project leader Dr Aleksandra Kocijan is a member of editorial board of the journal with IF
C.01 Editorial board of a foreign/international collection of papers/book
COBISS.SI-ID: 106193664Report on surface engineering by a nanosecond fiber laser on metal surfaces for various applications
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 15846427This work presents the results of a few - month observation of wetting and corrosion properties of fiber - laser - textured (SP-020P-A-HS-S-A-Y) stainless steel AISI 316L. The samples were prepared either uncoated by varying the distance between laser - produced micro-channels leading to different surface roughnesses or laser - textured and coated with epoxy resin, or with epoxy resin filled with FAS - TiO2 nanoparticles (epoxy/FAS - TiO2). We performed a comparative study on the samples kept under ambient conditions and in conditions with reduced air pressure and humidity. Optical profilometry and scanning electron microscopy were used to analyze the average surface roughness and morphology of laser - textured steel surfaces. Contact angles were monitored on a daily basis for all samples under ambient conditions and in conditi ons with reduced air pressure and humidity. Potentiodynamic measurements were performed on fresh - prepared and aged uncoated and coated laser - textured samples. The results have shown that superhydrophobicity of steel can be achieved either indirectly by agi ng the laser - textured surface or directly by application of the epoxy/FAS - TiO 2 coating. Ambient conditions have a significant impact on changes of wettability of laser - textured steel without coatings, but they do not affect the aging of coated laser - textur ed surfaces. Coated surfaces show improved corrosion resistance compared to uncoated laser - textured surfaces.
B.04 Guest lecture
COBISS.SI-ID: 16285467TiO2/epoxy coatings were successfully applied to the surface of AISI 316L stainless steel to change the wetting properties, with the aim being to improve the biocompatibility of the superhydrophobic/superhydrophilic surfaces. Contact-angle measurements were used to evaluate the wetting properties of the non-coated, epoxy-coated, as-received TiO2/epoxy-coated and fluoroalkylsilane (FAS)-TiO2/epoxy-coated substrates. The as-received TiO2/epoxy coating and FAS-TiO2/epoxy coating showed superhydrophilic and superhydrophobic characteristics, respectively. The average surface roughness (Sa) of the superhydrophobic surface was higher compared to the superhydrophilic surface due to the formation of agglomerates. The biocompatibility evaluated by cell attachment showed that AISI 316L stainless steel with a hydrophilic nature and low Sa is the most favourable surface for bone osteosarcoma cells (MG-63) growth. On the other hand, the two limiting cases of surfaces, superhydrophilic and superhydrophobic coatings with increased roughness compared to AISI 316L, showed lower biocompatibility.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 1393834Superhydrophilic and superhydrophobic TiO2/epoxy coatings were prepared with as-received TiO2 and fluoroalkylsilane (FAS) functionalised TiO2 nanoparticles and successfully applied to the surface of AISI 316L stainless steel. The wetting properties of the coatings were confirmed with static contact-angle measurements. The corrosion performance of the investigated coatings was studied by electrochemical impedance spectroscopy (EIS). The open-circuit impedance spectra of the AISI 316L stainless steel, the epoxy-coated AISI 316L, the as-received TiO2/epoxy coating on AISI 316L and the FAS-TiO2/epoxy coating on AISI 316L were measured in simulated physiological Hank’s solution. Bode plots and Nyquist diagrams were used to evaluate the corrosion properties of the investigated coatings. The results show the enhanced corrosion resistance of surface-modified stainless steel, especially in the case of the superhydrophobic FAS-TiO2/epoxy coating. The biocompatibility evaluated by cell attachment showed that AISI 316L stainless steel with a hydrophilic nature and low Sa is the most favourable surface for bone osteosarcoma cells (MG-63) growth. On the other hand, the two limiting cases of surfaces, superhydrophilic and superhydrophobic coatings with increased roughness compared to AISI 316L, showed lower biocompatibility.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 1349290