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.

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 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.

Hydrophobisation of mechanical pulp fibres with sodium dodecyl sulphate functionalised layered double hydroxide particles

Holzforschung ◽  
2012 ◽  
Vol 66 (4) ◽  
Author(s):  
Carl Lange ◽  
Tom Lundin ◽  
Pedro Fardim
Keyword(s):  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Weight Ratio ◽  
Hydrophobic Surface ◽  
Fibre Surface ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Mechanical Pulp ◽  
Pulp Fibres

Abstract Hydrogen peroxide bleached spruce (Picea abies L.) made of thermo mechanical pulp (BTMP) fibres were modified with layered double hydroxides (LDH). The LDH particles were precipitated onto the BTMP fibre surfaces from aqueous solutions of urea and NaOH. The modified BTMP was further functionalised with sodium dodecyl sulphate (SDS) surfactant to produce pulp with hydrophobic character. The contact angle measurement with water on paper showed that the functionalisation with SDS was successful. The apparent contact angles varied in between the initial θ= 75° of the reference pulp up to θ= 135° of the SDS functionalised pulp. A hydrophobic surface was obtained already with 2.0% weight to weight ratio of SDS in pulp suspension. A high affinity between the LDH particles and the BTMP fibres was found as well. The investigated fibre modification route offers a new feasible tool in fibre surface treatment.

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.

Modification of PEDOT:PSS Surface by RGD Peptide

2019 ◽  
Vol 955 ◽  
pp. 68-73
Author(s):  
Šárka Tumová ◽  
Romana Malečková ◽  
Vojtěch Enev ◽  
Stanislav Stříteský ◽  
Jan Víteček ◽  
...  
Keyword(s):  
Contact Angle ◽  
Raman Spectroscopy ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Uv Light ◽  
Coupling Reaction ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Rgd Peptide ◽  
Novel Technique

In this paper, a novel technique for modification of PEDOT:PSS surface by the arginine-glycine-aspartic (RGD) acid, using a bifunctional photolinker sulfosuccinimidyl 6-(4’-azido-2’-nitrophenylamino) hexanoate (sulfo-SANPAH), is presented. The technique is based on the UV light initialized immobilization of the photolinker to the surface of the polymer and subsequent link of the RGD peptide to the photolinker via coupling reaction. The aim of this modification is the improvement of the biocompatibility and hydrophilicity of the polymer PEDOT:PSS. To confirm if the process of conjugation of RGD peptide to the surface of the polymer PEDOT:PSS was successful, the contact angle measurement, Fourier transform infrared spectroscopy, Raman spectroscopy and elemental analysis was performed. All of the obtained results indicate the conjugation of RGD peptide to the PEDOT:PSS surface was successful.

UV Nano-Imprint Lithography for Manufacturing Applications

2007 ◽  
Author(s):  
Jin Choi ◽  
S. V. Sreenivasan ◽  
Doug Resnick
Keyword(s):  
Uv Curing ◽  
Magnetic Storage ◽  
Imprint Lithography ◽  
Practical Applications ◽  
Drop On Demand ◽  
Defect Repair ◽  
Manufacturing Applications ◽  
Near Term ◽  
Layer Control ◽  
Nano Imprint

Researchers have demonstrated that imprint lithography techniques have remarkable replication resolution and can pattern sub-5nm structures. However, a fully capable lithography approach needs to address several challenges in order to be useful in nano-manufacturing applications. This paper presents the key technical challenges as well as the progress achieved to-date in these areas. A promising nanoimprint technique that has been previously discussed in the literature is a UV curing technique known as Step and Flash Imprint Lithography (S-FIL). In this article, a variant of the S-FIL process — known as drop-on-demand UV nano-imprint process — that addresses many of the key manufacturing challenges is discussed. This process has the ability to address challenges such as process repeatability in residual layer control, low defectivity, ability to fully automate the lithography process, nano-resolution alignment, and the ability to handle pattern density variations. All nano-imprint lithography techniques essentially replicate the patterns present in a master mold (or template). One of the demanding challenges is the creation of this template. Patterning, metrology, inspection, and defect repair issues relevant to template fabrication are discussed. Finally, with a brief discussion of near-term practical applications in the areas of photonics, magnetic storage, and CMOS devices is presented.

