scholarly journals What Is the Value of Water Contact Angle on Silicon?

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1554 ◽  
Author(s):  
Paweł Bryk ◽  
Emil Korczeniewski ◽  
Grzegorz S. Szymański ◽  
Piotr Kowalczyk ◽  
Konrad Terpiłowski ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Md Simulations ◽  
Surface Cleaning ◽  
Sio2 Layer ◽  
Water Contact ◽  
Pure Silicon ◽  
Wetting Properties ◽  
Cleaning Methods

Silicon is a widely applied material and the wetting of silicon surface is an important phenomenon. However, contradictions in the literature appear considering the value of the water contact angle (WCA). The purpose of this study is to present a holistic experimental and theoretical approach to the WCA determination. To do this, we checked the chemical composition of the silicon (1,0,0) surface by using the X-ray photoelectron spectroscopy (XPS) method, and next this surface was purified using different cleaning methods. As it was proved that airborne hydrocarbons change a solid wetting properties the WCA values were measured in hydrocarbons atmosphere. Next, molecular dynamics (MD) simulations were performed to determine the mechanism of wetting in this atmosphere and to propose the force field parameters for silica wetting simulation. It is concluded that the best method of surface cleaning is the solvent-reinforced de Gennes method, and the WCA value of silicon covered by SiO2 layer is equal to 20.7° (at room temperature). MD simulation results show that the mechanism of pure silicon wetting is similar to that reported for graphene, and the mechanism of silicon covered by SiO2 layer wetting is similar to this observed recently for a MOF.

scholarly journals Superhydrophobic organosilicon-based coating system by a novel ultravoilet-curable method

2017 ◽  
Vol 7 ◽  
pp. 184798041770279 ◽  
Author(s):  
Baojiang Liu ◽  
Taizhou Tian ◽  
Jinlong Yao ◽  
Changgen Huang ◽  
Wenjun Tang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Silica Nanoparticles ◽  
Water Contact Angle ◽  
Cotton Fabric ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Water Repellent ◽  
Step Method ◽  
Water Contact

A robust superhydrophobic organosilica sol-gel-based coating on a cotton fabric substrate was successfully fabricated via a cost-effective one-step method. The coating was prepared by modification of silica nanoparticles with siloxane having long alkyl chain that allow to reduce surface energy. The coating on cotton fabric exhibited water contact angle of 151.6°. The surface morphology was evaluated by scanning electron microscopy, and surface chemical composition was measured with X-ray photoelectron spectroscopy. Results showed the enhanced superhydrophobicity that was attributed to the synergistic effect of roughness created by the random distribution of silica nanoparticles and the low surface energy imparted of long-chain alkane siloxane. In addition, the coating also showed excellent durability against washing treatments. Even after washed for 30 times, the specimen still had a water contact angle of 130°, indicating an obvious water-repellent property. With this outstanding property, the robust superhydrophobic coating exhibited a prospective application in textiles and plastics.

The Study of Immobilization Thermal-Sensitive Hydrogel onto ePTFE Film Use the Cold Plasma and Photo-Grafting Technique

2006 ◽  
Vol 15-17 ◽  
pp. 187-192 ◽  
Author(s):  
Ko Shao Chen ◽  
Su Chen Chen ◽  
Yi Chun Yeh ◽  
Wei Cheng Lien ◽  
Hong Ru Lin ◽  
...  
Keyword(s):  
Contact Angle ◽  
Acetic Acid ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Cold Plasma ◽  
Plasma Deposition ◽  
Plasma Technology ◽  
Water Contact ◽  
X Ray ◽  
Grafting Technique

Expanded polytetrafluoroethylene (ePTFE) is a bioinert material. To improve the ePTFE film biocompatibility, the cold plasma technology was used with acetic acid as monomer to deposit onto ePTFE film and then (N-isopropylacrylamide) was grafted onto the surface by photo-grafting. The characteristics of the surface were evaluated with X-ray photoelectron spectroscopy (XPS), FTIR and water contact angle. It was found that the contact angle of water on the untreated ePTFE significantly decrease from125° to 72° after ePTFE film being treated with acetic acid plasma deposition treatment. Due to the hydrophilicity of poly(N-isopropylacrylamide), the contact angle of water on the ePTFE-g-NIPAAm approached to 0°.

