPN can be dispersed in aqueous solution directly in the wells and for use as nanocarriers without the requirement for further purification steps

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