Razvoj merilne proge za ovrednotenje hitrosti kapilarnega vleka strukturiranih površin

Panjan, Nejc (author), Golobič, Iztok (mentor), Može, Matic (comentor)

V zaključni nalogi smo obravnavali problem ovrednotenja interakcije superhidrofilne površine s kapljevitim medijem, saj klasična metoda merjenja kota omočenja statične kapljice, ne omogoča ustreznega ovrednotenja. Uporabili smo metodo ovrednotenja hitrosti kapilarnega vleka, pri kateri merimo hitrost iztekanja kapljevine iz kapilare ob stiku s površino trdne snovi. V ta namen smo razvili merilno progo in z njo izvedli meritve na različno obdelanih vzorcih. Uporabili smo bakrene ploščice in z različnimi vzorci strukturiranja izdelali superhidrofilne površine. Z merilno progo smo beležili časovno odvisnost spremembe višine kapljevine v kapilari, spreminjanje višine pa smo merili s hitro kamero. Meritve smo izvedli s cevko z notranjim premerom 0,5 mm, v kateri je bilo približno 1 µL destilirane vode. Po obdelavi posnetkov meritev smo dobili grafe premika gladine kapljevine v kapilari, iz katerih smo lahko določili hitrost kapilarnega vleka vzorca. Na bakrenih površinah smo naredili križne vzorce z različnimi razmiki med črtami in ugotovili, da so hitrosti kapilarnega vleka največje na vzorcu z najmanjšim razmikom. S povečevanjem razmika med črtami križnega vzorca, se hitrost kapilarnega vleka zmanjšuje.

• Language: Slovenian
• Keywords: superhidrofilnost, lasersko teksturiranje, omočljivost, hitrost kapilarnega vleka, merilna proga
• Work type: Final paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [N. Panjan]
• Year: 2022
• Number of pages: XV, 48 f.
• PID: 20.500.12556/RUL-139867
• UDC: 544.7:621.9.048.7(043.2)
• COBISS.SI-ID: 122521603
• Publication date in RUL: 08.09.2022

Secondary language

• Language: English
• Title: Development of an experimental setup for evaluation of wicking velocity of textured surfaces

Abstract

This study evaluates the interaction of the fluid with the superhidrophility surface, as the classic method of measuring the wetting angle of a static droplet does not allow an adequate evaluation. The method based on the measurement of wicking velocity was applied for this purpose. This approach was used to measure the speed of the liquid when flowing out of the capillary tube that was in contact with the surface. The necessary experimental setup used to perform measurements on various samples has been developed. As superhidrophilic surfaces the copper plates with different patterns made by laser modification were used. The time dependence of the liquid height in the capillary was measured with high-speed camera. The measurements have been done with a tube that contained approximately 1 μL of distilled water. The inner diameter of tube was 0,5 mm. By analysing images taken with the high-speed camera the wicking velocity of the samples modified by laser was determined. It was detected that the wicking velocity is the highest on the sample with the smallest spacing. By increasing the spacing between the lines of the cross pattern the wicking velocity decreases.

• Keywords: superhidrophility, laser texturing, wettability, wicking velocity, experimental setup