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## Experimental investigation of droplet's spreading on super-hydrophobic surfaces with a regular first order structure

### Kacper Stasiuk

#### Abstract

Thesis describes, investigates and analyses dynamic contact of droplet at super-hydrophobic surface with a regular first order structure. The main goal is to measure wetting ability of new surface samples manufactured by researchers at ITME – Institute of Electronic Materials Technology. Next, the surfaces with identical composition and coating, differ only in first order structure are compared. It shows, how the microstructure of surface impacts its hydrophobic properties. The first part contains theoretical introduction and the description of experimental methods. Some basic principles of droplet’s dynamic contact with a solid surface are presented. Moreover, the most important properties and manufacturing process of hydrophobic surfaces is provided. Then, the test stand is presented and the most important devices are shortly introduced. The software that has been used is also outlined and crucial, recommended settings are highlighted. At the end of that part, the surfaces and experimental cases are presented. Two silicon surfaces are investigated; they are covered with same, PVDF polymer coating, differ only in the microstructure. For both of them, the droplet impact at four experimental cases is measured – at initial height of drop release of 30, 50, 70 and 140 mm. In order to avoid statistical errors, for each of eight cases, measurements are repeated around 30 times. The second part is focused on results presentation and analysis. At the beginning, only images and video files are taken into consideration. It gives some general overview about the differences in droplet impact for different experimental cases. Next, using LabVIEW programs, numerical results of the crucial quantities - contact angle and maximal diameter of droplet, are obtained. Finally, these values for both surfaces are compared, leading to interesting conclusions. The last part is the conclusion of the whole research that has been done. The results are considered as reliable and valuable – they confirm previous papers’ results and initial expectations. Next, some future recommendations in order to improve the quality of experiment are provided. Results lead to the statement, that silicon plate with a PVDF polymer coating has good hydrophobic properties. Moreover, some modifications of the microstructure in that surfaces, influence droplet impact phenomena. Proper structure can additionally improve hydrophobic characteristics of material. It is worth to continue research area of droplet-solid dynamic contacts as it concern many important branches, like aviation, power industry, agriculture or criminalistics.
Diploma type
Engineer's / Bachelor of Science
Diploma type
Engineer's thesis
Author
Kacper Stasiuk (FPAE) Kacper Stasiuk,, Faculty of Power and Aeronautical Engineering (FPAE)
Title in Polish
Supervisor
Grzegorz Sobieraj (FPAE/IAAM) Grzegorz Sobieraj,, The Institute of Aeronautics and Applied Mechanics (FPAE/IAAM)Faculty of Power and Aeronautical Engineering (FPAE)
Certifying unit
Faculty of Power and Aeronautical Engineering (FPAE)
Affiliation unit
The Institute of Aeronautics and Applied Mechanics (FPAE/IAAM)
Study subject / specialization
, Mechanika i Budowa Maszyn
Language
(en) English
Status
Finished
Defense Date
18-02-2016
Issue date (year)
2016
Pages
48
Internal identifier
MEL; PD-3592
Reviewers
Janusz Piechna (FPAE/IAAM) Janusz Piechna,, The Institute of Aeronautics and Applied Mechanics (FPAE/IAAM)Faculty of Power and Aeronautical Engineering (FPAE) Grzegorz Sobieraj (FPAE/IAAM) Grzegorz Sobieraj,, The Institute of Aeronautics and Applied Mechanics (FPAE/IAAM)Faculty of Power and Aeronautical Engineering (FPAE)
Keywords in Polish
Kropla, Superhydrofobowość, Kontakt dynamiczny, Mikrostruktura.
Keywords in English
Droplet, Super-hydrophobicity, Dynamic contact, Microstructure.
Abstract in Polish
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Praca_inz_Kacper_Stasiuk.pdf
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Identyfikator pracy APD: 9063

Uniform Resource Identifier
https://repo.pw.edu.pl/info/bachelor/WUT093c5695f8c148c180265705af4c697c/
URN
urn:pw-repo:WUT093c5695f8c148c180265705af4c697c

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