Fabrication of the Superhydrophobic Surface Using SU-8 Photoresist With Black Silicon

2011 ◽  
Author(s):  
Sang Eon Lee ◽  
Dongjin Lee ◽  
Jin-Ha Kim ◽  
Kang Won Lee ◽  
Kwang-Cheol Lee ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Superhydrophobic Surface ◽  
Black Silicon ◽  
Geometrical Shape ◽  
Water Contact ◽  
Ion Etching ◽  
Lotus Leaf ◽  
Pdms Surface ◽  
Micro Structures

A novel change method of surface wettability using both micro- and nano-sized geometrical shape is presented in this paper. After the black silicon is formed in reactive ion etching, SU-8 mold is fabricated on top of the black silicon that has nano-sized holes. After the microfabrication of SU-8 photoresist mold, poly-dimethysiloxane (PDMS) is poured into the mold. As a result, the molded PDMS surface has both micro- and nano-sized structures, which is similar to lotus leaf. The diameter of cylindrical pillar micro structures ranges from 50 to 100 μm. The water contact angle of 150° is obtained on the molded PDMS surface with pillars diameter of 50 μm. The superhydrophobic surface made of micro- and nanostructures is straightforwardly formed, increasing water contact angle on the engineered surface.

Superhydrophobic Nanocrystalline Nickel Films Inspired by Lotus Leaf

2008 ◽  
Vol 1132 ◽  
Author(s):  
Mehdi Shafiei ◽  
Ahmet T. Alpas
Keyword(s):  
Contact Angle ◽  
Grain Size ◽  
Surface Structure ◽  
Water Contact Angle ◽  
Surface Texture ◽  
High Water ◽  
New Method ◽  
Water Contact ◽  
Lotus Leaf ◽  
Tip Radius

ABSTRACTA new method to fabricate superhydrophobic hard films is described. Surface texture of lotus leaf was replicated on an acetate film, on which a nanocrystalline (NC) Ni coating with a grain size of 30 ± 4 nm and a hardness of 4.42 GPa was electrodeposited. The surface texture consisted of conical protuberances with a height of 10.0 ± 2.0 0m and a tip radius of 2.5 ± 0.5 0m. An additional electrodeposition for 120 s and 300 s was used to locally modify the surface structure by depositing ‘Ni crowns' on the protuberances that increased their height to 14.0 ± 2.0 0m and their tip radius to 6.0 ± 0.5 0m. The modified structures were then treated with a perfluoropolyether (PFPE) solution, which provided a high water contact angle of 156°, i.e., comparable to the naturally superhydrophobic lotus leaf. The increased hydrophobicity as a result of surface structure and chemistry modifications was evident compared to a smooth NC Ni sample, which had a contact angle of 64°.

A Two-Step Method to Prepare Stable Superhydrophobic Surface on Steel Substrates

2012 ◽  
Vol 463-464 ◽  
pp. 349-353 ◽  
Author(s):  
Feng Guo ◽  
Xun Jia Su ◽  
Gen Liang Hou ◽  
Zhao Hui Liu ◽  
Hai Peng Jia
Keyword(s):  
Contact Angle ◽  
Superhydrophobic Surface ◽  
Low Cost ◽  
Superhydrophobic Surfaces ◽  
Step Method ◽  
Water Contact ◽  
Lotus Leaf ◽  
Nanoscale Particles ◽  
Steel Substrates

Superhydrophobic surfaces have been a hot topic during the last decade owing to their great potential in widely application. In this work, we report on a facile and low-cost two-step method to fabricate superhydrophobic surface on steel substrates. The as-obtained surface shows an interesting hierarchical structure composed of microscale flowerlike cluster and nanoscale particles, which is similar to that of a lotus leaf. After further modification with stearic acid, the resultant surface exhibits remarkable superhydrophobic properties. The water contact angle is as high as 155°. Moreover, the superhydrophobic properties are long-term stable.

scholarly journals A green approach of superhydrophobic surface fabrication on recycled high-density polyethylene using sodium chloride

2021 ◽  
Vol 2080 (1) ◽  
pp. 012004
Author(s):  
Muhammad Aidil Adz’ryl Nor Azizan ◽  
Muhammad Salihin Zakaria ◽  
Razif Muhammed Nordin ◽  
Khairul Anwar Abdul Halim ◽  
Bee Ying Lim ◽  
...  
Keyword(s):  
Contact Angle ◽  
Sodium Chloride ◽  
Surface Morphology ◽  
Water Contact Angle ◽  
High Density Polyethylene ◽  
Superhydrophobic Surface ◽  
High Density ◽  
Water Contact ◽  
Green Approach ◽  
Self Cleaning

