Wetting Behavior of Zirconia Nanotubes

In this work, we investigate the wettability of ZrO2 nanotubes (ZrNT) synthesized via electrochemical anodization of Zirconium. The ZrNT surface shows superhydrophilic behavior while the octadecylphosphonic acid (C18H37PO(OH)2) modified surface shows superhydrophobic behavior. We demonstrate that the wetting properties are independent of ZrO2 nanotube geometry and length.<br>

Wetting Behavior of Zirconia Nanotubes

In this work, we investigate the wettability of ZrO2 nanotubes (ZrNT) synthesized via electrochemical anodization of Zirconium. The ZrNT surface shows superhydrophilic behavior while the octadecylphosphonic acid (C18H37PO(OH)2) modified surface shows superhydrophobic behavior. We demonstrate that the wetting properties are independent of ZrO2 nanotube geometry and length.<br>

Wetting behavior of zirconia nanotubes

In this work, we investigate the wettability of octadecylphosphonic acid (OPA) self-assembled monolayer (SAM) modified ZrO2 nanotubes (ZrNT) of varied morphologies synthesized via electrochemical anodization of zirconium.

Protective films of stearic and octadecylphosphonic acid formed by spray coating

Spray coating formation of stearic and octadecylphosphonic acid films for corrosion protection of cupronickel alloy was studied in this work as a more practical alternative to widely studied dip-coating method. Protective properties of organic films formed under various experimental conditions were examined by electrochemical studies in 3% NaCl solution as a corrosive medium. Polarization resistance measurements as well as electro­chemical impedance spectroscopy were employed to follow in time the corrosion behaviour of cupronickel alloy modified by studied organic acids. It was found that among examined experimental parameters, time elapsed between two sprays and number of sprays have the strongest influence on the film stability and its protective properties. This study confirmed that it is possible to form by spray coating the films of stearic and octadecyl­phosphonic acid with protective properties that resemble to those of the films prepared by dip-coating method. Differences in corrosion behaviour of samples protected with stearic and octadecyl­phosphonic acid were attributed to difference in the bond strength between substrate and each organic acid. Studied samples were also examined by the scanning electron microscopy. Fourier transformed infrared spectroscopy studies showed that crystalline structure dominates in studied films, while contact angle measure­ments confirmed that modified cupronickel alloy surface exhibits hydrophobic properties.

Molecular Coverage Determines Sliding Wear Behavior of n-Octadecylphosphonic Acid Functionalized Cu–O Coated Steel Disks against Aluminum

The sliding wear behavior of Cu–O coated steel disks functionalized with n-octadecyl-phosphonic acids was evaluated against aluminum in ball-on-disk tribometer experiments. After 5 m of sliding the friction coefficient of the functionalized sample with maximum molecular coverage is ≤0.3 ± 0.1. Surfaces with lower coverage mitigate friction and wear as well exhibiting initially similar low friction coefficients but reveal the breakdown of lubrication for sliding distances <5 m. The length of the low friction sliding distance before breakdown scales with the coverage of n-octadecylphosphonic acids on the Cu–O surface. Coverage hence determines the tribological behavior of the functionalized surface against sliding aluminum. As the coverage is increased, detrimental asperity contacts between the rubbing surfaces are reduced.

Corrosion Protection by Octadecylphosphonic Acid in Flow Conditions

The aim of this work was to examine the influence of the flow rate of corrosive media on the stability of self-assembled films of octadecylphosphonic acid on copper-nickel alloy and stainless steel. The studies were conducted in river and seawater in a laboratory scale flow system. Corrosion behaviour of protected and unprotected alloys was examined by electrochemical techniques, electrochemical impedance spectroscopy, and polarization measurements. The results show that octadecylphosphonic acid films can efficiently protect copper-nickel and stainless steel from corrosion in flowing natural waters. The flow of corrosive media had the highest influence on the stability of films on CuNi in seawater, while in all other studied cases, the protective properties of ODPA film changed insignificantly with the change of the flow rate.