scholarly journals Facile Synthesis of Fluorinated Polysilazanes and Their Durable Icephobicity on Rough Al Surfaces

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 330
Author(s):  
Tien N. H. Lo ◽  
Sung Woo Hong ◽  
Ha Soo Hwang ◽  
In Park
Keyword(s):  
Acidic Solution ◽  
Freezing Temperature ◽  
High Water ◽  
Ice Nucleation ◽  
Coated Sample ◽  
Efficient Removal ◽  
Sliding Angle ◽  
Water Contact ◽  
Nano Structures ◽  
Coated Surface

Superhydrophobic Al surfaces with excellent durability and anti-icing properties were fabricated by coating dual-scale rough Al substrates with fluorinated polysilazane (FPSZ). Flat Al plates were etched using an acidic solution, followed by immersion in boiling water to generate hierarchical micro-nano structures on their surfaces. The FPSZ coatings were synthesized by grafting 1H,1H,2H,2H-perfluorodecyltrimethoxysilane (FAS-17), a fluoroalkyl silane), onto methylpolysilazane, an organopolysilazane (OPSZ) backbone. The high water contact angle (175°) and low sliding angle (1.6°) of the FPSZ-coated sample with an FAS-17 content of 17.3 wt% promoted the efficient removal of a frozen ice column with a low ice adhesion strength of 78 kPa at −20.0 °C (70% relative humidity), which was 4.3 times smaller than that of an OPSZ-coated surface. The FPSZ-coated Al surface suppressed ice nucleation, leading to a decrease in ice nucleation temperature from −19.5 to −21.9 °C and a delay in freezing time from 334 to 4914 s at −19.0 °C compared with the OPSZ-coated Al surface. Moreover, after 40 icing–melting cycles the freezing temperature of a water droplet on the FPSZ-coated Al surface remained unchanged, whereas that on the FAS-17-coated Al surface increased from −22.3 to −20.7 °C. Therefore, the durability of the polymeric FPSZ coating was superior to that of the FAS-17 monolayer coating.

scholarly journals Superhydrophobic Self-Assembled Silane Monolayers on Hierarchical 6082 Aluminum Alloy for Anti-Corrosion Applications

2020 ◽  
Vol 10 (8) ◽  
pp. 2656 ◽  
Author(s):  
Amani Khaskhoussi ◽  
Luigi Calabrese ◽  
Edoardo Proverbio
Keyword(s):  
Aluminum Alloy ◽  
Surface Energy ◽  
High Water ◽  
Dip Coating ◽  
Aluminum Surface ◽  
Sliding Angle ◽  
Water Contact ◽  
Electrochemical Tests ◽  
Self Assembled ◽  
6082 Aluminum Alloy

In this work, a two-stage methodology to design super-hydrophobic surfaces was proposed. The first step consists of creating a rough nano/micro-structure and the second step consists of reducing the surface energy using octadecyltrimethoxysilane. The surface roughening was realized by three different short-term pretreatments: (i) Boiling water, (ii) HNO3/HCl etching, or (iii) HF/HCl etching. Then, the surface energy was reduced by dip-coating in diluted solution of octadecyltrimethoxysilane to allow the formation of self-assembled silane monolayers on a 6082-T6 aluminum alloy surface. Super-hydrophobic aluminum surfaces were investigated by SEM-EDS, FTIR, profilometry, and contact and sliding angles measurements. The resulting surface morphologies by the three approaches were structured by a dual hierarchical nano/micro-roughness. The surface wettability varied with the applied roughening pretreatment. In particular, an extremely high water contact angle (around 180°) and low sliding angle (0°) were evidenced for the HF/HCl-etched silanized surface. The results of electrochemical tests demonstrate a remarkable enhancement of the aluminum alloy corrosion resistance through the proposed superhydrophobic surface modifications. Thus, the obtained results evidenced that the anti-wetting behavior of the aluminum surface can be optimized by coupling an appropriate roughening pretreatment with a self-assembled silane monolayer deposition (to reduce surface energy) for anticorrosion application.

