Sessile droplet evaporation on patterned surfaces
In this study, the evaporation behaviour between suspension fluids and water droplets has been investigated on different substrates. The sizes of particles in the suspension fluids increases by a factor of ten sizes from 0.05μm, 0.5μm and 6μm. The substrates used are Al2O3, TiO2 flat and a patter...
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| Other Authors: | |
| Format: | Final Year Project (FYP) |
| Language: | English |
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Nanyang Technological University
2023
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| Online Access: | https://hdl.handle.net/10356/167269 |
| _version_ | 1824456720816013312 |
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| author | Ng, Aaron Chin Liang |
| author2 | Fei Duan |
| author_facet | Fei Duan Ng, Aaron Chin Liang |
| author_sort | Ng, Aaron Chin Liang |
| collection | NTU |
| description | In this study, the evaporation behaviour between suspension fluids and water droplets
has been investigated on different substrates. The sizes of particles in the suspension
fluids increases by a factor of ten sizes from 0.05μm, 0.5μm and 6μm. The substrates
used are Al2O3, TiO2 flat and a patterned micro pyramid substrate. For the patterned
substrate, a 0º and 45º line of sights are used. Both offer different properties such as
hydrophobicity. As such, the interaction and behaviour of the fluid are experimented
with using a combination of microscopy and a high-speed camera. Specifically, the
dimensions and contact angles of the droplets are taken throughout the evaporation
phase. Thereafter, a surface roughness profile is developed to detail the exact
deposition using a confocal microscopy. First, DI water droplets provide a good base
line for the substrate properties and a comparator for the suspension fluid droplets. The
results show the substrates differs in hydrophobicity. However, fluid with colloidal
particles overall increases the contact angle and decreases the dimensions of the
contact line which gave an overall increase in hydrophobicity. For the patterned
substrate at Ls0º, it increases further in hydrophobicity as the micro pyramid structures
acts as barrier. This is different at Ls45º where it was not as hydrophobic as Ls0º.
There were inherent directional properties of the micro pyramid substrate which
correlates to the wetting properties. Furthermore, the observation of the final dried
deposited pattern was that the outward capillary flow becomes less dominant as the
particle sizes increases. With a bigger particle size, the coffee-ring pattern becomes
less dominant which slowly transitions into a uniform pattern. This study provides
important insights into the mechanisms of how suspension fluids in the same
concentration behaves in the presence of different substrates with different properties. |
| first_indexed | 2025-02-19T03:58:36Z |
| format | Final Year Project (FYP) |
| id | ntu-10356/167269 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2025-02-19T03:58:36Z |
| publishDate | 2023 |
| publisher | Nanyang Technological University |
| record_format | dspace |
| spelling | ntu-10356/1672692023-05-27T16:50:45Z Sessile droplet evaporation on patterned surfaces Ng, Aaron Chin Liang Fei Duan School of Mechanical and Aerospace Engineering FeiDuan@ntu.edu.sg Engineering::Mechanical engineering::Fluid mechanics In this study, the evaporation behaviour between suspension fluids and water droplets has been investigated on different substrates. The sizes of particles in the suspension fluids increases by a factor of ten sizes from 0.05μm, 0.5μm and 6μm. The substrates used are Al2O3, TiO2 flat and a patterned micro pyramid substrate. For the patterned substrate, a 0º and 45º line of sights are used. Both offer different properties such as hydrophobicity. As such, the interaction and behaviour of the fluid are experimented with using a combination of microscopy and a high-speed camera. Specifically, the dimensions and contact angles of the droplets are taken throughout the evaporation phase. Thereafter, a surface roughness profile is developed to detail the exact deposition using a confocal microscopy. First, DI water droplets provide a good base line for the substrate properties and a comparator for the suspension fluid droplets. The results show the substrates differs in hydrophobicity. However, fluid with colloidal particles overall increases the contact angle and decreases the dimensions of the contact line which gave an overall increase in hydrophobicity. For the patterned substrate at Ls0º, it increases further in hydrophobicity as the micro pyramid structures acts as barrier. This is different at Ls45º where it was not as hydrophobic as Ls0º. There were inherent directional properties of the micro pyramid substrate which correlates to the wetting properties. Furthermore, the observation of the final dried deposited pattern was that the outward capillary flow becomes less dominant as the particle sizes increases. With a bigger particle size, the coffee-ring pattern becomes less dominant which slowly transitions into a uniform pattern. This study provides important insights into the mechanisms of how suspension fluids in the same concentration behaves in the presence of different substrates with different properties. Bachelor of Engineering (Mechanical Engineering) 2023-05-25T05:52:26Z 2023-05-25T05:52:26Z 2023 Final Year Project (FYP) Ng, A. C. L. (2023). Sessile droplet evaporation on patterned surfaces. Final Year Project (FYP), Nanyang Technological University, Singapore. https://hdl.handle.net/10356/167269 https://hdl.handle.net/10356/167269 en application/pdf Nanyang Technological University |
| spellingShingle | Engineering::Mechanical engineering::Fluid mechanics Ng, Aaron Chin Liang Sessile droplet evaporation on patterned surfaces |
| title | Sessile droplet evaporation on patterned surfaces |
| title_full | Sessile droplet evaporation on patterned surfaces |
| title_fullStr | Sessile droplet evaporation on patterned surfaces |
| title_full_unstemmed | Sessile droplet evaporation on patterned surfaces |
| title_short | Sessile droplet evaporation on patterned surfaces |
| title_sort | sessile droplet evaporation on patterned surfaces |
| topic | Engineering::Mechanical engineering::Fluid mechanics |
| url | https://hdl.handle.net/10356/167269 |
| work_keys_str_mv | AT ngaaronchinliang sessiledropletevaporationonpatternedsurfaces |