Dynamics of thin precursor film in wetting of nanopatterned surfaces.

Autor:	Anand U; Department of Physics, National University of Singapore, Singapore 117551.; Centre for BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore 117557.; Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117546., Ghosh T; Department of Physics, National University of Singapore, Singapore 117551.; Centre for BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore 117557., Aabdin Z; Centre for BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore 117557.; Institute for Materials Research and Engineering, Agency for Science, Technology and Research, Singapore 138634., Koneti S; Department of Physics, National University of Singapore, Singapore 117551.; Centre for BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore 117557., Xu X; Interuniversity Microelectronics Centre (imec), Leuven B-3001, Belgium., Holsteyns F; Interuniversity Microelectronics Centre (imec), Leuven B-3001, Belgium., Mirsaidov U; Department of Physics, National University of Singapore, Singapore 117551; mirsaidov@nus.edu.sg.; Centre for BioImaging Sciences, Department of Biological Sciences, National University of Singapore, Singapore 117557.; Centre for Advanced 2D Materials and Graphene Research Centre, National University of Singapore, Singapore 117546.; Department of Materials Science and Engineering, National University of Singapore, Singapore 117575.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2021 Sep 21; Vol. 118 (38).
DOI:	10.1073/pnas.2108074118
Abstrakt:	The spreading of a liquid droplet on flat surfaces is a well-understood phenomenon, but little is known about how liquids spread on a rough surface. When the surface roughness is of the nanoscopic length scale, the capillary forces dominate and the liquid droplet spreads by wetting the nanoscale textures that act as capillaries. Here, using a combination of advanced nanofabrication and liquid-phase transmission electron microscopy, we image the wetting of a surface patterned with a dense array of nanopillars of varying heights. Our real-time, high-speed observations reveal that water wets the surface in two stages: 1) an ultrathin precursor water film forms on the surface, and then 2) the capillary action by nanopillars pulls the water, increasing the overall thickness of water film. These direct nanoscale observations capture the previously elusive precursor film, which is a critical intermediate step in wetting of rough surfaces. Competing Interests: The authors declare no competing interest.
Databáze:	MEDLINE
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