Change of surface morphology, permeate flux, surface roughness and water contact angle for membranes with similar physicochemical characteristics (except surface roughness) during microfiltration

2017 ◽  
Vol 187 ◽  
pp. 274-284 ◽  
Author(s):  
Sahng Hyuck Woo ◽  
Byoung Ryul Min ◽  
Ju Sung Lee
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Morphology ◽  
Water Contact Angle ◽  
Physicochemical Characteristics ◽  
Permeate Flux ◽  
Water Contact ◽  
Flux Surface

Addition of Cellulose Nanofibers to Control Surface Roughness for Hydrophobic Ceramic Coatings

2021 ◽  
Vol 21 (8) ◽  
pp. 4492-4497
Author(s):  
Eun Ae Shin ◽  
Gye Hyeon Kim ◽  
Jeyoung Jung ◽  
Sang Bong Lee ◽  
Chang Kee Lee
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Energy ◽  
Water Contact Angle ◽  
Ceramic Coating ◽  
Cellulose Nanofibers ◽  
Ceramic Coatings ◽  
Coating Material ◽  
Textured Surface ◽  
Water Contact

Hydrophobic ceramic coatings are used for a variety of applications. Generally, hydrophobic coating surfaces are obtained by reducing the surface energy of the coating material or by forming a highly textured surface. Reducing the surface energy of the coating material requires additional costs and processing and changes the surface properties of the ceramic coating. In this study, we introduce a simple method to improve the hydrophobicity of ceramic coatings by implementing a textured surface without chemical modification of the surface. The ceramic coating solution was first prepared by adding cellulose nanofibers (CNFs) and then applied to a polypropylene (PP) substrate. The surface roughness increased as the amount of added CNFs increased, increasing the water contact angle of the surface. When the amount of CNFs added was corresponding to 10% of the solid content, the surface roughness average of the area was 43.8 μm. This is an increase of approximately 140% from 3.1 μm (the value of the surface roughness of the surface without added CNFs). In addition, the water contact angle of the coating with added CNF increased to 145.0°, which was 46% higher than that without the CNFs. The hydrophobicity of ceramic coatings with added CNFs was better because of changes in the surface topography. After coating and drying, the CNFs randomly accumulated inside the ceramic coating layer, forming a textured surface. Thus, hydrophobicity was improved by implementing a rugged ceramic surface without revealing the surface of the CNFs inside the ceramic layer.

Preparation of Hydrophobic Nylon Fabric

2016 ◽  
Vol 11 (1) ◽  
pp. 155892501601100
Author(s):  
Jinmei Du ◽  
Lulu Zhang ◽  
Jing Dong ◽  
Ying Li ◽  
Changhai Xu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Energy ◽  
Water Contact Angle ◽  
Sem Images ◽  
Water Contact ◽  
Carboxyl Content ◽  
Factors Affecting ◽  
Nylon Fabric ◽  
Butanetetracarboxylic Acid

Surface roughness and surface energy are two important factors affecting the hydrophobicity of nylon fabric. In this study, nylon fabric was treated for hydrophobicity with tetrabutyltitanate (TBT) and octadecylamine (OA) which were respectively responsible for increasing surface roughness and reducing surface energy. In order to enhance the hydrophobicity, In order to further enhance hydrophobicity by increasing available reactive sites, 1,2,3,4–butanetetracarboxylic acid (BTCA) was applied as a pretreatment to the nylon fabric It was found that the carboxyl content of nylon was increased by the BTCA pretreatment. SEM images showed that the TBT treatment produced small particles on nylon fabric which made surface rough. The water contact angle of nylon fabric treated with BTCA, TBT and OA was measured to be 134°, which was much greater than the water contact angle of nylon fabric treated only with OA. This indicated that the surface roughness resulting from the TBT treatment played an important role in improving hydrophobicity of the treated nylon fabric. The resistance to water penetration and the repellency of water spray of nylon fabric treated with BTCA, TBT and OA were respectively measured to be 27.64 mbar and 85 out of 100.