Abstract In this work, the water-dissolved surface modifier method was introduced to recycled high-density polyethylene (rHDPE) matrix to fabricate green superhydrophobic surfaces. Surface cavities on rHDPE are formed by sodium chloride particles which can be readily rinsed off and reused. Water contact angle, self-cleaning properties, and surface morphology were characterized. By creating porosity onto the rHDPE matrix, the surface exhibits an excellent self-cleaning property with a water contact angle larger than 150°. Surface morphology reveals the porosity and roughness of the surface. In this fabricating process, no chemicals are used while rHDPE is selected for the purpose. Based on the findings, it is proven that the superhydrophobic surface can be fabricated with a simple yet green approach.

scholarly journals Fabrication and Characterization of Superhydrophobic Graphene/Titanium Dioxide Nanoparticles Composite

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 122
Author(s):  
Xun Hui Wu ◽  
Yoon Yee Then
Keyword(s):  
Contact Angle ◽  
Titanium Dioxide ◽  
Water Contact Angle ◽  
Medical Devices ◽  
Superhydrophobic Surface ◽  
Cost Effective ◽  
Tio2 Coating ◽  
Hybrid Nanoparticles ◽  
Poly Lactic Acid ◽  
Water Contact

Materials with superhydrophobic surfaces have received vast attention in various industries due to their valuable properties, such as their self-cleaning and antifouling effects. These promising superhydrophobic properties are taken into high priority, particularly for medical devices and applications. The development of an ideal superhydrophobic surface is a challenging task and is constantly progressing. Various strategies have been introduced; however, a minority of them are cost-effective. This work presents a facile fabrication of the superhydrophobic surface by using graphene and titanium dioxide (TiO2) nanoparticles. The graphene and TiO2 hybrid nanoparticles are dip-coated on a biodegradable thermoplastic poly(lactic acid) (PLA) substrate. The thermoplastic PLA is approved by the Food and Drug Administration (FDA), and is widely utilized in medical devices. The graphene/TiO2 coating is substantiated to transform the hydrophilic PLA film into superhydrophobic biomaterials that can help to reduce hazardous medical-device complications. The surface wettability of the graphene/TiO2 nanoparticle-coated PLA surface was evaluated by measuring the apparent water contact angle. The surface chemical composition and surface morphology were analyzed via Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The graphene/TiO2-coated PLA film achieved superhydrophobic properties by demonstrating a water contact angle greater than 150°. The water contact angle of the graphene/TiO2 coating increased along with the concentration of the nanoparticles and the ratio of TiO2 to graphene. Moreover, the graphene/TiO2 coating exhibited excellent durability, whereby the contact angle of the coated surface remained unchanged after water immersion for 24 h. The duration of the effectiveness of the superhydrophobic coating suggests its suitability for medical devices, for which a short duration of administration is involved. This study reports an easy-to-replicate and cost-effective method for fabricating superhydrophobic graphene/TiO2-coated surfaces, which additionally substantiates a potential solution for the manufacturing of biomaterials in the future.

An Effect of Viscosity of Coating Materials on Silicon Micro-Patterning Arrays for Superhydrophobic Surface

2010 ◽  
Vol 93-94 ◽  
pp. 447-450 ◽  
Author(s):  
N. Atthi ◽  
O. Nimittrakoolchai ◽  
Sitthisuntorn Supothina ◽  
J. Supadech ◽  
W. Jeamsaksiri ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Surface Property ◽  
Superhydrophobic Surface ◽  
Rough Surfaces ◽  
Coating Materials ◽  
Water Contact ◽  
Viscous Material ◽  
Micro Patterning

Two different viscous coating materials, which are Polydimethylsiloxane (PDMS) mixed with 10%wt of Dicumylperoxide (DCP), and Semifluorinate Silane (SFS), were applied to silicon micro-asperity. The cosine’s Young and viscosity of those coating materials are -0.3584,-0.3496 and 3.176x10-3, 1.339 x10-3 Pas, respectively. The rough surfaces with nine asperity shapes were studied. The results shown that, pillar shape has an effect on water contact angle (WCA): Stripe asperity cannot make the average WCA greater than 150. When consider the pillar asperity, the WCA falls between 152 and 157, which exhibits a superhydrophobic surface property. However, actual WCA of the micro-asperity coated with PDMS+10%wt of DCP is lower than that coated with SFS around 1 to 7. High viscous material makes the asperity size bigger than the design and decreases the WCA: the low viscous material is more suitable for coating on the asperities.