scholarly journals Fabrication of Superhydrophobic Nanocomposite Coatings Using Polytetrafluoroethylene and Silica Nanoparticles

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Bharathibai J. Basu ◽  
V. Dinesh Kumar
Keyword(s):  
Cost Effective ◽  
High Water ◽  
Nanocomposite Coatings ◽  
Sliding Angle ◽  
Electron Microscopic ◽  
Water Contact ◽  
Superhydrophobic Coatings ◽  
Low Surface Energy ◽  
Hydrophobically Modified ◽  
Superhydrophobic Property

Superhydrophobic nanocomposite coatings were fabricated by incorporating hydrophobically modified silica (HMS) nanoparticles in polytetrafluoroethylene (PTFE) emulsion. Hydrophobicity of the coating was dependent on the concentration of HMS. Coatings containing optimum amounts of PTFE and HMS exhibited superhydrophobic property with high water contact angle (WCA) of 165∘ and low sliding angle <2∘. Scanning electron microscopic (SEM) studies have shown a binary surface topography composed of microbumps and nanoscale granules. The synergistic effect of the micro-nano-binary structure and low surface energy of PTFE was responsible for the superhydrophobicity of the coating. The method is simple and cost-effective and can be used for preparing self-cleaning superhydrophobic coatings on large areas of different kinds of substrates like glass, metal, and composites.

scholarly journals A Facile Modifier-free Approach to Fabricate Antistatic Superhydrophobic Composite Coatings with Remarkable Thermal Stability and Corrosion Resistance

2020 ◽  
Vol 17 (3) ◽  
pp. 421-435
Author(s):  
Xiang Liu ◽  
Dekun Zhang ◽  
Zhiguang Guo
Keyword(s):  
Thermal Stability ◽  
Low Cost ◽  
Composite Coatings ◽  
Spray Coating ◽  
High Water ◽  
Polyphenylene Sulfide ◽  
Superhydrophobic Surfaces ◽  
Superhydrophobic Coating ◽  
Sliding Angle ◽  
Water Contact

AbstractResearch on antistatic superhydrophobic surfaces has attracted widespread attention in some fields. However, in the application of superhydrophobic materials, fabricating stable and practical superhydrophobic surfaces through facile and low-cost approaches still faces considerable challenges. Herein, a polyphenylene sulfide (PPS)-based antistatic superhydrophobic composite coating with a high water contact angle (166°) and a low sliding angle (2°) was fabricated on a Q345 steel surface through a simple spray-coating method without any modifier. Furthermore, the as-prepared superhydrophobic coating also displayed excellent superhydrophobicity for water droplets at different pH values, as well as self-cleaning, anti-fouling and anti-icing properties. Importantly, the superhydrophobic coating still exhibited superhydrophobicity after calcination at 350 °C for 1 h, indicating its outstanding thermal stability. Excellent antistatic and anticorrosion properties were obtained on the prepared coating surface, which allows the coating to be applied under harsh conditions. Benefiting from the above characteristics, compared with the commercial coating, the as-obtained antistatic superhydrophobic coating may be applied more widely in related fields.

Facile Fabrication of Super-Hydrophobic Surfaces by Spray PTFE

2015 ◽  
Vol 645-646 ◽  
pp. 115-119
Author(s):  
Yang Wang ◽  
Hai Feng Zhang ◽  
Xiao Wei Liu
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
High Water ◽  
Water Repellent ◽  
Sliding Angle ◽  
Hydrophobic Property ◽  
Water Contact ◽  
Electro Deposition ◽  
Long Term Stability ◽  
Facile Fabrication