Grafting Sulfoammonium Zwitterionic Brushes onto Polycarbonateurethane Surface to Improve Hemocompatibility

2011 ◽  
Vol 306-307 ◽  
pp. 1631-1634 ◽  
Author(s):  
Ya Kai Feng ◽  
Da Zhi Yang ◽  
Hai Yang Zhao ◽  
Jin Tang Guo ◽  
Qing Liang Chen ◽  
...  
Keyword(s):  
Contact Angle ◽  
Fourier Transform ◽  
Physical Properties ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Potential Application ◽  
Platelet Adhesion ◽  
Fourier Transform Infrared ◽  
Water Contact ◽  
X Ray

Poly(3-dimethyl(methacryloyloxyethyl)ammonium propane sulfonate) (poly(DMAPS)) zwitterionic brushes were grafted onto the polycarbonateurethane (PCU) surface to improve its hydrophilicity and hemocompatibility by Ultraviolet (UV) polymerization. Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and water contact angle were used to characterize the chemical and physical properties of the modified PCU surface. DMAPS-grafted PCU films showed significantly high hydrophilicity owing to the high hydrophilic poly(DMAPS) zwitterionic brushes. The cytotoxicity tests revealed the sulfoammonium zwitterionic brushes modified PCU film had good cytocompatibility. In addition, the hemocompatibility of the modified PCU films was evaluated by hemolytic tests and platelet adhesion tests. The PCU films modified with zwitterionic brushes had a lower hemolytic index, showed effective resistance to platelet adhesion. Due to the fact that sulfoammonium zwitterionic brushes can improve the hemocompatibility of the PCU surface, this gives rise to its potential application as blood-contacting materials or devices.

scholarly journals Germination of Phaseolus vulgaris L. Seeds after a Short Treatment with a Powerful RF Plasma

2021 ◽  
Vol 22 (13) ◽  
pp. 6672
Author(s):  
Nina Recek ◽  
Matej Holc ◽  
Alenka Vesel ◽  
Rok Zaplotnik ◽  
Peter Gselman ◽  
...  
Keyword(s):  
Contact Angle ◽  
Phaseolus Vulgaris ◽  
Plasma Treatment ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Rf Plasma ◽  
Phaseolus Vulgaris L ◽  
Short Treatment ◽  
Water Contact ◽  
Radicle Growth

Seeds of common bean (Phaseolus vulgaris L.), of the Etna variety, were treated with low-pressure oxygen plasma sustained by an inductively coupled radiofrequency discharge in the H-mode for a few seconds. The high-intensity treatment improved seed health in regard to fungal contamination. Additionally, it increased the wettability of the bean seeds by altering surface chemistry, as established by X-ray photoelectron spectroscopy, and increasing surface roughness, as seen with a scanning electron microscope. The water contact angle at the seed surface dropped to immeasurably low values after a second of plasma treatment. Hydrophobic recovery within a month returned those values to no more than half of the original water contact angle, even for beans treated for the shortest time (0.5 s). Increased wettability resulted in accelerated water uptake. The treatment increased the bean radicle length, which is useful for seedling establishment in the field. These findings confirm that even a brief plasma treatment is a useful technique for the disinfection and stimulation of radicle growth. The technique is scalable to large systems due to the short treatment times.

Preparation and Characterization of Plasma-Treated Porous Poly(glycerol sebacate) Scaffolds

2013 ◽  
Vol 747 ◽  
pp. 182-185
Author(s):  
Tharinee Theerathanagorn ◽  
Boonlom Thavornyutikarn ◽  
Wanida Janvikul
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Average Molecular Weight ◽  
Sebacic Acid ◽  
Angle Measurement ◽  
Porous Scaffolds ◽  
Hydroxyl Groups ◽  
Condensation Polymerization ◽  
Water Contact

In this study, poly (glycerol sebacate) (PGS) was initially synthesized via condensation polymerization of glycerol and sebacic acid at equimolar ratio (1:1) at 130°C for 24 h. The number average molecular weight (Mn) of the resulting polymer determined by gel permeation chromatography (GPC) was about 2800 g/mol. Porous PGS scaffolds were subsequently prepared by a particle-leaching technique. NaCl was added into the polymer at 60-90% w/w; the mixtures were cured in Teflon molds at 140°C for 16 h. The porous scaffolds were further subjected to surface treatment with low pressure oxygen plasma to increase surface carboxyl and hydroxyl groups and thereby enhance hydrophilicity of PGS scaffold surface. The surface morphology and wettability of both untreated PGS and plasma-treated PGS scaffolds were comparatively determined by scanning electron microscopy (SEM) and water contact angle measurement, respectively. A considerable decrease in water contact angle was observed on the PGS scaffolds after the plasma treatment. The surface chemistry, mechanical strength and degree of swelling of the PGS scaffolds were also assessed by X-ray photoelectron spectroscopy (XPS), dynamic mechanical analysis (DMA) and swelling measurement, respectively.

