Abstract:Large-scale molecular dynamic simulations were conducted to study anisotropic wettability on one-dimensional (1D) nanopatterned surfaces. Hexadecane (C 16 H 34 ) and decane (C 10 H 22 ) nanodroplets were used as wetting liquids. Initially, surfaces with various intrinsic wettability (oleophobic and oleophilic) were produced using surface lattice size as a control parameter. These surfaces were subsequently patterned with 1D grooves of different sizes, and their anisotropic wettability was examined. The results… Show more
“…This occurs due to the fact that groove walls function as pinning points, providing additional support with the surface tension. As a result, the contact angles were larger when observing the droplet from the direction of the grooves (Park et al, 2021). It should be mentioned here that not only the wettability of a surface could affect the biofilm formation, but also the biofilm formation could impact the wetting characteristics of a surface (Recupido et al, 2020;Castigliano et al, 2021;Kampouraki et al, 2022;Recupido et al, 2022;Recupido et al, 2023).…”
The prolonged duration of future manned space missions conceals potential threats associated with microbial contamination. Such closed environments are susceptible to formation of complex biofilm communities, where microorganisms can thrive and further evolve. The objective of this study was to evaluate the impact of surface type, surface treatment and shear stress on biofilm formation in water facilities. To that aim, the ability of Pseudomonas fluorescens SBW25 to adhere on three space applications related materials, including passivated (SS) and both passivated and electropolished (SSEP) stainless steel, as well as Ti-6Al-4V (Ti) alloy was studied under stagnant and shear stress conditions after 24 h of exposure. Results indicated that surface type strongly affects bacterial adhesion under the same conditions. Surface coverage during static experiments was in the following order: SS > Ti > SSEP, while SS exhibited a fourfold surface coverage compared to SSEP highlighting the significance of surface treatment. Moreover, SS and Ti stimulate the formation of several microcolonies and their growth. On the other hand, the application of shear stress diminished bacterial attachment to the studied materials, the degree of which relied on the material type. In this case, bacterial settlement on SS and Ti was dependent on the surface texture, implying that surface roughness may also play an important role in cell adhesion under shear conditions. Furthermore, the metallic surfaces did not hinder bacterial attachment when silver ions were previously deposited on their surface. The deposition that occurs on metallic surfaces when in contact with water disinfected with silver ions, for example, during space missions, highlights its impact on the loss of disinfection capacity of silver ions.
“…This occurs due to the fact that groove walls function as pinning points, providing additional support with the surface tension. As a result, the contact angles were larger when observing the droplet from the direction of the grooves (Park et al, 2021). It should be mentioned here that not only the wettability of a surface could affect the biofilm formation, but also the biofilm formation could impact the wetting characteristics of a surface (Recupido et al, 2020;Castigliano et al, 2021;Kampouraki et al, 2022;Recupido et al, 2022;Recupido et al, 2023).…”
The prolonged duration of future manned space missions conceals potential threats associated with microbial contamination. Such closed environments are susceptible to formation of complex biofilm communities, where microorganisms can thrive and further evolve. The objective of this study was to evaluate the impact of surface type, surface treatment and shear stress on biofilm formation in water facilities. To that aim, the ability of Pseudomonas fluorescens SBW25 to adhere on three space applications related materials, including passivated (SS) and both passivated and electropolished (SSEP) stainless steel, as well as Ti-6Al-4V (Ti) alloy was studied under stagnant and shear stress conditions after 24 h of exposure. Results indicated that surface type strongly affects bacterial adhesion under the same conditions. Surface coverage during static experiments was in the following order: SS > Ti > SSEP, while SS exhibited a fourfold surface coverage compared to SSEP highlighting the significance of surface treatment. Moreover, SS and Ti stimulate the formation of several microcolonies and their growth. On the other hand, the application of shear stress diminished bacterial attachment to the studied materials, the degree of which relied on the material type. In this case, bacterial settlement on SS and Ti was dependent on the surface texture, implying that surface roughness may also play an important role in cell adhesion under shear conditions. Furthermore, the metallic surfaces did not hinder bacterial attachment when silver ions were previously deposited on their surface. The deposition that occurs on metallic surfaces when in contact with water disinfected with silver ions, for example, during space missions, highlights its impact on the loss of disinfection capacity of silver ions.