We have developed a combination of electro –deposition and spraying methods to prepare water-repellent tin oxide/ polytetrafluoroethylene(SnO2/PTFE) coating. The coating has a high water contact angle. The resulting porous and lowest surface energy hydrophobic groups (－CF3) has a water contact angle of 165° and a sliding angle of 7°, showing super-hydrophobic property. The coating with good adhesion on substrates and the long-term stability can be fabricated on various metal substrates.

scholarly journals Osseointegration Improvement of Co-Cr-Mo Alloy Produced by Additive Manufacturing

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 724
Author(s):  
Amilton Iatecola ◽  
Guilherme Arthur Longhitano ◽  
Luiz Henrique Martinez Antunes ◽  
André Luiz Jardini ◽  
Emilio de Castro Miguel ◽  
...  
Keyword(s):  
Surface Modification ◽  
Additive Manufacturing ◽  
Bone Ingrowth ◽  
Orthopedic Implants ◽  
Coated Sample ◽  
High Mechanical Strength ◽  
Coated Surface ◽  
Surface Modification Techniques ◽  
Almost All ◽  
Cobalt Base

Cobalt-base alloys (Co-Cr-Mo) are widely employed in dentistry and orthopedic implants due to their biocompatibility, high mechanical strength and wear resistance. The osseointegration of implants can be improved by surface modification techniques. However, complex geometries obtained by additive manufacturing (AM) limits the efficiency of mechanical-based surface modification techniques. Therefore, plasma immersion ion implantation (PIII) is the best alternative, creating nanotopography even in complex structures. In the present study, we report the osseointegration results in three conditions of the additively manufactured Co-Cr-Mo alloy: (i) as-built, (ii) after PIII, and (iii) coated with titanium (Ti) followed by PIII. The metallic samples were designed with a solid half and a porous half to observe the bone ingrowth in different surfaces. Our results revealed that all conditions presented cortical bone formation. The titanium-coated sample exhibited the best biomechanical results, which was attributed to the higher bone ingrowth percentage with almost all medullary canals filled with neoformed bone and the pores of the implant filled and surrounded by bone ingrowth. It was concluded that the metal alloys produced for AM are biocompatible and stimulate bone neoformation, especially when the Co-28Cr-6Mo alloy with a Ti-coated surface, nanostructured and anodized by PIII is used, whose technology has been shown to increase the osseointegration capacity of this implant.

scholarly journals Condensed-phase biogenic–anthropogenic interactions with implications for cold cloud formation

2017 ◽  
Vol 200 ◽  
pp. 165-194 ◽  
Author(s):  
Joseph C. Charnawskas ◽  
Peter A. Alpert ◽  
Andrew T. Lambe ◽  
Thomas Berkemeier ◽  
Rachel E. O’Brien ◽  
...  
Keyword(s):  
Freezing Temperature ◽  
Organic Aerosol ◽  
Ice Nucleation ◽  
Mixed Phase ◽  
Cloud Formation ◽  
Fossil Fuel Combustion ◽  
Soot Particles ◽  
Ice Nuclei ◽  
Deliquescence Relative Humidity ◽  
Homogeneous Freezing

Anthropogenic and biogenic gas emissions contribute to the formation of secondary organic aerosol (SOA). When present, soot particles from fossil fuel combustion can acquire a coating of SOA. We investigate SOA–soot biogenic–anthropogenic interactions and their impact on ice nucleation in relation to the particles’ organic phase state. SOA particles were generated from the OH oxidation of naphthalene, α-pinene, longifolene, or isoprene, with or without the presence of sulfate or soot particles. Corresponding particle glass transition (Tg) and full deliquescence relative humidity (FDRH) were estimated using a numerical diffusion model. Longifolene SOA particles are solid-like and all biogenic SOA sulfate mixtures exhibit a core–shell configuration (i.e.a sulfate-rich core coated with SOA). Biogenic SOA with or without sulfate formed ice at conditions expected for homogeneous ice nucleation, in agreement with respectiveTgand FDRH. α-pinene SOA coated soot particles nucleated ice above the homogeneous freezing temperature with soot acting as ice nuclei (IN). At lower temperatures the α-pinene SOA coating can be semisolid, inducing ice nucleation. Naphthalene SOA coated soot particles acted as ice nuclei above and below the homogeneous freezing limit, which can be explained by the presence of a highly viscous SOA phase. Our results suggest that biogenic SOA does not play a significant role in mixed-phase cloud formation and the presence of sulfate renders this even less likely. However, anthropogenic SOA may have an enhancing effect on cloud glaciation under mixed-phase and cirrus cloud conditions compared to biogenic SOA that dominate during pre-industrial times or in pristine areas.