Grafting Biomimetic Phospholipid Zwitterionic Brushes onto Polycarbonateurethane for Improving Hemocompatibility

2011 ◽  
Vol 306-307 ◽  
pp. 3-6
Author(s):  
Hai Yang Zhao ◽  
Ya Kai Feng ◽  
Da Zhi Yang ◽  
Jin Tang Guo ◽  
Qing Liang Chen ◽  
...  
Keyword(s):  
Contact Angle ◽  
Fourier Transform ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Potential Application ◽  
Platelet Adhesion ◽  
Material Surface ◽  
Adhesion Test ◽  
Water Contact ◽  
X Ray

In order to improve the hemocompatibility of polycarbonateurethane (PCU), the biomimetic phosphorylcholine (PC) group was introduced onto material surface. Brush structure having PC groups was formed by ultraviolet (UV) initiated polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) to improve the hydrophilicity and hemocompatibility of PCU surfaces. Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electrical microscopy (SEM) and water contact angle were used to characterize the chemical and physical properties of the modified PCU surfaces. Compared with original PCU, the PC-grafted PCU surfaces showed significantly high hydrophilicity as indicating by low water contact angle. The hemocompatibility of the PC-grafted PCU surfaces was evaluated by platelet adhesion test. The PCU surfaces modified with phosphorylcholine zwitterionic brushes showed effective resistance to platelet adhesion and high hemocompatibility. These PC-grafted PCU materials will have potential application as blood-contacting materials or devices due to their good mechanical and hemocompatible properties.

Fabrication of superhydrophobic cotton fabrics through wrapping silica with plasma-induced grafting polymerization

2017 ◽  
Vol 89 (3) ◽  
pp. 401-410 ◽  
Author(s):  
Yongqiang Li ◽  
Chao Zou ◽  
Jianzhong Shao ◽  
Ya’nan Li
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Cotton Fabric ◽  
Photoelectron Spectroscopy ◽  
Contact Angle Measurement ◽  
Cotton Fabrics ◽  
Angle Measurement ◽  
Water Contact ◽  
Washing Durability ◽  
Before And After

Cotton fabric is commonly used in daily life, but it is easily wetted and contaminated by liquid. Herein, we present a simple and environmentally friendly plasma technology for hydrophobic modification of cotton fabric. In order to endow superhydrophobicity to cotton fabric, helium plasma inducing graft polymerization of 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane (D4Vi) was utilized to wrap SiO2 particles on cotton fabrics. Cotton fabrics were successively dipped in silica sol and D4Vi, then treated by plasma. Cotton fabrics before and after modification were characterized by using field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and water contact angle measurement. The experimental results showed that the cotton-SiO2-D4Vi consisted of nanoscale SiO2 protrusions and low-surface-energy film polymerized by D4Vi. In addition, the one wrapped SiO2 of 161 nm presented excellent hydrophobicity, washing durability, and repellency toward different types of liquids with a water contact angle of 152°.

scholarly journals Wetting Properties of the CO2–Water–Calcite System via Molecular Simulations: Shape and Size Effects

2019 ◽  
Author(s):  
Alessandro Silvestri ◽  
Evren Ataman ◽  
Akin Budi ◽  
Susan Stipp ◽  
Julian D Gale ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Water Droplet ◽  
Aqueous Fluid ◽  
Water Model ◽  
Correct Prediction ◽  
Mineral Surfaces ◽  
Water Contact ◽  
Local Conditions ◽  
Wetting Properties

