Projects / Programmes source: ARIS

Evaluation of the range of plasma parameters suitable for nanostructuring of polymers on industrial scale

Research activity

Code Science Field Subfield
2.09.00  Engineering sciences and technologies  Electronic components and technologies   

Code Science Field
P240  Natural sciences and mathematics  Gases, fluid dynamics, plasmas 

Code Science Field
2.05  Engineering and Technology  Materials engineering 
plasma, flowing afterglow, polymer, discharge, nanostructuring, functionalization, wettability
Evaluation (rules)
source: COBISS
Researchers (22)
no. Code Name and surname Research area Role Period No. of publicationsNo. of publications
1.  37467  PhD Tilen Brecelj  Manufacturing technologies and systems  Researcher  2019 - 2020  26 
2.  31692  Tomaž Cimperšek    Technical associate  2017 
3.  07480  Marjan Drab  Electronic components and technologies  Researcher  2017 - 2020  67 
4.  35960  PhD Žiga Gosar  Manufacturing technologies and systems  Researcher  2017 - 2020  57 
5.  38207  PhD Matej Holc  Electronic components and technologies  Junior researcher  2017 - 2018  20 
6.  28480  PhD Ita Junkar  Medical sciences  Researcher  2017 - 2018  287 
7.  51483  Blaž Kaplan    Researcher  2019 - 2020 
8.  50410  MSc Andreja Knez  Chemical engineering  Researcher  2017 - 2018 
9.  24265  PhD Davor Kontić  Control and care of the environment  Researcher  2019 - 2020  116 
10.  15703  PhD Janez Kovač  Electronic components and technologies  Researcher  2017 - 2020  670 
11.  53287  PhD Marian Lehocky  Electronic components and technologies  Researcher  2019 - 2020  41 
12.  52435  Eva Levičnik    Technical associate  2020  10 
13.  10429  PhD Miran Mozetič  Electronic components and technologies  Head  2017 - 2020  1,352 
14.  06527  Branko Petrič  Electric devices  Researcher  2017 - 2020  23 
15.  33326  PhD Gregor Primc  Electronic components and technologies  Researcher  2018 - 2020  265 
16.  34451  PhD Nina Recek  Biotechnology  Researcher  2017 - 2020  85 
17.  37482  PhD Matic Resnik  Electronic components and technologies  Junior researcher  2017 - 2018  52 
18.  31482  Jure Slovša    Technical associate  2018 - 2020 
19.  51363  Tatjana Škulj  Economics  Researcher  2018 - 2019 
20.  52497  Maja Šukarov    Technical associate  2019 - 2020 
21.  20048  PhD Alenka Vesel  Electronic components and technologies  Researcher  2017 - 2020  689 
22.  31618  PhD Rok Zaplotnik  Electronic components and technologies  Researcher  2017 - 2020  304 
Organisations (4)
no. Code Research organisation City Registration number No. of publicationsNo. of publications
1.  0106  Jožef Stefan Institute  Ljubljana  5051606000  90,682 
2.  2341  INDUKTIO L.t.d.  Ljubljana  1840711  23 
3.  3253  ELVEZ, proizvodnja kabelske konfekcije in predelava plastičnih mas, d.o.o. (Slovene)  Višnja Gora  5569613  57 
4.  3522  VACUTECH, vakuumske tehnologije in sistemi d.o.o. (Slovene)  Ljubljana  1554824  67 
The range of plasma parameters suitable for nanostructuring, functionalization and optimal wettability of polyethylene therephthalate (PET), polyethylene (PE), polycarbonate (PC), polyphenylsulfide (PPS), polypropylene (PP) and ethylene tetrafluoroethylene (ETFE) in a reasonable treatment time will be evaluated. The flux of positively charged oxygen ions will be varied between about 1E17 m-2s-1 to about 1E20 m-2s-1 by adjusting discharge parameters, and the flux of neutral oxygen atoms onto the polymer surface from about 1E19 m-2s-1 to almost 1E24 m-2s-1. The flux of neutral atoms will be varied independently from discharge parameters (and thus the ion flux) using a movable recombinator. The corresponding fluences will be achieved by variation of treatment time. Plasma parameters will be measured by electrical and catalytic probes, optical spectroscopy and mass spectrometry, while surface finish by atomic force and scanning electron microscopies, X-ray photoelectron spectroscopy and secondary ion mass spectrometry. The polymers for which superhydrophilic surface finish will not be achievable by treatment in oxygen plasma for about 10 s (this is the requirement of our industrial partner and co-funding organization) will be treated using an innovative two-step process. The optimal range of plasma parameters will be determined in a small reactor of volume 1 litre. Upscaling will be realized in two steps, first with a medium-size reactor of volume 100 litres and finally in a large-size industrial reactor of volume 5000 litres. The coupling of discharges suitable for achieving the optimal range of plasma parameters as determined in the small reactor will be studied for large reactors first theoretically and then experimentally using alternative electrode configurations. Once optimal plasma parameters are achieved in the medium size reactor it will be proposed for pilot production of components for automotive industry in semi-continuous mode. Irrespective of company decision, an alternative coupling of discharge as well as a different RF generator will be tested also in the large reactor. The results of the research activity will enable our industrial partner to optimize the production of components for automotive industry. Innovative solutions will be protected by a couple of patent applications, one on the two-step process and another on innovative coupling between RF generator and gaseous plasma in large reactors. The scientific results will be published in topical journals in the field of plasma processing of polymer materials as well as applied surface science and a monograph on influence of reactive gaseous species on evolution of surface morphology and functional properties will be prepared.
Significance for science