Improved Hydrophobicity of Silicon Dioxide Integrated Zinc-Tellurite Glass Surface

2017 ◽  
Vol 268 ◽  
pp. 87-91
Author(s):  
Syarinie Azmi ◽  
Ramli Arifin ◽  
Sib Krishna Ghoshal
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Surface Energy ◽  
Water Contact Angle ◽  
Glass Surface ◽  
Tellurite Glass ◽  
Hydrophobic Surfaces ◽  
Water Contact ◽  
Host Matrix ◽  
The Impact

Economically viable and maintenance free glass surfaces with improved hydrophobicity are highly demanding in the recent nanotechnology era. Deposition of pollutants and dirt on glass surface that not only causes visual obscurity but also damages the cultural heritages are still to be researched intensely. It is documented that excellent hydrophobic surfaces (with contact angle greater than 90o) can be achieved by controlling the surface wettability, where liquid droplets remain spherical on such surfaces. Selection of materials and the preparation method play a significant role towards such accomplishments. Stirred by this idea, we explored the feasibility of fabricating super-hydrophobic tellurite glass systems by facilely varying the compositions of different constituents. Highly transparent and thermally stable ternary tellurite glass system with chemical composition of (80-x)TeO2 – xSiO2 – 20ZnO, where x = 0.00 to 0.20 mol% are synthesized via conventional melt-quenching method. Samples are characterized using Atomic Force Microscopy (AFM) and contact angle measurements. The impact of SiO2 concentrations variation on the surface roughness, surface energy, and hydrophobic properties are inspected. Glass surface roughness as much as 9.885 nm is attained. The optimal value of water contact angle is discerned to be 101.02° for 0.1 mol% of SiO2 incorporation into the amorphous tellurite host matrix. Besides, the surface energy revealed an inverse proportionality to the water contact angle. This achieved contact angle (greater than 90°) makes this hydrophobic glass surface beneficial for diverse applications. It is established that the present glass composition may be prospective for the development of super-hydrophobic surfaces.

scholarly journals Measurements of surface free energy as a tool to asses the effect of varnishing and printing of the paper substrates

2020 ◽  
Author(s):  
Zuzanna Żołek-Tryznowska ◽  
◽  
Marta Więcek ◽  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Free Energy ◽  
Surface Free Energy ◽  
Water Contact Angle ◽  
Water Contact ◽  
Human Eye ◽  
Varnish Layer ◽  
Energy Determination ◽  
Paper Substrates

Nowadays, printing products might be finished in various ways. Varnishing process is one of the most popular finishing method which gives various effect, such as mate, glossy etc. However, the varnish layer applied on the paper is very thin, therefore it can be invisible to the naked human eye. The aim of this work was to use contact angle measurement and surface free energy determination as a tool to assess the effect of printing and varnishing process of paper materials. We have used various tools in order to analyses the changes of surface: surface roughness, gloss, water contact angle absorption and surface free energy determination. Those tools were used in order to confirm whether the print has been covered with varnish or not. In this work six various paper substrates were used (glossy, coated and un-coated papers). The printing and varnishing was performed in laboratory conditions using flexographic water-based printing and waterbased varnish. Samples were prepared as follows: paper with ink coating, paper with varnish coating and paper with ink layer and varnish layer on the top. The surface roughness was determinated of all samples and compared. The surface roughness changes were observed for pure paper, overprinted and overvarnished. Next, the gloss of samples prior and after printing and varnishing was measured. The gloss of the samples increases when they are printed or varnished, what is related with properties of ink and varnish. Also, the thickness of ink and varnish layers was determinated. The thickness of the samples increases when the number of layers increases. Finally, the water contact angle was measured and surface free energy was calculated with Owens-Wendt method. Our results reveal the possibility of using various tools in order to confirm the performance of varnishing of the prints. The printing with various colors is always seen by the naked human eye. On the other hand, the varnish layer might be not visible. However, such a comparison is not possible if we do not have the pure paper substrates prior printing or varnish.

The Influences of Surface Roughness on the Water Contact Angle for Coated Substrate with F-DLC

2018 ◽  
Vol 764 ◽  
pp. 68-77 ◽  
Author(s):  
Xiu Ting Wei ◽  
Wei Liang Shi ◽  
Zhi Yong Li ◽  
Zhi Gang Wang ◽  
Xiao Long Wu ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
The Other ◽  
Water Contact ◽  
Abrasive Resistance ◽  
Coated Substrate ◽  
Deposition Technology

Hydrophobicity improvement of DLC can be achieved by adding fluorine element usually. However, higher F content may affect the other performance of DLC seriously, such as strength and abrasive resistance. Plasma enhanced chemical vapor deposition technology were employed to prepare F-DLC on the surface of steel (S35C) substrate in condition of 20mass% of F. Experimental results demonstrated that roughness significant increase in the coating substrate has contributed to improve hydrophobicity. In the range of 0~200nm for the roughness, the contact angle is influenced by the surface energy and the surface roughness; Ra>200nm, the influence of roughness on the water contact angle is gradually becoming the leading. And Ra=1300nm, water contact angle is 104°.

