1. Mechanically Switchable Wetting Petal Effect in Self-Patterned Nanocolumnar Films on Poly(dimethylsiloxane)
- Author
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Julian Parra-Barranco, Ana Borras, Carmen López-Santos, Agustín R. González-Elipe, Juan R. Sanchez-Valencia, Angel Barranco, Universidad de Sevilla. Departamento de Física Atómica, Molecular y Nuclear, and Universidad de Sevilla. Departamento de Física Aplicada I
- Subjects
Droplet sliding ,Materials science ,General Chemical Engineering ,Microfluidics ,02 engineering and technology ,Surface finish ,Deformation (meteorology) ,010402 general chemistry ,Elastomer ,droplet sliding ,self-surface patterning ,01 natural sciences ,Article ,chemistry.chemical_compound ,Anisotropic wetting ,PDMS ,General Materials Science ,Diiodomethane ,Composite material ,QD1-999 ,Polydimethylsiloxane ,anisotropic wetting ,Self‐surface patterning ,GLAD coatings ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Chemistry ,chemistry ,Physical vapor deposition ,Wetting ,0210 nano-technology - Abstract
Switchable mechanically induced changes in the wetting behavior of surfaces are of para-mount importance for advanced microfluidic, self‐cleaning and biomedical applications. In this work we show that the well‐known polydimethylsiloxane (PDMS) elastomer develops self‐patterning when it is coated with nanostructured TiO2 films prepared by physical vapor deposition at glancing angles and subsequently subjected to a mechanical deformation. Thus, unlike the disordered wrinkled surfaces typically created by deformation of the bare elastomer, well‐ordered and aligned micro‐scaled grooves form on TiO2/PDMS after the first post‐deposition bending or stretching event. These regularly patterned surfaces can be reversibly modified by mechanical deformation, thereby inducing a switchable and reversible wetting petal effect and the sliding of liquid droplets. When performed in a dynamic way, this mechanical actuation produces a unique capacity of liquid droplets (water and diiodomethane) transport and tweezing, this latter through their selective capture and release depending on their volume and chemical characteristics. Scanning electron and atomic force microscopy studies of the strained samples showed that a dual‐scale rough-ness, a parallel alignment of patterned grooves and their reversible widening upon deformation, are critical factors controlling this singular sliding behavior and the possibility to tailor their response by the appropriate manufacturing of surface structures. European Union 899352 Ministerio de Ciencia e Innovación PID2019- 110430GB-C21, PID2019-109603RA-I0, MAT2013-40852-R, MAT2013- 42900-P Ministerio de Economía y Competitividad 201560E055 Junta de Andalucía AT17-6079, P18-RT-3480
- Published
- 2021
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