Fabrication of Stable Superhydrophobic Surface with Low Adhesion on Aluminum Foil

2014 ◽  
Vol 697 ◽  
pp. 80-84
Author(s):  
Yong Mei Xia ◽  
You Fa Zhang ◽  
Xin Quan Yu ◽  
Feng Chen
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Superhydrophobic Surface ◽  
Research Work ◽  
Aluminum Foil ◽  
Industrial Applications ◽  
Angle Measurement ◽  
Aluminum Surface ◽  
Chemical Compositions ◽  
Water Contact

Metal aluminum surface can be corroded easily in acid and alkaline environment. Inspired by the self-cleaning lotus leaf, the development of superhydrophobic metal surfaces to prevent metals from corroding is enjoying tremendous popularity amongst scientists and engineers. In this work, superhydrophobic surface was obtained on aluminum foils via a facile neutral sol solution immersion process and post-modification in ethanol solution of heptadecafluoro-1,1,2,2-tetradecyl trimethoxysilane (FAS-17) solution through a hydrothermal synthesis technique. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and water contact angle measurement are used to investigate the morphologies, microstructures, chemical compositions and wettability of the produced films on aluminum substrates. The results indicated that the superhydrophobic surface, configured of a rough labyrinth structure with convexity and notch, has robust hydrophobility, which had a static water contact angle of 165.6 ± 2.8° and a water roll-off angle of <1°, exhibited long-term durability and stability in air. The present research work provides a new strategy for the simple preparation superhydrophobic films on aluminum foil for practical industrial applications.

scholarly journals Fabrication and Corrosion Resistance of Superhydrophobic Hydroxide Zinc Carbonate Film on Aluminum Substrates

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jin Liang ◽  
Yunchu Hu ◽  
Yiqiang Wu ◽  
Hong Chen
Keyword(s):  
Contact Angle ◽  
Corrosion Resistance ◽  
Water Contact Angle ◽  
Superhydrophobic Surface ◽  
Aluminum Substrate ◽  
Morphological Observation ◽  
Water Contact ◽  
Zinc Carbonate ◽  
Eis Measurements ◽  
Aluminum Substrates

Superhydrophobic hydroxide zinc carbonate (HZC) films were fabricated on aluminum substrate through a convenient in situ deposition process. Firstly, HZC films with different morphologies were deposited on aluminum substrates through immersing the aluminum substrates perpendicularly into aqueous solution containing zinc nitrate hexahydrate and urea. Secondly, the films were then modified with fluoroalkylsilane (FAS: CH3(CF2)6(CH2)3Si(OCH3)3) molecules by immersing in absolute ethanol solution containing FAS. The morphologies, hydrophobicity, chemical compositions, and bonding states of the films were analyzed by scanning electron microscopy (SEM), water contact angle measurement (CA), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS), respectively. It was shown by surface morphological observation that HZC films displayed different microstructures such as microporous structure, rose petal-like structure, block-shaped structure, and pinecone-like structure by altering the deposition condition. A highest water contact angle of 156.2° was obtained after FAS modification. Moreover, the corrosion resistance of the superhydrophobic surface on aluminum substrate was investigated using electrochemical impedance spectroscopy (EIS) measurements. The EIS measurements’ results revealed that the superhydrophobic surface considerably improved the corrosion resistance of aluminum.

Long-Term Stable Metal Organic Framework (MOF) Based Mixed Matrix Membranes for Ultrafiltration

2020 ◽  
Author(s):  
Muayad Al-shaeli ◽  
Stefan J. D. Smith ◽  
Shanxue Jiang ◽  
Huanting Wang ◽  
Kaisong Zhang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Mixed Matrix Membranes ◽  
Recovery Ratio ◽  
Mixed Matrix ◽  
Water Contact ◽  
Membrane Performance ◽  
Metal Organic ◽  
Matrix Membranes

<p>In this study, novel <a>mixed matrix polyethersulfone (PES) membranes</a> were synthesized by using two different kinds of metal organic frameworks (MOFs), namely UiO-66 and UiO-66-NH<sub>2</sub>. The composite membranes were characterised by SEM, EDX, FTIR, PXRD, water contact angle, porosity, pore size, etc. Membrane performance was investigated by water permeation flux, flux recovery ratio, fouling resistance and anti-fouling performance. The stability test was also conducted for the prepared mixed matrix membranes. A higher reduction in the water contact angle was observed after adding both MOFs to the PES and sulfonated PES membranes compared to pristine PES membranes. An enhancement in membrane performance was observed by embedding the MOF into PES membrane matrix, which may be attributed to the super-hydrophilic porous structure of UiO-66-NH<sub>2</sub> nanoparticles and hydrophilic structure of UiO-66 nanoparticles that could accelerate the exchange rate between solvent and non-solvent during the phase inversion process. By adding the MOFs into PES matrix, the flux recovery ratio was increased greatly (more than 99% for most mixed matrix membranes). The mixed matrix membranes showed higher resistance to protein adsorption compared to pristine PES membranes. After immersing the membranes in water for 3 months, 6 months and 12 months, both MOFs were stable and retained their structure. This study indicates that UiO-66 and UiO-66-NH<sub>2</sub> are great candidates for designing long-term stable mixed matrix membranes with higher anti-fouling performance.</p>

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