Influence of surface texture directionality and roughness on wettability, sliding angle, contact angle hysteresis, and lubricant entrapment capability

Icing on insulators may cause flashover or even blackout accidents in the power transmission system. However, there are few anti-icing techniques for insulators which consume energy or manpower. Considering the water repelling property, the superhydrophobic surface is introduced for anti-icing of insulators. Among the icing forms, the glaze icing owns the highest density, strongest adhesion, and greatest risk to the power transmission system but lacks researches on superhydrophobic surface. In this paper, superhydrophobic surfaces with contact angle of 166.4°, contact angle hysteresis of 0.9°, and sliding angle of less than 1° are prepared by nanoparticle filling combined with etching method. The coated glass slide and glass insulator showed excellent anti-icing performance in the glaze icing test at −5°C. The superhydrophobicity and anti-icing property of the coatings benefit from the low surface energy and hierarchical rough structure containing micron scale pits and nanoscale coralloid bulges supported by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) characterization.

Download Full-text

A SUPERHYDROPHOBIC COATING ON TITANIUM ALLOYS BY SIMPLE CHEMICAL ETCHING

Surface Review and Letters ◽

10.1142/s0218625x2150027x ◽

2021 ◽

pp. 2150027

Author(s):

YUFENG ZHANG ◽

GUOLIANG CHEN ◽

YAMING WANG ◽

YONGCHUN ZOU

Keyword(s):

Contact Angle ◽

Titanium Alloy ◽

Electrochemical Impedance ◽

Contact Angle Hysteresis ◽

Manufacturing Strategy ◽

Superhydrophobic Coating ◽

Sliding Angle ◽

The Hierarchical Structure ◽

Silane Modification ◽

Self Cleaning

In the present study, a scalable-manufactured and environmental-friendly method was proposed to fabricate the superhydrophobic coating on titanium alloy. The hierarchical binary surface structures were obtained by hydrothermal treatment of titanium alloy with oxalic acid and sodium hydroxide solutions successively. The hierarchical structure surfaces after fluoroalkyl-silane modification possessed a maximum contact angle of 158.7° and a sliding angle of 4.3°. The low contact angle hysteresis surface can lead to efficient self-cleaning performance, which was confirmed by the bounce and roll off of water droplet on the surface. Furthermore, the anticorrosion behaviors of the superhydrophobic coating in 3.5[Formula: see text]wt.% NaCl solution was evaluated by the electrochemical impedance spectroscopy (EIS). It was found that the superhydrophobic coating can maintain its superhydrophobic state (150°) within 48 h, thereby effectively preventing the corrosive medium from penetrating into the coating. This simple yet fast anti-corrosion/self-cleaning superhydrophobic coating manufacturing strategy will enlighten its potential application in the engineering fields.

Download Full-text

Micro-Nanostructured Silicone Rubber Surfaces Using Compression Molding

Materials Science Forum ◽

10.4028/www.scientific.net/msf.941.1802 ◽

2018 ◽

Vol 941 ◽

pp. 1802-1807 ◽

Cited By ~ 2

Author(s):

Khosrow Maghsoudi ◽

Gelareh Momen ◽

Reza Jafari ◽

Masoud Farzaneh ◽

Tony Carreira

Keyword(s):

Surface Roughness ◽

Contact Angle ◽

Silicone Rubber ◽

Surface Characterization ◽

Contact Angle Hysteresis ◽

Compression Molding ◽

Sliding Angle ◽

Water Contact ◽

Superhydrophobic Property ◽

Aluminum Surfaces

A facile method is introduced for production of micro-nanostructured silicone rubber surfaces by means of direct replication using a compression molding system. The fabricated samples possessing surface roughness display water contact angle of more than 160o and contact angle hysteresis (CAH) and sliding angle of less than 5o. Such low surface wettability of silicone specimens verifies the induced superhydrophobic property. Chemically etched aluminum surfaces could work excellently as templates whose patterns were replicated on the rubber surfaces successfully. Various etching conditions were examined. Surface characterization techniques revealed the presence of micro-nanostructures on the produced silicone surfaces.

