Silica-coated metallic nanoparticle-based hierarchical super-hydrophobic surfaces fabricated by spin-coating and inverse nanotransfer printing

Abstract

By combining spin coating and inverse nanotransfer printing, silica-coated gold nanoparticles are patterned onto polydimethylsiloxane (PDMS) superhydrophobic surfaces to form a hierarchical structure. A layer of nanoparticles is spin-coated on a flat silicon substrate serving as the stamp, which is then transferred to the raised regions of PDMS surfaces. Our inverse nanotransfer printing is in contrast to the standard nanotransfer printing, which transfers metal from the raised regions of a stamp to a flat PDMS surface. The fabricated hierarchical surface exhibits a higher contact angle and delays the Cassie-Wenzel transition during evaporation of a sessile droplet, indicating an improvement of superhydrophobicity. Finally, we demonstrate that the fabricated nanoparticle-based superhydrophobic surfaces can enhance the Raman intensity and significantly decrease the surface-enhanced Raman scattering detection limit.

Tailoring Materials with Specific Wettability in Biomedical Engineering

“…[ 59 , 60 ] With the development of science and technology, many advanced methods have been put forward to prepare materials especially biomaterials with specific wettability such as superwetting materials and SLIPS. [ 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 ,…”

“…To enhance the superwetting behavior of materials, spin‐coating technique is usually combined with other physical methods. [ 89 , 90 ] Similar to the spin‐coating method, spraying method is also aimed at decorating the surfaces with a low surface energy layer to impart surfaces with enhanced wettability, through spraying and subsequently solidifying the solutions on substrates. [ 91 ] During the spray‐coating process, a glue layer is usually sprayed on the substrate before the spray of the nanoparticle suspensions to enhance the adhesion of functional particles.…”

Producing Fluorine- and Lubricant-Free Flexible Pathogen- and Blood-Repellent Surfaces Using Polysiloxane-Based Hierarchical Structures

“…9,10 This increased roughness provides the basis for Cassie−Baxter or Wenzel wetting states. 11,12 Conventional techniques to accomplish roughness include etching, 13−15 electrochemical deposition, 16,17 templating, 18,19 spray coatings, 20,21 sputtering followed by thermal annealing, 22 spin coating, 23 and sol−gel processes. 24 To closely replicate the lotus effect, researchers commonly employ a series of manufacturing steps to introduce a hierarchy of structures ranging from the nanometer to hundreds of micrometer lengthscales.…”

“…To develop repellent materials, researchers aim to create superhydrophobic surfaces characterized by contact angles >150 degrees and sliding angles <10° . Strategies such as physical modifications to add roughness inspired by the multiscale texture found on lotus leaves and butterfly wings are commonly used to create repellent surfaces. , This increased roughness provides the basis for Cassie–Baxter or Wenzel wetting states. , Conventional techniques to accomplish roughness include etching, − electrochemical deposition, , templating, , spray coatings, , sputtering followed by thermal annealing, spin coating, and sol–gel processes . To closely replicate the lotus effect, researchers commonly employ a series of manufacturing steps to introduce a hierarchy of structures ranging from the nanometer to hundreds of micrometer lengthscales. − By implementing multiple-step approaches, both micro- and nanoscale features are established on surfaces, which can be employed for biorepellency. ,, While these techniques have demonstrated high performance in terms of superhydrophobicity and pathogen repellency, it is often difficult to produce these surfaces on a large scale due to the complexities of the multistep manufacturing methods and the prohibitive costs of the reagents and processes involved …”

Template assisted preparation of silicone (polydimethylsiloxane) elastomers and their self-cleaning application

“…[13][14][15] Compared to multiple processes, a one-step process is more desirable for obtaining robust SHSEs as any preceding or subsequent process (such as coating) could destroy the surface micro/nano-structures, which would lead to the loss of superhydrophobicity. Several methods have been applied to achieve surface superhydrophobicity, including sol-gel methods, 16,17 laser-induced methods, 18 electrochemical methods, 19 plasma treatment, 20,21 phase separation methods, 22 spin-coating, 23 template methods. 24,25 However, robust superhydrophobicity is even more challenging since surface superhydrophobicity is slowly decreased by adhesion of oily contamination in practical uses.…”