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New approaches in low-pressure plasma polymerization for advanced functional materials

ORAL · Invited

Abstract

Low-pressure plasma polymerization is a powerful and environmentally friendly technique for functionalizing advanced materials. Plasma polymer films (PPFs) synthesized from organosilicon monomers exhibit tunable wettability and nanoporosity, which can be precisely controlled by adjusting plasma parameters and reactor design. Advanced characterization techniques - such as Atomic Force Microscopy, Positron Annihilation Spectroscopy, and Neutron Reflectometry - reveal that these films possess a highly interconnected nanoporous network, with well-defined pores below 1 nm and minimal defects above the 1-nanometer scale. These properties make PPFs excellent candidates for next-generation membrane applications: in this talk, I will demonstrate how these coatings can be employed to modulate radical chemistry.

Despite significant progress in plasma-enhanced chemical vapor deposition (PECVD), the mechanisms governing plasma polymer growth on complex 3D substrates remain insufficiently understood. However, such geometries are increasingly important for applications like fiber-based biomaterials and advanced water filtration systems. Over the past few years, my research has focused on elucidating film growth dynamics in 3D architectures, where surface exposure to the plasma environment is inherently non-uniform.

Leveraging the unique properties of nanoporous PPFs, we have developed a novel approach to modulate radical delivery. To our knowledge, we are among the first to use ultra-thin SiOx-like plasma polymer nanolayers to control the generation and release of reactive oxygen species (ROS). These functional coatings are deposited atop amorphous metal oxide catalysts, also fabricated via plasma processes. The porous polymer layer regulates the diffusion of H2O and O2, enabling controlled ROS production at the catalyst surface and targeted release without significant ion leaching or cytotoxic effects. This presentation will highlight how these advanced catalysts can selectively target microbes and emerging contaminants through precise quantitative and qualitative control of ROS delivery.

Publication: 1. Water Decontamination via Reactive Oxygen Species Generated by Silver-Titanium Oxide Plasma Coatings; J. Morini, E. Chabal, D. Hegemann, P. Navascués. In preparation, 2025.<br>2. Engineering nanoscale porosity in SiOx plasma polymer films via ion-induced processes and chemical oxidation; P. Navascués et al. In preparation, 2025.<br>3. Plasma Functionalization Enables Diffusion Control of Reactive Oxygen Species; P. Navascués et al. Under review in Small, 2025. Preprint: https://doi.org/10.48550/arXiv.2411.01219.<br>4. Avoiding dust contamination by near-plasma chemical surface engineering; D. Hegemann, M. Góra, F. Kalemi, P. Navascués,<br>Materials Today Nano, 27, 100503, 2024. https://doi.org/10.1016/j.mtnano.2024.100503.<br>5. Polymerization mechanisms of hexamethyldisiloxane in low-pressure plasmas involving complex geometries; P. Navascués, M. Buchtelová, L. Zajícková, P. Rupper, D. Hegemann, Applied Surface Science, 645, 158824, 2024. https://doi.org/10.1016/j.apsusc.2023.158824.<br>6. Near-Plasma Chemical Surface Engineering; P. Navascués, U. Schütz, B. Hanselmann, D. Hegemann, Nanomaterials 14(2), 195, 2024. https://doi.org/10.3390/nano14020195.

Presenters

  • Paula Navascués

    Empa, Swiss Federal Laboratories for Materials Science and Tecnology

Authors

  • Paula Navascués

    Empa, Swiss Federal Laboratories for Materials Science and Tecnology

  • Julia Morini

    Empa, Swiss Federal Laboratories for Materials Science and Technology

  • Emmanuel Chabal

    Empa, Swiss Federal Laboratories for Materials Science and Technology

  • Flaela Kalemi

    Empa, Swiss Federal Laboratories for Materials Science and Technology

  • Dirk Hegemann

    Empa, Swiss Federal Laboratory for Materials Science and Technology