Browsing by Subject "Superhydrophobic coatings"

Now showing 1 - 3 of 3

Open Access
Blood repellent superhydrophobic surfaces constructed from nanoparticle-free and biocompatible materials
(Elsevier BV, 2021-09) Çelik, N.; Şahin, F; Ruzi, M.; Yay, M.; Ünal, Ekrem; Önses, Mustafa Serdar
Durable and environment friendly superhydrophobic surfaces are needed for a set of important applications. Biomedical applications, in particular, impose stringent requirements on the biocompatibility of the materials used in the fabrication of superhydrophobic surfaces. In this study, we demonstrate the fabrication of mechanically durable superhydrophobic surfaces via an in-situ structuring strategy starting from natural carnauba wax and biocompatible polydimethylsiloxane (PDMS) materials. The transfer of the structure of the paper to a free-standing PDMS film provided the microscale structure. On top of this structured surface, the wax was spray-coated, initially resulting in a relatively homogeneous film with limited liquid repellence. The key in achieving superhydrophobicity was rubbing the surface for in-situ generation of a finely textured wax coating with a water contact angle of 169° and a sliding angle of 3°. The hierarchically structured surface exhibits mechanical robustness as demonstrated with water impact and linear abrasion tests. We finally demonstrate repellence of the surfaces against a range of blood products including platelet suspension, erythrocyte suspension, fresh plasma, and whole blood.
Open Access
Robust superhydrophilic patterning of superhydrophobic ormosil surfaces for high-throughput on-chip screening applications
(Royal Society of Chemistry, 2016) Beyazkilic, P.; Tuvshindorj, U.; Yildirim, A.; Elbuken, C.; Bayındır, Mehmet
This article describes a facile method for the preparation of two-dimensionally patterned superhydrophobic hybrid coatings with controlled wettability. Superhydrophobic coatings were deposited from nanostructured organically modified silica (ormosil) colloids that were synthesized via a simple sol-gel method. On the defined areas of the superhydrophobic ormosil coatings, stable wetted micropatterns were produced using Ultraviolet/Ozone (UV/O) treatment which modifies the surface chemistry from hydrophobic to hydrophilic without changing the surface morphology. The degree of wettability can be precisely controlled depending on the UV/O exposure duration; extremely wetted spots with water contact angle (WCA) of nearly 0° can be obtained. Furthermore, we demonstrated high-throughput biomolecular adsorption and mixing using the superhydrophilic patterns. The proposed superhydrophilic-patterned nanostructured ormosil surfaces with their simple preparation, robust and controlled wettability as well as adaptability on flexible substrates, hold great potential for biomedical and chemical on-chip analysis.
Open Access
Transferring the structure of paper for mechanically durable superhydrophobic surfaces
(Elsevier, 2020-10-24) Torun, İ.; Celik, N.; Ruzi, M.; Önses, Mustafa Serdar
Solution-phase deposition of nanomaterials represents a highly promising technology with strong industrial application potential for the fabrication of superhydrophobic surfaces. An important barrier towards the adaptation of such materials and processes in a broad range of applications is the limited mechanical durability of the nanostructures. Herein, we present a universal solution to this challenge by benefiting from the unique micro-structure of paper. Our approach is based on transferring the structure of paper into a target material, to form a mechanical protection layer for nanomaterials that were deposited from solution-phase, i.e. spray-coating. We demonstrate this concept through the transfer of the structure of paper to a free-standing PDMS film using a simple molding process. Spraying a dispersion of alkyl-silane functionalized silica nanoparticles on the structured free-standing film results in a hierarchically structured superhydrophobic surface with a water contact angle of 175° ± 2° and a sliding angle <2° ± 1°. The fabricated superhydrophobic surface displays high levels of mechanical, chemical and thermal stability. The robust, inexpensive, scalable, flexible, and environmentally friendly nature of the presented approach may be a key enabler in superhydrophobic coating applications.