scholarly journals Assembly Mechanism and the Morphological Analysis of the Robust Superhydrophobic Surface

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 472 ◽  
Author(s):  
Doeun Kim ◽  
Arun Sasidharanpillai ◽  
Ki Hoon Yun ◽  
Younki Lee ◽  
Dong-Jin Yun ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Superhydrophobic Surface ◽  
Spray Coating ◽  
Silica Nanoparticle ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Thin Layers ◽  
Superhydrophobic Surfaces ◽  
Assembly Mechanism ◽  
Developed Surface

Robust superhydrophobic surfaces are fabricated on different substrates by a scalable spray coating process. The developed superhydrophobic surface consists of thin layers of surface functionalized silica nanoparticle (SiO2) bound to the substrate by acrylate-polyurethane (PU) binder. The influence of the SiO2/PU ratio on the superhydrophobicity, and the robustness of the developed surface, is systematically analyzed. The optimized SiO2/PU ratio for prepared superhydrophobic surfaces is obtained between 0.9 and 1.2. The mechanism which yields superhydrophobicity to the surface is deduced for the first time with the help of scanning electron microscopy and profilometer. The effect of mechanical abrasion on the surface roughness and superhydrophobicity are analyzed by using profilometer and contact angle measurement, respectively. Finally, it is concluded that the binder plays a key role in controlling the surface roughness and superhydrophobicity through the capillary mechanism. Additionally, the reason for the reduction in performance is also discussed with respect to the morphology variation.

scholarly journals EFFECT OF SILICA COATING IN ACRYLIC ARTIFICIAL TEETH ON SURFACE ROUGHNESS, CONTACT ANGLE, AND GROWTH OF STREPTOCOCCUS MUTANS

2021 ◽  
Vol 8 (2) ◽  
pp. 106
Author(s):  
Adella Syvia Maharani ◽  
Pramudya Aditama ◽  
Murti Indrastuti ◽  
Suparyono Saleh
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Streptococcus Mutans ◽  
Bacterial Adhesion ◽  
Acrylic Resin ◽  
Silica Coating ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Group I ◽  
Artificial Teeth

ABSTRACTBackground: Acrylic resin artificial teeth is easily to have bacterial adhesion. It is necessary to perform a treatment on that surface, in order to reduce bacterial adhesion. This study aimed to reveal the effect of silica coating in acrylic resin artificial teeth on surface roughness, contact angle measurement, and the growth of Streptococcus mutans.Method: The study was conducted on two groups (n=16) of disk-shaped acrylic resin artificial teeth with a diameter of 10 mm and thickness of 2 mm. A 2% silica coating material was obtained by diluting 2 g silica nanoparticles on 100 ml of ethanol. Surface roughness, contact angle measurement, and the growth of Streptococcus mutans was measured using surface roughness measuring instrument, camera digital, and colony counter. The data obtained were then analyzed using T-test (p<0.05).Result: The results showed that the surface roughness and contact angle measurement in group I (0.29±0.08 μm); (79,49º ± 10,88º) was higher than group II (0.17±0.05 μm); (34,77º±0,05º). The growth of Streptococcus mutans in group I was also higher (32.28±3.75 CFU/ml) than group II (24.83±3.47 CFU/ml). Conclusion: The study concluded that there is an effect of silica coating on surface roughness, contact angle measurement, and the growth of Streptococcus mutans in acrylic resin artificial teeth.

scholarly journals Fabrication of Robust Superhydrophobic Surfaces with Dual-Curing Siloxane Resin and Controlled Dispersion of Nanoparticles

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1420
Author(s):  
Hyeran Kim ◽  
Kibeom Nam ◽  
Dong Yun Lee
Keyword(s):  
Superhydrophobic Surface ◽  
Spray Coating ◽  
Surface Hydrophobicity ◽  
Superhydrophobic Surfaces ◽  
Simple Method ◽  
Coated Materials ◽  
Two Factors ◽  
Coating Method ◽  
Dual Curing ◽  
Dispersion Of Nanoparticles

