20.500.12556/RUL-119966
Časovno spremenljiva omočljivost lasersko teksturiranih jeklenih površin
Time-dependent wettability of laser-textured stainless steel surfaces
Površine s specifično omočljivostjo so uporabne na različnih področjih tehnike, v kmetijstvu, živilski industriji in medicini. V naravi omočljivost ali neomočljivost površin živali in rastline izrabljajo za preživetje. Najbolj poznan je primer superneomočljive površine lotosovega lista, ki se odraža tudi v samočistilnosti, ki preprečuje razrast bakterij in mikroorganizmov. V zaključni nalogi pokažemo, da je superneomočljive kovinske površine mogoče izdelati s kombinacijo laserskega teksturiranja kovinskih površin in njihovega naknadnega nizkotemperaturnega žarjenja v kontaminirani peči. Vzorce iz nerjavnega jekla smo lasersko teksturirali s pomočjo vlakenskega laserja z 28 ns bliski ter valovno dolžino 1060 nm. Zatem smo jih nizkotemperaturno žarili pri 100°C, 200°C, 250°C in 300°C. Pred, med in po žarjenju smo na vzorcih spremljali kot omočenja in kot skotaljenja vodne kapljice. Žarjenje smo ponovili v dveh pečeh pri enakih temperaturah z namenom identifikacije vpliva okoliške atmosfere na prehod iz omočljivega v neomočljivo stanje vzorcev. Ugotovili smo, da do prehoda iz omočljivega v neomočljivo stanje pride zaradi adsorpcije organskih kontaminantov, ki so bili prisotni v peči.
Surfaces with unique wettability are used in various fields of technology, in agriculture, food industry and medicine. The animals and plants exploit the hydrophilicity or hydrophobicity for their survival. The most famous example of the superhydrophobic surface in nature is the lotus leaf, which has also the self-cleaning ability and in this way, it prevents the growth of bacteria and microorganisms. In this BSc thesis, we demonstrate that superhydrophobic metal surfaces can be produced by a combination of laser texturing and their subsequent low-temperature annealing in a contaminated furnace. Stainless steel samples were laser textured by using a fibre laser radiating 28-ns pulses with a wavelength of 1060 nm. The laser-processed samples were further annealed at 100 °C, 200 °C, 250 °C and 300 °C. Before, during and after annealing, we measured the contact and the roll-off angle of water droplet. The annealing was repeated in two furnaces at the same temperatures in order to identify the influence of the surrounding atmosphere on the hydrophilic-to-hydrophobic transition of the laser-textured samples. We found that this transition occurs due to the adsorption of organic contaminants that were present in the furnace.
omočljivost
funkcionalizacija površin
laserski inženiring površin
lasersko teksturiranje
površinska napetost
hidrofilnost
hidrofobnost
wettability
surface functionalities
laser surface engineering
laser texturing
surface tension
hydrophilicity
hydrophobicity
true
false
false
[M. Modrijan]
Slovenski jezik
Angleški jezik
Zaključna naloga
2020-09-14 08:30:47
2020-09-14 08:30:51
2022-09-01 03:56:44
0000-00-00 00:00:00
2020
0
Ljubljana
0
XIV, 31 f.
0000-00-00
NiDoloceno
NiDoloceno
NiDoloceno
0000-00-00
0000-00-00
0000-00-00
544.722.3:532.61:621.9.04(043.2)
224325
32666115
6235.pdf
6235.pdf
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https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=134716
Fakulteta za strojništvo
0
0
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