Download Full-text

T1602-1-1 Effect of microstructure on sliding angle and contact-angle-hysteresis and their formulation

The proceedings of the JSME annual meeting ◽

10.1299/jsmemecjo.2010.8.0_215 ◽

2010 ◽

Vol 2010.8 (0) ◽

pp. 215-216

Author(s):

Takeshi Takada ◽

Nobuyuki Moronuki ◽

Arata Kaneko

Keyword(s):

Contact Angle ◽

Contact Angle Hysteresis ◽

Sliding Angle ◽

Effect Of Microstructure

Download Full-text

Multifunctional aluminium surfaces – Laser-structured micropatterns with ice-repellent, superhydrophobic and easy-to-clean properties

MATEC Web of Conferences ◽

10.1051/matecconf/202032604005 ◽

2020 ◽

Vol 326 ◽

pp. 04005

Author(s):

Stephan Milles ◽

Marcos Soldera ◽

Bogdan Voisiat ◽

Andrés Fabián Lasagni

Keyword(s):

Contact Angle ◽

Contact Angle Hysteresis ◽

Contact Angles ◽

Pure Aluminium ◽

Sliding Angle ◽

Water Contact ◽

Static Contact ◽

Direct Laser ◽

Periodic Microstructures ◽

Time Required

In this work, the fabrication of multifunctional periodic microstructures on pure aluminium is presented. Three different geometries were fabricated with feature sizes ranging between 7 µm and 50 µm by using laser-based microstructuring methods. In detail, nanosecond pulsed direct laser writing and picosecond pulsed direct laser interference patterning were used with infrared laser radiation. The wetting characteristics of these structures were investigated performing static water contact angle measurements as well as by measuring the contact angle hysteresis and the sliding angle. The final wetting results show constant static contact angles above 150°, permitting the water droplets to roll off the substrate as well as collecting contamination at the same time. This self-cleaning effect led to a reduction of up to 94% of the spread of 1 µm sized manganese oxide particles. In addition, the freezing time required for droplets laying on the patterned surfaces was increased nearly by 300% at a temperature of 20 °C below zero. Finally, the results are compared to finite element simulations of heat transfer.

Download Full-text

Dynamic Contact Angle and Corrosion Test Measurements on Cu and CuO-Stearic Acid Modifications on Steel Surfaces

Indonesian Journal of Computing, Engineering and Design (IJoCED) ◽

10.35806/ijoced.v2i1.103 ◽

2020 ◽

Vol 2 (1) ◽

pp. 49

Author(s):

I Setiawan ◽

S R Trisnanto ◽

I O Suryani

Keyword(s):

Contact Angle ◽

Corrosion Rate ◽

Stearic Acid ◽

Corrosion Test ◽

Contact Angle Hysteresis ◽

Dynamic Contact Angle ◽

Dynamic Contact ◽

Coated Steel ◽

Sliding Angle ◽

Bare Steel

In this study, a copper (Cu) coated steel surface’s dynamic con-tact angle and corrosion rate was compared to the bare steel and stearic acid modified surfaces. Various steps of surface treatment have been performed including electrodeposition of Cu, CuO formation from H2O2 immersion with stearic acid modi-fication to obtain dynamic contact angle and the corrosion rate data. The Cu-coated steel’s dynamic contact angle was increased as it implied the surface after Cu treatment was more hydro-philic than the bare steel, with sliding angle and contact angle hysteresis of 54.9o ± 2.39o and 39.5o ± 1.91o, respectively. How-ever, corrosion test measurements by using a mass loss method to quantify the corrosion rate showed that Cu-coated steel and stearic acid-modified Cu-O coated steel had no remarkable dif-ference in corrosion rate. It was found that the Cu-coated steel and stearic acid-modified Cu-O coated steel had corrosion rate eight times slower than the bare surface.

Download Full-text