Velikostna separacija vodnih kapljic na superhidrofobnih površinah

magistrsko delo magistrskega študijskega programa II. stopnje Strojništvo

Samo Jereb (Author), Iztok Golobič (Mentor), Matevž Zupančič (Co-mentor)

Abstract

Slaba omočljivost superhidrofobnim površinam ponuja številne aplikacije, kot so samočistilnost, antikorozivnost in preprečevanje zmrzovanja. V okviru magistrske naloge smo obravnavali uporabo superhidrofobnih površin za velikostno separacijo kapljic. Razvili smo teoretični model za napoved velikosti kapljice pri prehodu skozi odprtino tanke folije. Rezultate smo primerjali z eksperimentalno določenimi velikostmi kapljic pri prehodu skozi lasersko izrezane odprtine tanke bakrene folije z lasersko strukturirano in hidrofobizirano površino, ki je izkazovala superhidrofobne lastnosti. Pri velikosti odprtin od 1,2 do 2 mm, kjer je velikost kapljic pri prehodu manjša od kapilarne dolžine kapljevine, je odstopanje teoretično napovedane velikosti premera od izmerjene velikosti manj kot 20 %. Z zmanjševanjem velikosti odprtin se natančnost teoretičnega modela povečuje in doseže manj kot 10% odstopanje v primeru odprtin s premerom manjšim od 1,5 mm. Predstavili smo tudi metodologijo za dinamično velikostno separacijo kapljic z uporabo bakrenih mrežic s superhidrofobnimi površinami, ki so bile pripravljene z jedkanjem površine ter nanosom hidrofobnih snovi. Velikostna separacija kapljic je odvisna od mejne velikosti kapljic, pri kateri kapljice še lahko prehajajo skozi odprtine mrežice. Eksperimentalno smo določili mejno velikost kapljic za mrežico z odprtinami velikosti 2,46 mm, ki se nahaja med 4,2 in 4,5 mm.

Keywords

magistrske naloge;superhidrofobnost;velikostna separacija kapljic;teoretični model;bakrena mrežica;

Data

Language:	Slovenian
Year of publishing:	2022
Typology:	2.09 - Master's Thesis
Organization:	UL FS - Faculty of Mechanical Engineering
Publisher:	[S. Jereb]
UDC:	531.732:544.722.132(043.2)
COBISS:	119551491
Views:	47
Downloads:	21
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Water droplet size separation on superhydrophobic surfaces
Secondary abstract:	Low wettability gives superhydrophobic surfaces numerous applications, such as self-cleaning, anti-corrosion and anti-icing. In this work, we analyzed the usage of superhydrophobic surfaces in droplet size separation. We developed a theoretical model for predicting the size of a droplet passing through a hole in a thin foil. We compared the results with experimentally determined droplet sizes passing through laser cut holes in a thin copper foil with laser textured and hydrophobized surfaces, which displayed superhydrophobic characteristics. For holes with diameters of 1.2 to 2.0 mm, at which the size of the droplets passing through the hole is lesser than the capillary length of the fluid, the deviation of the theoretically predicted size of the droplet from the measured size is less than 20 %. By reducing the size of the hole the accuracy of the theoretical model increases, as the deviation is less than 10 % for holes with diameters smaller than 1.5 mm. We presented the methodology for dynamic droplet size separation using copper meshes with superhydrophobic surfaces, which were prepared by etching and coating with hydrophobic substances. The droplet size separation depends on the limiting size of the droplets, at which the droplets can still pass through the openings of the mesh. We experimentally determined the limiting size of the droplets for a mesh with 2.46 mm openings, which is located between 4.2 and 4.5 mm.
Secondary keywords:	master thesis;superhydrophobicity;droplet size separation;theoretical model;copper mesh;
Type (COBISS):	Master's thesis/paper
Study programme:	0
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. Ljubljana, Fak. za strojništvo
Pages:	XXII, 56 str.
ID:	16279631