Anodic Oxide Film Formed on Ti-6Al-4V at a Low Current Density in Monocalciumphosphate Monohydrate (MCPM) Electrolyte and its Biocompatibility

2014 ◽  
Vol 608 ◽  
pp. 212-217
Author(s):  
Sutthima Sriprasertsuk ◽  
Phanawan Whangdee ◽  
Supatra Jinawath ◽  
Pasutha Thunyakitpisal ◽  
Dujreutai Pongkao Kashima
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Oxide Film ◽  
Water Contact Angle ◽  
Current Density ◽  
Chemical Species ◽  
Anodic Oxide ◽  
Anodic Oxide Film ◽  
Key Factors ◽  
Water Contact

Anodic oxide film on titanium alloy (Ti-6Al-4V) substrate was prepared by anodization. The reaction was done by applying low current densities from 0.25 to 2 mA/cm2 for 30 minutes using monocalciumphosphate monohydrate (MCPM) solution as an electrolyte. Essential parameters which affected to the formation of anodic oxide film were studied. The properties of the anodic oxide film would be optimized when the parameters were appropriately controlled. Increasing of the current density and the concentration of MCPM electrolyte could promote hydrophilicity and surface roughness of the film. After anodization, the anodic oxide film formed at 2 mA/cm2 in 1M MCPM showed the best hydrophilicity (lowest water contact angle) and the film formed at 0.25 mA/cm2 in 0.5M MCPM showed the lowest hydrophilicity (highest water contact angle). XPS analyses confirmed that the chemical species of as-anodized film formed at 2 mA/cm2 in 1M MCPM changed. Ti2p spectra scarcely changed while the O1s spectra significantly changed due to the presence of chemisorbed water and Ti-OH formed during anodization. The SEM micrographs also revealed the biocompatibility from the growth of the cementoblast cell on anodized surface. It was indicated that anodization using MCPM as an electrolyte at 2 mA/cm2 in 1M MCPM could modify the surface roughness and chemical species and that both are likely to be crucial key factors for enhancing of hydrophilicity of as-anodized film which would enhance the biocompatibility of Ti-6Al-4V as a result.

scholarly journals Fabrication of a Simultaneous Highly Transparent and Highly Hydrophobic Fibrous Films

2021 ◽  
Vol 11 (12) ◽  
pp. 5565
Author(s):  
Doo-Hyeb Youn ◽  
Kyu-Sung Lee ◽  
Sun-Kyu Jung ◽  
Mangu Kang
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Water Contact Angle ◽  
Electrospun Fiber ◽  
Contact Angles ◽  
Light Transmittance ◽  
Electrospun Fibers ◽  
Water Contact ◽  
Aligned Fibers ◽  
Highly Hydrophobic

This paper discusses the fabrication and characterization of electrospun nanofiber scaffolds made of polystyrene (PS). The scaffolds were characterized in terms of their basis material molecular weight, fiber diameter distribution, contact angles, contact angle hysteresis, and transmittance. We propose an aligned electrospun fiber scaffold using an alignment tool (alignment jig) for the fabrication of highly hydrophobic (θW > 125°) and highly transparent (T > 80.0%) films. We fabricated the alignment jig to align the electrospun fibers parallel to each other. The correlation between the water contact angles and surface roughness of the aligned electrospun fibers was investigated. We found that the water contact angle increased as the surface roughness was increased. Therefore, the hydrophobic properties of the aligned electrospun fibers were enhanced by increasing the surface roughness. With the change in the electrospinning mode to produce aligned fibers rather than randomly distributed fibers, the transmittance of the aligned electrospun fibers increased. The increase in the porous area, leading to better light transmittance in comparison to randomly distributed light scattering through the aligned electrospun fibers increased with the fibers. Through the above investigation of electrospinning parameters, we obtained the simultaneous transparent (>80%) and hydrophobic (θW > 140°) electrospun fiber scaffold. The aligned electrospun fibers of PS had a maximum transmittance of 91.8% at the electrospinning time of 10 s. The water contact angle (WCA) of the aligned electrospun fibers increased from 77° to 141° as the deposition time increased from 10 s to 40 s. The aligned fibers deposited at 40 s showed highly hydrophobic characteristics (θW > 140°).

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