We developed a simple method for the fabrication of superhydrophobic surfaces on various substrates using spray coating. The fabrication method started with the blending of a modified hydrophobic siloxane binder, silica nanoparticles, and a volatile solvent by sonication. The mixture was spray-coated on various surfaces such as slide glass, paper, metal and fabric, forming a rough surface comprising silica particles dispersed in a hydrophobic binder. Surface hydrophobicity was affected by the surface energy of the binder and the degree of roughness. Therefore, we realized a superhydrophobic surface by controlling these two factors. The hydrophobicity of the siloxane binder was determined by the treatment of fluorine silane; the roughness was controlled by the amount of coated materials and sonication time. Thus, using the spray coating method, we obtained a superhydrophobic surface that was mechanically durable, thermally stable, and chemically resistant.

scholarly journals Preparation of Superhydrophobic Teflon® AF 1600 Sub-Micron Fibers and Yarns Using the Forcespinningtm Technique

2013 ◽  
Vol 8 (4) ◽  
pp. 155892501300800 ◽  
Author(s):  
Yatinkumar Rane ◽  
Aleksey Altecor ◽  
Nelson S. Bell ◽  
Karen Lozano
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Average Diameter ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Sem Analysis ◽  
Fiber Formation ◽  
Excellent Thermal Stability ◽  
Wetting Properties

Superhydrophobic materials combined with manufacturing processes that can increase surface roughness of the material, offer an opportunity to effectively control wetting properties. Rapid formation of Teflon® AF (TAF) fibrous mats with sub-micron fiber diameter using the Forcespinning™ technique is presented. The fiber formation technique is based on the use of centrifugal forces. SEM analysis shows uniform formation of TAF 1600 fibers with average diameter of 362±58nm. Contact angle measurement confirms the superhydrophobic nature of the mats with contact angles as high as 169° ± 3° and rolling angles of 2°. TAF 1600 mats were forcespun at a rate of 1gr/min. The relationship between the contact angle and hierarchical surface roughness of the TAF mat is also discussed. TAF yarns were also manufactured and characterized. Yarns with diameters of 156 microns withstood 17.5 MPa of engineering stress with a Young's modulus of 348 MPa in the elastic region and excellent thermal stability.

scholarly journals Tulip-Shaped Pattern Imprinting for Omni-Phobic Surfaces Using Partially Cured Photopolymer

2021 ◽  
Vol 11 (4) ◽  
pp. 1747
Author(s):  
Su Hyun Choi ◽  
Do Hyeog Kim ◽  
Seonjun Kim ◽  
Woo Young Kim ◽  
Seok Kim ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Uv Light ◽  
Uv Curing ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Imprint Lithography ◽  
Chemical Surface ◽  
Shaped Pattern ◽  
Nano Imprint

Functional films with hydrophobic, oleophobic, anti-fouling, anti-icing, anti-bacterial and low reflectance properties can be produced by patterning nano- or micro-structures on films via nano imprint lithography. Here, an omni-phobic surface showing both hydrophobicity and oleophobicity was obtained without chemical surface treatment by increasing the surface roughness and deforming the pattern morphology using only nano imprint lithography and the oxygen-inhibited curing properties of polyurethane acrylate (PUA) resin. A tulip-shaped pattern imprinting process was designed in which microscale patterns were fabricated using a porous polydimethylsiloxane (PDMS) mold with high oxygen transmission. During ultraviolet (UV) curing, a curing inhibiting layer was formed by reaction with oxygen. Next, a PDMS pad was used for the pressurized curing of the curing inhibition layer to modify the micro scale structures. Finally, final curing of the deformed pattern was performed using ultra high-power UV light. The deformation of the pattern into tulip-like shapes with increased surface roughness was confirmed by microscopy, and contact angle measurement was performed to confirm omni-phobicity. The final cured imprinted samples showed water and oil contact angles reaching 169.2° and 115°, respectively; thus, the omni-phobic surface could be demonstrated by a tulip-shaped pattern imprinting process.

Study on the Factors Affecting the Hydrophobic Property of Silica Membranes

2014 ◽  
Vol 1058 ◽  
pp. 74-77
Author(s):  
Ya Jun Liu ◽  
Qi Wei ◽  
Wei Ying Chen ◽  
Qun Yan Li
Keyword(s):  
Surface Roughness ◽  
Carbon Chain ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Hydrophobic Property ◽  
Water Contact ◽  
Factors Affecting ◽  
Silica Membranes ◽  
Atomic Force ◽  
Alkyl Groups

Various hydrophobic groups were used to modify the silica membranes by the co-hydrolysis and condensation of 1,2-bis(triethoxysilyl)ethane and alkylsilanes. The hydrophobic property and surface roughness of silica membranes were characterized by water contact angle measurement and atomic force microscope, respectively. The results show that the hydrophobic property of modified silica membranes increases with increasing concentration of alkylsilane in the mixture, increasing surface roughness and increasing length of carbon chain in the alkyl groups.