As already stressed in the state of the art, extensive literature on plasma modification of polymers exists. In fact, only most representative papers were listed in #12 due to limitations of the forms. Authors used a variety of discharge configurations and reported the surface finish that was observed at their particular conditions. This approach may not be scientifically spotless since it is not the electrical discharge that interacts with polymers. The polymers are modified by reactive gaseous species, so the scientifically spotless description should be explanation of the surface finish by interaction with the species. Obviously, the fluxes of species onto the treated material should be known. Unfortunately, only a limited number of research groups have abilities to measure key plasma parameters.    The concentration of above mentioned species is difficult to determine. Density of positively charged ions and electron temperature are estimated using electrical (often called “Langmuir”) probes, but the high-frequency interferences make measurements difficult in the case of inductive coupling. From this point of view the cut-off probes perform better. The neutral atoms density is usually determined by TALIF (which is rather expensive), actinometry (which is not always reliable), or catalytic probes which should be deferentially pumped in order to allow for proper reading. The concentration of other particles is rarely measured. It is common to perform simulations such as our own (see scientific achievement #5).   Our reactors will be equipped with electrical and catalytic probes so the two major plasma parameters will be determined precisely enough. For concentration of metastables we shall take advantage of our long-lasting collaboration with theoreticians (as in scientific achievement #5).   The step beyond the state of the art will be therefore determination of surface effects (nanostructuring, functionalization, wettability) versus plasma parameters (fluxes of reactive species onto the polymer surface and corresponding fluences). As already stressed, our systems will allow for variation of the fluxes over several orders of magnitude.   Extremely important and definitely beyond the state of the art is our ability to vary the flux of neutral atoms irrespective from discharge parameters. As already mentioned, this will be realized by placing a movable recombinator in proximity of the polymer sample. The recombinator will influence the flux of atoms dramatically, but will hardly affect the flux of ions. To the best of our knowledge such a configuration has not been reported in scientific literature. The upper arguments will be sufficient for preparation of top-quality papers that will be submitted to topical journals of IF around 3: Plasma processing and polymers, Carbohydrate polymers, Plasma sources science and technology, Applied surface science, Surface and coatings technology etc. Comprehensive results will also allow for preparing of a monograph.
Significance for the country
The manufacturing sectors in Europe declined by 3 percentage points in the last decade to around 15% of GDP in 2012. tp://ec.europa.eu/enterprise/newsroom/cf/itemdetail.cfm?item_id=7297&lang=en&tpa_id=0&displayType=news&nl_id=1035 . The 2008 crisis led to a significant acceleration of European industrial decline, and industry needs targeted support to help it return to growth. Europe is still far from the 20% target of industry’s share in Europe’s GDP by 2020. To meet this goal we need to focus on reindustrialization, according to the current European research policy.     The Slovenian industry has been focused on production of devices and components for electro and automotive industry for decades. Many products are made from polymers or encapsulated into polymer housings. The production costs are not always optimized and neither is the quality of products. One reason is a lack of knowledge on advanced technologies suitable for tailoring surface properties of polymers or polymer-composites. The goal of this project proposal is to gain knowledge necessary for implementation of plasma technologies for tailoring surface properties of such materials, in particularly the surface morphology on nano-scale. The research results will be suitable for upscaling to industrial reactors thus enabling industry to estimate critically the applicability of such technologies in industrial environment. The Beneficial and Co-funding organization, company Elvez, is a rapidly growing company that currently employs about 300 workers. The strategy of the company is to improve the quality of products, use ecologically benign technologies and enter niches of higher value added. The proposed project perfectly fits this strategy.   The company currently employs commercial reactors for plasma treatment of polymer components. The processing is performed in the batch mode. The required treatment time is several minutes and the quality of surface finish is often problematic. The intermediate goal of the company is to improve the quality using existing reactors and to decrease the treatment time by modification of existing reactors. The final goal is to build a fully automatic production line applying continuous treatment. This would improve the quality and reduce the costs dramatically.   The further ambition of the company is to establish a joint-venture with an Institute spin-off and starts production of production lines employing plasma technologies. Namely, the company estimates the needs for such production lines to several 100 lines annually in its industry branch. As explained above in this proposal the innovative solutions will be protected by a couple of patent applications so the company expects large benefits from investing into such a research.
Most important scientific results Interim report, final report
Most important socioeconomically and culturally relevant results Interim report, final report
Views history