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Effect of Structure Hierarchy for Superhydrophobic Polymer Surfaces Studied by Droplet Evaporation
Super-hydrophobic natural surfaces usually have multiple levels of structure hierarchy. Here, we report on the effect of surface structure hierarchy for droplet evaporation. The two-level hierarchical structures studied comprise micro-pillars superimposed with nanograss. The surface design is fully...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6215152/ https://www.ncbi.nlm.nih.gov/pubmed/30322171 http://dx.doi.org/10.3390/nano8100831 |
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author | Okulova, Nastasia Johansen, Peter Christensen, Lars Taboryski, Rafael |
author_facet | Okulova, Nastasia Johansen, Peter Christensen, Lars Taboryski, Rafael |
author_sort | Okulova, Nastasia |
collection | PubMed |
description | Super-hydrophobic natural surfaces usually have multiple levels of structure hierarchy. Here, we report on the effect of surface structure hierarchy for droplet evaporation. The two-level hierarchical structures studied comprise micro-pillars superimposed with nanograss. The surface design is fully scalable as structures used in this study are replicated in polypropylene by a fast roll-to-roll extrusion coating method, which allows effective thermoforming of the surface structures on flexible substrates. As one of the main results, we show that the hierarchical structures can withstand pinning of sessile droplets and remain super-hydrophobic for a longer time than their non-hierarchical counterparts. The effect is documented by recording the water contact angles of sessile droplets during their evaporation from the surfaces. The surface morphology is mapped by atomic force microscopy (AFM) and used together with the theory of Miwa et al. to estimate the degree of water impregnation into the surface structures. Finally, the different behavior during the droplet evaporation is discussed in the light of the obtained water impregnation levels. |
format | Online Article Text |
id | pubmed-6215152 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-62151522018-11-14 Effect of Structure Hierarchy for Superhydrophobic Polymer Surfaces Studied by Droplet Evaporation Okulova, Nastasia Johansen, Peter Christensen, Lars Taboryski, Rafael Nanomaterials (Basel) Article Super-hydrophobic natural surfaces usually have multiple levels of structure hierarchy. Here, we report on the effect of surface structure hierarchy for droplet evaporation. The two-level hierarchical structures studied comprise micro-pillars superimposed with nanograss. The surface design is fully scalable as structures used in this study are replicated in polypropylene by a fast roll-to-roll extrusion coating method, which allows effective thermoforming of the surface structures on flexible substrates. As one of the main results, we show that the hierarchical structures can withstand pinning of sessile droplets and remain super-hydrophobic for a longer time than their non-hierarchical counterparts. The effect is documented by recording the water contact angles of sessile droplets during their evaporation from the surfaces. The surface morphology is mapped by atomic force microscopy (AFM) and used together with the theory of Miwa et al. to estimate the degree of water impregnation into the surface structures. Finally, the different behavior during the droplet evaporation is discussed in the light of the obtained water impregnation levels. MDPI 2018-10-13 /pmc/articles/PMC6215152/ /pubmed/30322171 http://dx.doi.org/10.3390/nano8100831 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Okulova, Nastasia Johansen, Peter Christensen, Lars Taboryski, Rafael Effect of Structure Hierarchy for Superhydrophobic Polymer Surfaces Studied by Droplet Evaporation |
title | Effect of Structure Hierarchy for Superhydrophobic Polymer Surfaces Studied by Droplet Evaporation |
title_full | Effect of Structure Hierarchy for Superhydrophobic Polymer Surfaces Studied by Droplet Evaporation |
title_fullStr | Effect of Structure Hierarchy for Superhydrophobic Polymer Surfaces Studied by Droplet Evaporation |
title_full_unstemmed | Effect of Structure Hierarchy for Superhydrophobic Polymer Surfaces Studied by Droplet Evaporation |
title_short | Effect of Structure Hierarchy for Superhydrophobic Polymer Surfaces Studied by Droplet Evaporation |
title_sort | effect of structure hierarchy for superhydrophobic polymer surfaces studied by droplet evaporation |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6215152/ https://www.ncbi.nlm.nih.gov/pubmed/30322171 http://dx.doi.org/10.3390/nano8100831 |
work_keys_str_mv | AT okulovanastasia effectofstructurehierarchyforsuperhydrophobicpolymersurfacesstudiedbydropletevaporation AT johansenpeter effectofstructurehierarchyforsuperhydrophobicpolymersurfacesstudiedbydropletevaporation AT christensenlars effectofstructurehierarchyforsuperhydrophobicpolymersurfacesstudiedbydropletevaporation AT taboryskirafael effectofstructurehierarchyforsuperhydrophobicpolymersurfacesstudiedbydropletevaporation |