Plasma Processes in Contact with Liquids

• Oxidizing atmospheres (air, O₂, water vapour): generation of •OH radicals, O₃ and H₂O₂ for degradation, disinfection, oxidation and surface functionalization.
• Reducing atmospheres (H₂, Ar/H₂): hydrogenation, reduction of metal cations and production of low-oxidation-state metallic particles.
• Inert gases and reduced pressure (Ar, N₂, partial vacuum): adjustable energy density, residence time and gas temperature, enabling more selective chemistry on sensitive substrates.

Our Experience

GREENFRIX

A reactor designed, built and operated in-house: reduced-pressure hydrogen discharge with rotating electrodes immersed in oil and controlled renewal of the liquid film.

Vegetable oils were transformed through radical polymerisation, enabling viscosity control from 40 to more than 2,000 mPa·s (GPC, rheology). Key parameters such as power density, pressure and fresh reactant addition were mastered to produce tailor-made products while reducing processing time by a factor of 10 compared to the historical process.

LaStrADA (CORNET, with Fraunhofer IFAM and DFO)

An Ion Jet microwave torch coupled with the spraying of a metal salt solution enabled the precipitation of Cu, Ni or Ag nanoparticles within a liquid film deposited on laser-structured polymers. This was followed by electroless metallisation without the use of Pd or Cr(VI).

Target Applications:

Plasma-induced precipitation and particle synthesis (PILC)
Our plasma-induced precipitation and particle synthesis process (PILC) uses the reactive species generated at the plasma-liquid interface — solvated electrons, radicals, reducing species — to directly reduce metal cations dissolved in an aqueous solution. This pathway enables the recovery of dissolved metals from industrial effluents, spent surface-treatment baths or waste electrical and electronic equipment (WEEE), producing calibrated metal nanoparticles and oxides (copper, nickel, silver, noble metals) directly in the liquid, up to in-situ deposition on a substrate, without conventional chemical reducing agents. This technology is aimed primarily at metal recycling and the circular economy, heterogeneous catalysis, electronics and microelectronics, and functional metallization of polymers and textiles.
Markets: metal recycling & circular economy, catalysis, electronics/microelectronics, metallization and surface treatment.

Plasma-based water and wastewater treatment
Contact between an atmospheric plasma and an aqueous phase generates powerful oxidizing species in situ — hydroxyl radicals, ozone, hydrogen peroxide — capable of degrading persistent organic pollutants, including PFAS ("forever chemicals"), through advanced oxidation, while also achieving decolorization and reduction of the organic load in industrial and municipal wastewater. With no added chemical reagents and no chlorination by-products, this wastewater treatment and effluent decontamination process serves the chemical, textile, paper and food industries, drinking-water operators facing PFAS remediation challenges, and contaminated sites and soils requiring advanced depollution.
Markets: industrial and municipal wastewater treatment, PFAS remediation, chemical/textile/paper industries, drinking-water management.
Plasma disinfection of aqueous solutions
Reactive oxygen and nitrogen species generated by plasma in contact with liquid efficiently reduce the microbial load of aqueous solutions, offering an alternative to chemical disinfection with chlorine or biocides, with no toxic residues or by-products. This chlorine-free disinfection approach is of particular interest to the biomedical sector (medical devices, water for medical use), the food industry (process water, packaging lines), and more broadly any water treatment application where microbial load must be controlled without altering the liquid's chemical composition.
Markets: biomedical & medical devices, food industry, chlorine-free water treatment.

Plasma chemistry of organic liquids
Applied to organic liquids — vegetable oils, hydrocarbons, petroleum-derived compounds — plasma chemistry enables controlled functionalization and oxidation of these feedstocks, opening valorization pathways toward higher-value oxygenated compounds. At Materia Nova, this expertise has, for example, allowed the viscosity of polymerized vegetable oils to be tuned from 40 to over 2000 mPa·s, with a tenfold reduction in process time. This technology serves green chemistry and biorefineries, the petrochemical and lubricants industry, and the formulation of bio-based resins and oxygenated intermediates.
Markets: green chemistry & biorefineries, petrochemicals & lubricants, bio-based resins and intermediates.

Interface properties and plasma-aerosol
Plasma treatment of liquid interfaces and in-flight microdroplets enables oil hydrophilization, thin-film deposition and encapsulation of active ingredients, with precise control over surface properties and no added solvents. These aerosol and microdroplet treatment processes find applications in cosmetics and formulation (active-ingredient encapsulation, emulsions), pharmaceuticals (drug delivery, microencapsulation), and coatings and functional materials requiring precisely controlled plasma-based thin-film deposition.
Markets: cosmetics & formulation, pharmaceuticals, coatings & functional materials.