High performance nanostructured coatings using ionic liquids based on choline chloride - NANOCOATIL

NANOCOATIL aimed to develop novel strategies to produce different nanostructured coatings involving choline chloride based ionic liquids (also known as Deep Eutectic Solvents – DESs), possessing better corrosion performance and enhanced growth rate.

The main advantage of the development and promotion of the use of these new electrochemical media referred not only to the accumulation of new scientific information but also allows the minimization of production costs, of industrial waste quantities, with positive effects on environment and health. The proposal addressed new processing routes and new solutions to develop nanostructured coatings with tailored properties through optimization either cathodic or anodic reaction.

Within the project NANOCOATIL, corrosion resistant Ni-Mo (5-45 wt.% Mo) and Co-Mo (5-65 wt.% Mo) alloys have been produced by electrodeposition involving novel choline chloride – urea - citric acid ternary mixtures, as well as Co-multiwalled carbon nanotubes (Co-MWCNT) composites. Moreover, anodic oxides as nanopowders or ordered nanoporous layers with an enhanced growth rate have been successfully developed onto valve metals (i.e. Al, Ti) using new DES formulations.

Through a careful selection of IL based electrolyte composition and operating conditions various nano-morphologies could be obtained, suitable for different final applications.

During the project, several goals could be achieved:

• Development of various ionic liquid eutectic mixtures formulations suitable for applications in metals and alloys electrodeposition and anodic oxidation of valve metals;
• Successful development of novel electrochemical procedures to deposit nanostructured Ni-Mo and Co-Mo alloy coatings with enhanced corrosion performance. Corrosion current densities in the range of few up to tens of microampers per square centimeter were determined after long-term immersion in 0.5M NaCl aggresive environment;
• Successful development of novel electrochemical procedures to deposit Co-MWCNT composite coatings with enhanced corrosion performance. The involved electrolytic medium facilitated the formation of a stable and homogeneous dispersion of MWCNTs that allowed the incorporation of MWCNTs in the Co matrix. The superior corrosion characteristics of the Co-MWCNT composite may be associated with the presence of the MWCNTs that may hinder the diffusion of aggressive Cl^- ions;
• Successful development of novel Al anodization routes involving chloride free DES based electrolytes, allowing the growth of ordered nanoporous structures having pore diameters between 50 – 80 nm and interpore distances in the range of 160-200 nm, at anodization rates of about 0.2-0.4 µm/min. and anodic efficiencies between 65-87%;
• Design and construction of a small scale laboratory prototype to validate the elaborated technologies.

In addition, the partners have published 7 papers in peer-reviewed journals and delivered more than 10 presentations (oral and poster) in international conferences. More details about the obtained results originated from this work can be found in our publications and on the project website: https://cssnt-upb.ro/pro/nanocoatil/

We would like to emphasize the papers:

Investigation of Ni-Mo and Co-Mo alloys electrodeposition involving choline chloride based ionic liquids, Stefania Costovici , Adrian Manea, Teodor Visan, Liana Anicai, Electrochimica Acta, 207 (2016) 97-111.

(The paper has been selected by the Canadian Advances in Engineering - https://advanceseng.com/chemical-engineering/page/12/, as a key scientific article contributing to science and engineering research excellence

Electrodeposition of Co and Co composites with carbon nanotubes using choline chloride-based ionic liquids, N.M. Pereira, O. Brincoveanu, A.G. Pantazi, C.M. Pereira, J.P. Araujo, A.F. Silva, M. Enachescu, L. Anicai, Surface & Coatings Technology 324 (2017) 451–462

Project Details