Surface Roughness and Droplet Contact Angle Measurement of Various Orthodontic Bonding Cements

1993 ◽  
Vol 20 (4) ◽  
pp. 297-305 ◽  
Author(s):  
C. O'Kane ◽  
R. G. Oliver ◽  
R. E. Blunden
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Glass Ionomer Cement ◽  
Surface Characteristics ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Bacterial Attachment ◽  
Before And After ◽  
Orthodontic Bonding

Surface characteristics that are considered important for bacterial attachment to thirteen orthodontic bonding composite cements and one glass ionomer cement were examined in vitro before and after toothbrush abrasion. The surface roughness and contact angle measurements were found to be statistically significantly different between the materials, both before and after brushing, and there were also statistically significant changes within materials after brushing. There were low correlation coefficients between surface roughness and contact angle for both pre-and post-brushed materials.

scholarly journals Correlation between Contact Angle and Surface Roughness of Silicon Carbide Wafers

2021 ◽  
Author(s):  
Jung Gon Kim ◽  
Woo Sik Yoo ◽  
Woo Yeon Kim ◽  
Won Jae Lee
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Surface Polarity ◽  
Force Microscopy ◽  
Water Drops ◽  
The Difference ◽  
Sic Wafer

Abstract Two-inch diameter 6H-SiC wafers were sliced from a SiC ingot and the wafers were ground and polished using different diamond slurries (1 m and 0.1 m in particles size) to investigate their dependence on wetting on surface roughness (Ra) and polarity using precisely dispensed de-ionized (DI) water drops. The Ra of the Si-face (0001) SiC wafer, after grinding and polishing, was 5.6 and 1.6 nm, respectively, as measured by atomic force microscopy (AFM). For C-face (000-1) SiC wafers, the Ra was 7.2 nm after grinding and 3.3 nm after polishing. The average contact angle measurement of the SiC wafers after final polishing showed clear differences between surface polarity; the contact angle for the Si-face (0001) was ~7o greater than that for the C-face (000-1). The difference in contact angles between the Si-face (0001) and the C-face (000-1) tends to increase as the reduction of surface roughness approaches the final stage of polishing. The uniformity of Raman peak intensity in the folded transverse optical phonon band at ~780 cm-1 in scanned areas correlated well with the surface roughness measured by AFM. The contact angle measurement can be used as a convenient surface polarity and surface roughness testing technique for SiC wafers.

Effect of Morphology of Nano-Structured Surfaces on Anti-Icing Performance

2020 ◽  
Vol 12 (6) ◽  
Author(s):  
Siyan Yang ◽  
Tingting Hao ◽  
Mucan Liu ◽  
Xingtong Yu ◽  
Xuehu Ma
Keyword(s):  
Surface Roughness ◽  
Surface Morphology ◽  
Surface Temperature ◽  
Superhydrophobic Surface ◽  
Hydrophobic Surface ◽  
Water Repellency ◽  
Superhydrophobic Surfaces ◽  
Structured Surfaces ◽  
Nano Size ◽  
Morphology Parameters

Abstract Droplets bouncing off cold surfaces before being frozen is one way to achieve anti-icing, in which process superhydrophobic surfaces have been proven to play an important role. By using template-assisted method, three types of copper nanowired superhydrophobic surfaces (NSHSs) with mainly two morphologies (aggregated and upright) are fabricated. CuO nanograssed superhydrophobic surface (SHS) and copper smooth hydrophobic surface (HS) are also fabricated as a comparison. Compared with smooth HS and nanograssed SHS, all NSHSs exhibit better performance in repelling impacting droplet. In detail, on three types of NSHSs with temperatures ranging from 20 °C to −20 °C, impacting droplets can totally rebound. Among the three types, nanowires aggregated most exhibit the best water-repellency performance. The different performances among the five surfaces are due to surface temperature and surface morphology parameters, including micro/nano-size and surface roughness.

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