scholarly journals Ice nucleation activity identified in some phytopathogenic Fusarium species

2005 ◽  
Vol 77 (2) ◽  
pp. 83-92 ◽  
Author(s):  
C. Richard ◽  
J.-G. Martin ◽  
S. Pouleur
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Species ◽  
Freezing Temperature ◽  
Ice Nucleation ◽  
Free Living ◽  
Factors Affecting ◽  
Pure Cultures ◽  
Nucleation Activity ◽  
Ice Nucleation Activity ◽  
Positive Controls

In order to know which species of Fusarium are ice nucleating and to determine the factors affecting their pathogenicity, ice nucleation activity (INA) was examined in Fusarium oxysporum, F. sporotrichioides, and F. tricinctum. Positive controls (lna+) used were F. acuminatum and F. avenaceum. The test for fungal INA was done with a simple and rapid tube nucleation assay. Twelve out of the 42 F. oxysporum isolates, and 8 out of 14 F. tricinctum isolates were lna+. No INA was detected in F sporotrichioides. In this test the threshold freezing temperature tended to increase with culture age, reaching a peak of -1°C in a few samples, which is as high as the warmest INA reported for bacteria, and higher than the INA detected in pure cultures of free-living fungi, lichen fungi, lichen algae and cyanobacteria. This is the first report of INA for F oxysporum.

Real-Time EM Look-Ahead Resistivity for Mapping of Oil/Water Contact While Drilling at Low Deviated Well, New Perspective for Mature Oil Fields Development: A Case Study Of Umm Gudair Field, Kuwait

2021 ◽  
Author(s):  
Nasser Faisal Al-Khalifa ◽  
Mohammed Farouk Hassan ◽  
Deepak Joshi ◽  
Asheshwar Tiwary ◽  
Ihsan Taufik Pasaribu ◽  
...  
Keyword(s):  
Water Saturation ◽  
High Water ◽  
Carbonate Reservoir ◽  
Water Contact ◽  
Saturation Zone ◽  
Look Ahead ◽  
Production History ◽  
Oil Water ◽  
High Water Cut ◽  
Water Cut

Abstract The Umm Gudair (UG) Field is a carbonate reservoir of West Kuwait with more than 57 years of production history. The average water cut of the field reached closed to 60 percent due to a long history of production and regulating drawdown in a different part of the field, consequentially undulating the current oil/water contact (COWC). As a result, there is high uncertainty of the current oil/water contact (COWC) that impacts the drilling strategy in the field. The typical approach used to develop the field in the lower part of carbonate is to drill deviated wells to original oil/water contact (OOWC) to know the saturation profile and later cement back up to above the high-water saturation zone and then perforate with standoff. This method has not shown encouraging results, and a high water cut presence remains. An innovative solution is required with a technology that can give a proactive approach while drilling to indicate approaching current oil/water contact and geo-stop drilling to give optimal standoff between the bit and the detected water contact (COWC). Recent development of electromagnetic (EM) look-ahead resistivity technology was considered and first implemented in the Umm Gudair (UG) Field. It is an electromagnetic-based signal that can detect the resistivity features ahead of the bit while drilling and enables proactive decisions to reduce drilling and geological or reservoir risks related to the well placement challenges.

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