Projects / Programmes source: ARIS

Multifunctional Nanostructured Films for Artificial Implants - Corrosion and Tribo-corrosion Processes

Research activity

Code Science Field Subfield
2.02.06  Engineering sciences and technologies  Chemical engineering  Biochemical engineering 

Code Science Field
P352  Natural sciences and mathematics  Surface and boundary layery chemistry 

Code Science Field
2.05  Engineering and Technology  Materials engineering 
multifunctional coatings, antibacterial effect, wear resistance, corrosion, tribocorrosion, biomaterials
Evaluation (rules)
source: COBISS
Researchers (12)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  14334  PhD Tonica Bončina  Materials science and technology  Researcher  2011 - 2014 
2.  18271  PhD Miha Čekada  Materials science and technology  Researcher  2011 - 2014 
3.  18635  Tatjana Filipič    Technical associate  2011 - 2014 
4.  10842  PhD Matjaž Godec  Materials science and technology  Researcher  2011 - 2014 
5.  12616  PhD Darinka Kek Merl  Materials science and technology  Head  2011 - 2014 
6.  18475  PhD Aleksandra Kocijan  Materials science and technology  Researcher  2011 - 2014 
7.  22315  PhD Tadeja Kosec  Chemistry  Researcher  2011 - 2014 
8.  15703  PhD Janez Kovač  Electronic components and technologies  Researcher  2011 - 2014 
9.  15603  Andrej Mohar    Technical associate  2011 - 2014 
10.  28561  PhD Jože Moškon  Materials science and technology  Researcher  2011 - 2014 
11.  26463  PhD Matjaž Panjan  Electronic components and technologies  Researcher  2011 - 2014 
12.  09090  PhD Peter Panjan  Materials science and technology  Researcher  2011 - 2014 
Organisations (5)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0104  National Institute of Chemistry  Ljubljana  5051592000  10 
2.  0106  Jožef Stefan Institute  Ljubljana  5051606000  18 
3.  0206  Institute of Metals and Technology  Ljubljana  5051622000 
4.  0795  University ob Maribor, Faculty of mechanical engineering  Maribor  5089638010 
5.  1502  Slovenian National Building and Civil Engineering Institute  Ljubljana  5866324000 
Abstract The proposed project focuses on new, antibacterial thin films, which will be deposited on metals and alloys which are used, or are potentially interesting, for artificial implants in the human body. We will develop the nitride- and carbon- based coatings with the addition of silver or copper components. Therefore, in addition of good wear, corrosion and biocompatible properties, such coatings will exhibit also an antibacterial effect.   For the preparation of nanostructured multifunctional layers, the physical methods of deposition from the vapor phase - PVD (Physical Vapor Deposition) will be used. The basis of the new PVD coatings will be nitrides of transition metals such as TiN, CrN or TaN. These are ceramic materials, which have covalent bonds, that are highly orientated. Therefore, such materials are very hard, brittle, chemically inert, and have a high melting point. By varying the deposition parameters, such as plasma density, substrate temperature and coating regime (magnetron, pulse) we will change their structure and properties.   By introducing a third component (silver or copper) into the coating, the composition, structure and properties will be modified. Silver and copper are insoluble in (Ti,Cr,Ta??)N, and their nitride is unstable. Thus, we will prepare the nano-composite coatings with a complex structure (Figure 1-attachment), alternating between hard and soft crystal phases, metal and non-metal phases. Hard phase is responsible for high wear resistance at high loads, while soft phase reduces friction coefficient and hardness.   Due to intrinsic antimicrobial properties of silver and copper, nano-composite coatings will exhibit additional properties, potentially interesting for new applications such as biomedicine and food industry.   The deposition of carbon-based coatings (diamond-like coatings - DLC) with the addition of silver or copper will be also performed in this project by anode layer source (ALS) and PVD methods. DLC coatings are hard, inert and show good biocompatibility. With the addition of copper and silver, an anti-bacterial effect will be obtained. Adhesion of these coatings on a soft surface such as stainless steel, will be an additional challenge for further research. We will try to improve the adhesion by two ways: 1) the application of intermediate layers of metal (Cr and/or Ti), which reduces the stress between the substrate and the DLC coating, 2) addition of N2 to the reactive acetylene gas mix, which reduces hardness and increases the graphitization of the layer.   The next step in the project will be the physical, structural and mechanical characterization of the coatings prepared. For this purpose, the following surface characterization techniques will be used: scanning electron microscopy (SEM/EDS), transmission electron microscopy (TEM), atomic force microscope (AFM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Properties such as adhesion, hardness, thickness and density will be determined for each coating.   In the last part of the research project corrosion and tribo-corrosion characterizations will be performed, and the amount of the antibacterial effects of the coatings will be determined. Tribo-corrosion tests in physiological media will demonstrate the appropriateness of coatings both in terms of wear and corrosion.   A profound understanding of the mechanisms of corrosion is essential for the preparation of coatings with adequate corrosion protection. Potentiodynamic and galvanostatic techniques, as well as electrochemical impedance spectroscopy (EIS) and salt spray tests will be used to this purpose.   The antibacterial activity of coatings will be determined by survival bacteria tests.
Significance for science
The importance for science can be summarized in the following points. The microstructural investigations which have an emphasis on preparation and characterization of nanocrystalline multifunctional coatings were connected to electrochemical investigations. The field of research is interdisciplinary as it completes basic knowledge of electrochemistry, surface physics, metallurgy, tribology, plasma surface engineering and medicine. In addition to various electrochemical methods we also applied the most modern techniques of surface analysis. The research enabled us to find new, high-quality results, which could not have been obtained in individual fields only, i.e. either medicine or surface engineering. The interdisciplinary approach enables a better overview on the topics of implant protection in human body. The scientific impact is highlighted by many publications of the project group memebers in prestigeous international scientific journals, such as two papers in Corrosion Science (impact factor 3.6). We also need to mention, that one of these papers has been cited 49 times.
Significance for the country
The electrochemical processes for deposition of coatings (corrosion-resistant and decorative) are in widespread use in Slovenian industry. Due to ever tighter European and national environmental legislation, the users are forced to limit the health- and environmentally-problematic processes with the ecollogically acceptable vacuum processes. The PVD coatings have been realized as the only viable alternative. They enable the deposition of both metallic and ceramic coatings as well as various alloys. The work in the project strongly linked the insofar relatively too independent research groups in five institutions. An important fact is also that the partner institutions come from different Slovenian cities and from different types of research organizations. And finally, the results have a strong potential for better wear resistance of implants in human body, which will reduce the costs of health insurance.
Most important scientific results Annual report 2011, 2012, 2013, final report, complete report on dLib.si
Most important socioeconomically and culturally relevant results Annual report 2011, 2012, 2013, final report, complete report on dLib.si
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