Abdullah Alkandary
Kuwait Institute for Scientific Research
Abdullah graduated with a bachelor's degree in nuclear engineering from Penn State University. He started his professional career at Kuwait Institute for Scientific Research as a research assistant in Renewable Energy. Currently is a research associate in Nanotechnology and Advanced Materials at the same institute. He's worked in photovoltaics, solid state hydrogen storage, perovskite oxides catalyzation of fuel cells, nano-coatings and other energy-related projects.
IntroductionThe area of wetting plays a major role in many engineering processes, such as oil recovery, printing, and coating. During the last decade, research work has been increasing to study wetting properties of metallic... [ view full abstract ]
Introduction
The area of wetting plays a major role in many engineering processes, such as oil recovery, printing, and coating. During the last decade, research work has been increasing to study wetting properties of metallic materials, due to their major impact in applications like self-cleaning and nanofluids. Determination of hydrophobicity and hydrophilicity of surfaces involves the measurement of contact angle when a coated surface and liquid interact. This contact angle is affected by several parameters such as liquid’s surface energy, roughness of the surface, type of material of the surface, etc.
This work investigates the change in contact angle of droplet of deionized water (DIW) when interact with different metallic surfaces (Fe, Ni, Au, Pd, and Cr) fabricated at the nanoscale (Figure 1). Moreover, the surfaces will be exposed to thermal environment to study its effect on the contact angle for the studied materials.
Experimental
Thin films of Fe, Ni, Au, Pd, and Cr were deposited on Si substrates by electron-beam physical vapor deposition (e-beam PVD) technique under low pressure < 10-6 Torr. Deposited film thickness of all studied materials was 4 nm. Experimental measurements of the contact angle of DIW droplets dispensed on the deposited metallic thin films on silicon substrate was carried out by Optical Contact Angle system (OCA 100 Dataphysics).
Results and Analysis
Results show that the contact angle depends strongly on the type deposited material. 4 nm gold surface has revealed the highest contact angle 97.6o closer to be hydrophobic surface as shown in Figure 2. On the other hand, the iron 4 nm surface has shown a contact angle of 70.2o which is considered a hydrophilic surface. Moreover, contact angle values of DIW with Ni, Pd, and Cr surfaces are falling in between gold and iron values, which are considered to be hydrophilic surfaces (Figure 3). These findings contribute to understanding the role of metallic thin films of different types on surface wettability.
Nanotechnology for environment and energy , Nanofabrication, nanoprocesing & nanomanufacturing