<p>Assessment of the risks and environmental impacts of carbon geosequestration requires knowledge about the wetting behavior of mineral surfaces in the presence of CO<sub>2</sub> and the pore fluids. In this context, the interfacial tension (IFT) between CO<sub>2</sub> and the aqueous fluid and the contact angle, theta, with the pore mineral surfaces are the two key parameters that control the capillary pressure in the pores of the candidate host rock. Knowledge of these two parameters and their dependence on the local conditions of pressure, temperature and salinity is essential for the correct prediction of structural and residual trapping. We have performed classical molecular dynamics simulations to predict the CO<sub>2</sub>–water IFT and the CO<sub>2</sub>–water–calcite contact angle. The IFT results are consistent with previous simulations, where simple point charge water models have been shown to underestimate the water surface tension, thus affecting the simulated IFT values. When combined with the EPM2 CO<sub>2</sub> model, the SPC/Fw water model indeed underestimates the IFT in the low pressure region at all temperatures studied. On the other hand, at high pressure and low temperature, the IFT is overestimated by ~5 mN/m. Literature data regarding the water contact angle on calcite are contradictory. Using our new set of force field parameters, we performed NVT simulations at 323 K and 20 MPa to calculate the contact angle of a water droplet on the calcite {10.4} surface in a CO<sub>2</sub> atmosphere. We performed simulations for both spherical and cylindrical droplet configurations for different initial radii, to study the size dependence of the water contact angle on calcite in the presence of CO<sub>2</sub>. Our results suggest that the contact angle of a cylindrical water droplet on calcite {10.4}, in the presence of CO<sub>2</sub>, is independent of droplet size, for droplets with a radius of 50 Å or more. On the contrary, spherical droplets make a contact angle that is strongly influenced by their size. At the largest size explored in this study, both spherical and cylindrical droplets converge to the same contact angle, 38 degrees, indicating that calcite is strongly wetted by water.</p>

Preparation of BiOI Photocatalysts with Controllable Wettability and Their Enhanced Catalytic Degradation of 17α-ethinylestradiol

NANO ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. 2050150
Author(s):  
Sifeng Zhang ◽  
Lulu Wang ◽  
Ziguang Zheng ◽  
Yunrui Hei ◽  
Luting Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Removal Rate ◽  
Chemical Properties ◽  
Water Contact ◽  
X Ray ◽  
Photocatalytic Performances

In this study, BiOI was successfully synthesized using a hydrothermal method and then modified using hexamethyldisiloxane (HMDS) and polydimethylsiloxane (PDMS), respectively, to achieve a controllable water contact angle (WCA) for these materials. The physical and chemical properties of the modified BiOI were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) method, UV–Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared (FTIR) spectroscopy and water contact angle (WCA) techniques. Compared with the unmodified BiOI, HMDS- and PDMS-modified BiOI had higher photocatalytic activities for 17[Formula: see text]-ethinylestradiol (EE2) under visible light irradiation for 28 min after reacting in dark for 30 min. When BiOI was modified using HMDS and PDMS, the WCA increased. When the WCA of HMDS- and PDMS-modified BiOI was controlled in the range of 25.3–32.7[Formula: see text] and 38.1–78.5[Formula: see text], respectively, better photocatalytic performances were achieved. When the WCA of modified BiOI was 29.7[Formula: see text] (1.00[Formula: see text]mL HMDS) and 47.8[Formula: see text] (0.20[Formula: see text]mL PDMS), the best photocatalytic performances were achieved with EE2 removal rate of 98.85% and 98.72%, respectively, however, the removal rate of the unmodified BiOI was 85.01%. The reaction rate constants of BiOI (1.00[Formula: see text]mL HMDS) and BiOI (0.20[Formula: see text]mL PDMS) were 2.33 and 2.15 times higher than the unmodified BiOI, respectively. The improved catalytic performances of modified BiOI could be attributed to the synergistic effect of the controlled wettability of BiOI and functional groups on the surface of photocatalysts.

Wettability Control of Gold Surfaces Modified with Benzenethiol Derivatives: Water Contact Angle and Thermal Stability

2016 ◽  
Vol 16 (4) ◽  
pp. 3295-3300 ◽  
Author(s):  
Shingo Tatara ◽  
Yasutaka Kuzumoto ◽  
Masatoshi Kitamura
Keyword(s):  
Thermal Stability ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Water Contact ◽  
Wide Range ◽  
Water Wettability ◽  
Modified Surface ◽  
Surface Modified ◽  
Activation Energy Of Desorption

The water wettability of Au surfaces has been controlled using various benzenethiol derivatives including 4-methylbenzenethiol, pentafluorobenzenethiol, 4-fluorobenzenethiol, 4-methoxybenzenethiol, 4-nitrobenzenethiol, and 4-hydroxybenzenethiol. The water contact angle of the Au surface modified with the benzenethiol derivative was found to vary in the wide range of 30.9° to 88.3°. The contact angle of the modified Au films annealed was also measured in order to investigate their thermal stability. The change in the contact angle indicated that the modified surface is stable at temperatures below about 400 K. Meanwhile, the activation energy of desorption from the modified surface was estimated from the change in the contact angle. The modified Au surface was also examined using X-ray photoelectron spectroscopy.

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