Wettability measurements on two sandstones: an experimental investigation before and after CO2 flooding

2020 ◽  
Vol 60 (1) ◽  
pp. 117
Author(s):  
Cut Aja Fauziah ◽  
Emad A. Al-Khdheeawi ◽  
Ahmed Barifcani ◽  
Stefan Iglauer
Keyword(s):  
Contact Angle ◽  
Co2 Storage ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Co2 Injection ◽  
Co2 Flooding ◽  
Berea Sandstone ◽  
Before And After ◽  
Carbon Dioxide Co2

Wettability of rock–fluid systems is an important for controlling the carbon dioxide (CO2) movement and the capacities of CO2 geological trapping mechanisms. Although contact angle measurement is considered a potentially scalable parameter for evaluation of the wettability characteristics, there are still large uncertainties associated with the contact angle measurement for CO2–brine–rock systems. Thus, this study experimentally examined the wettability, before and after flooding, of two different samples of sandstone: Berea and Bandera grey sandstones. For both samples, several sets of flooding of brine (5 wt % NaCl + 1 wt % KCl in deionised water), CO2-saturated (live) brine and supercritical CO2 were performed. The contact angle measurements were conducted for the CO2–sandstone system at two different reservoir pressures (10 and 15 MPa) and at a reservoir temperature of 323 K. The results showed that both the advancing and receding contact angles of the sandstone samples after flooding were higher than that measured before flooding (i.e. after CO2 injection the sandstones became more CO2-wet). Moreover, the Bandera grey samples had higher contact angles than Berea sandstone. Thus, we conclude that CO2 flooding altered the sandstone wettability to be more CO2-wet, and Berea sandstone had a higher CO2 storage capacity than Bandera grey sandstone.

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.

Hydrophobicity Enhancement of the Polyvinyl Alcohol/Rice Starch/Silk Fibroin Films by Glycerol

2013 ◽  
Vol 446-447 ◽  
pp. 360-365
Author(s):  
Pusita Kuchaiyaphum ◽  
Takeshi Yamauchi ◽  
Ruangsri Watanesk ◽  
Surasak Watanesk
Keyword(s):  
Contact Angle ◽  
Polyvinyl Alcohol ◽  
Silk Fibroin ◽  
Water Solubility ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Rice Starch ◽  
Water Contact ◽  
Degree Of Swelling

Eco-friendly films have been prepared using various biopolymers and their properties have been improved in order to meet the requirements for appropriate applications. However, the frequently encountered weakness of the properties of most biopolymer film is its water solubility. In this study, the polyvinyl alcohol/rice starch/silk fibroin (PVA/RS/SF) films were modified by the addition of glycerol aiming to increase the hydrophobicity of the films. Some properties of the modified films including water contact angle, degree of swelling and water solubility were compared with the unmodified PVA/RS/SF film. Results from the contact angle measurement showed that the films with glycerol could be transformed to be hydrophobic after soaking in ethanol medium. The increase in soaking time tends to increase the hydrophobicity of the films. However, at about 60 min soaking, the water contact angles on the films were quite constant with the values of about 107.9±5.2º comparing with 65.3±2.4º of the ethanol-untreated PVA/RS/SF films. In addition, the ethanol-treated glycerol-modified films also show higher degree of swelling with constant solubility and better mechanical properties.

Investigation of Amorphous Silicon-Carbon Films Deposited by Filtered Vacuum Cathodic Arc

2005 ◽  
Vol 23 ◽  
pp. 351-354
Author(s):  
P. Zhang ◽  
W.M. Tan ◽  
B.K. Tay
Keyword(s):  
Amorphous Silicon ◽  
Photoelectron Spectroscopy ◽  
Contact Angle Measurement ◽  
Peak Position ◽  
Carbon Films ◽  
Contact Angles ◽  
Angle Measurement ◽  
Vacuum Arc ◽  
Silicon Carbon ◽  
Filtered Cathodic Vacuum Arc

Amorphous silicon-carbon films have been successfully deposited by the filtered cathodic vacuum arc techniques. One set of films was deposited from varying silicon-carbon composition in the targets and another set of films was deposited at different various substrate bias voltages from 5 at.% silicon target. The properties of the film were investigated by using atomic force microscopy (AFM), Raman spectroscopy, x-ray photoelectron spectroscopy (XPS) and contact angle measurement. The first set of the samples exhibit atomic smooth surface morphology with RMS roughness below 0.26 nm. The silicon composition in the films determined by XPS varies from 0 to 61 at.%. The Raman results show that at low silicon composition, the G peak position of C-C bond shifts to a low wavenumber, that demonstrates the silicon atom predominantly substitutes for the carbon atom. As the silicon composition increase, the G peak disappeared and a strong broad peak corresponding to the amorphous silicon carbide cluster appears around 800 cm-1. For the second set, the Raman results show the ID/IG ratio increased from 0.24 to 0.67 with using the high bias voltages during the deposition. That indicates the disorder of C-C bond within the films increased. While, both the silicon concentration in the films and contact angles remain relatively constant with the change of bias voltage.

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