“…34,35 Nanoconical surface topology is significant to align LCs in their preferred dimensional orientations and therefor accelerates or weakens the electrical switch of LCs by modified surface anchoring. 36,37 In this research, the alignment and electro-optical switch of LCs that are sandwiched between hybrid thin layers in the twist nematic (TN) mode and electrically controller birefringence (ECB) mode were investigated to see how LCs were modulated by nanotips. Alignment of LCs in the TN mode was characterized and captured using POM as shown in Figure 5.…”
Liquid crystals (LCs) are an active area of interest
for electro-optical
devices, and the alignment of LCs has emerged as an extremely essential
issue for LC devices. Evidence suggests that the surface topology
of alignment layers plays a key role in both tuning the tilt angles
and modulating the switching of LCs. Herein, nanotips are constructed
by self-assembly of two different two-dimensional (2D) nanoflakes
in PI hybrid alignment layers to modulate the switching of LCs. Both
MoS2 nanotips and Ti3C2T
x
MXene nanotips were observed on hybrid thin layers,
but MoS2 nanotips are much thinner and taller. The hybrid
thin layers are highly transparent, and the nanotips penetrating the
hybrid layers roughened the surface but moderately declined the surface
energy. LCs are strongly anchored on hybrid alignment layers, and
the nanotips were found to topologically hinder the in-plane switching
of LCs and hence accelerate the rewriting speed of optical data. Besides
the accelerated optical rewriting speed, the surface plasmon–polariton
(SPP) of nanoflakes also substantially boosted the external electric
field to switch LCs and hence remarkably diminished the operating
voltage and likewise sufficiently shortened the response time. In
particular, the optical rewriting time of LCs that homogeneously aligned
on hybrid alignment layers with 0.5% MoS2 nanoflakes doping
has been deduced to as short as 43.36 s, which is a decrease of 37.81%
compared to that of PI alignment layers cell; LCs can be electrically
driven to switch optical data at 2.51 V and return to their original
alignment state within 24.142 ms. These results signify the promising
applications of hybrid thin layers for both traditional LC devices
and optical rewritable LC devices.
“…Aluminum sheets (AA 6061, 25 mm × 75 mm × 1.5 mm, from McMaster-CARR) were selected for testing as a commonly used material in the industry. Numerous studies have investigated methods for modifying the wettability of solid substrates by changing the chemical and/or morphological characteristics of the surface. − In this study, we developed an efficient and feasible method to create a patterned surface with a singular tunable wettability contrast for various impact conditions. This contrast was achieved by coating two types of self-assembled monolayers (SAM), using a dipping method with trichloro-octylsilane (OT, CH 3 (CH 2 ) 7 SiCl 3 , 97%, from Sigma-Aldrich) and trichloro-octadecylsilane (OD, CH 3 (CH 2 ) 17 SiCl 3 , 85%, from Fisher Scientific).…”
While the simplest outcome of a normal impact on a flat stationary solid surface is radially symmetric spreading, it is important to note that asymmetric spreading can intrinsically occur with a tangential velocity along the surface. However, no previous attempt has been made to restore the symmetry of a lamella that intrinsically spreads asymmetrically. Adjusting the lamella's asymmetric shape to a symmetric one is achieved in this work by varying wettability to affect the receding velocity of the contact line, according to the Taylor-Culick theory. Here we theoretically and practically show how restoring the symmetry can be achieved. Theoretically we built a framework to map the needed receding velocity at every given point of the contact line to allow for symmetry to be restored, and then this framework was applied to generate a wetting map that shows how at each local the wettability of the surface needs to be defined. Simulated results confirmed the effectiveness of our framework and identified the envelope of its applicability. Next, to apply the idea experimentally, the wetting map was transformed to a single wettability contrast area dubbed the "patch". Experimental results showed the effectiveness of the patch design in correcting the asymmetric spreading lamella for water droplets impacting a surface for the following Weber number conditions: We n ≤ 300, We t ≤ 300, and 0.51 ≤ We n /We t ≤ 2.04.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.