The influence of Wettability on the Droplet Impact onto Micro-Structured Surfaces

• Autor(a) principal: Ribeiro, Daniela
• Data de Publicação: 2021
• Outros Autores: Foltyn, Patrick, Silva, André, Lamanna, Grazia, Weigand, Bernhard
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/12162
• topic: Micro-structured surfaces; Hygrophilic; Hygrophobic; Drop impact; Wettability

The flourishing of applications in need of self-cleaning mechanisms increased the search forwater repellent hydrophobic surfaces with induced roughness. Disclosing the small-scale inter-face phenomena on the wetting behavior is essential to design efficient hydrophobic materialswith defined topography. On the other hand, the spreading behavior concerning the forma-tion of thin films on a surface is required to assure the quality of spray cooling and coatings.The contact angle undoubtedly plays an important role in the droplet impact, providing differ-ent outcomes. Moreover, an open question is, how surface topography can affect the impactprocess. Therefore, to evaluate these matters, different surface patterns were manufacturedto assess the surface topography influence on the impact dynamic behavior. Additionally, thewettability of the micro-structured surfaces was flexibly influenced through plasma activationand plasma polymerization. The impact of distilled water and isopropanol droplets on the dif-ferent surface patterns was captured from three perspectives providing high-quality images ofthe phenomena. Different surface morphologies can be obtained depending on the surfacemicro-structures and wettability, affecting spreading shape and evolution. The fluid penetrationwithin the micro-structures is a key feature influencing not only the structures of the outcomesbut also the transition between regimes.