• 제목/요약/키워드: superhydrophobicity

검색결과 65건 처리시간 0.043초

Improvement of Superhydrophobicity of Multi-Walled Carbon Nanotubes Produced by Fluorination

  • Meng, Long-Yue;Park, Soo-Jin
    • Carbon letters
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    • 제13권3호
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    • pp.178-181
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    • 2012
  • In this work, we synthesized superhydrophobic coatings by chemical surface functionalization of multi-walled carbon nanotubes (MWCNTs). This was accomplished through the radical polymerization of 3-(trimethoxysilyl) propyl methacrylate modified MWCNTs and fluoro acrylate/methyl methacrylate. The chemical compositions and microstructures of the prepared MWCNT surface were investigated using X-ray photoelectron spectroscopy, Fourier transform infrared spectrometry, and scanning electron microscopy, respectively. The wettability of the MWCNTs surface was determined through contact angle assessments in different liquids. The resulting surface exhibited a water contact angle of $157.7^{\circ}$, which is clear evidence of its superhydrophobicity. The 3D MWCNT networks and the low surface energy of the -C-C- and -C-F- groups play important roles in creating the superhydrophobic surface of the MWCNTs.

플라즈마 처리에 의한 PMMA, PET, ABS의 초발수 효과 (Plasma treatment on PMMA, PET & ABS for Superhydrophobicity)

  • 최경린;노정현;이준희;김완두;임현의
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1582-1584
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    • 2008
  • This paper reports a simple fabrication method for creating the superhydrophobic polymer surface using a plasma etching. Generally, it is necessary for the superhydrophobic surfaces to have a rough structure on surface with the composition of the low surface energy. In this study, Poly(methyl methacrylate) (PMMA), poly(ethylene terephthalate) (PET), acrylonitrile butadiene styrene (ABS) with superhydrophobic surface were fabricated using $O_2$ plasma etching and vapor deposition with the fluoroalkylsilane self-assembled monolayers. The plasma treated polymer surfaces are covered with the nano-pillar shaped structures after treatment for $1{\sim}2min$. And these samples with FOTS SAMs coating are showed the superhydrophobicity having the water contact angle of around $150^{\circ}$ and sometimes around $180^{\circ}$ depending on the treatment time. Furthermore the nanostructured polymer is transparent for the visible light.

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나노마이크로 구조의 자기세정 기능성 코팅막의 제조 (Preparation of Self-Cleaning Coating Films with Nano- and Microstructure)

  • 정아롱;김준수;윤존도
    • 한국재료학회지
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    • 제22권8호
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    • pp.416-420
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    • 2012
  • Recently nanoscience and nanotechnology have been studied intensively, and many plants, insects, and animals in nature have been found to have nanostructures in their bodies. Among them, lotus leaves have a unique nanostructure and microstructure in combination and show superhydrophobicity and a self-cleaning function to wipe and clean impurities on their surfaces. Coating films with combined nanostructures and microstructures resembling those of lotus leaves may also have superhydrophobicity and self-cleaning functions; as a result, they could be used in various applications, such as in outfits, tents, building walls, or exterior surfaces of transportation vehicles like cars, ships, or airplanes. In this study, coating films were prepared by dip coating method using polypropylene polymers dissolved in a mixture of solvent, xylene and non-solvent, methylethylketon, and ethanol. Additionally, attempts were made to prepare nanostructures on top of microstructures by coating with the same coating solution with an addition of carbon nanotubes, or by applying a carbon nanotube over-coat on polymer coating films. Coating films prepared without carbon nanotubes were found to have superhydrophobicity, with a water contact angle of $152^{\circ}$ and sliding angle less than $2^{\circ}$. Coating films prepared with carbon nanotubes were also found to have a similar degree of superhydrophobicity, with a water contact angle of 150 degrees and a sliding angle of 3 degrees.

나노입자 마스크를 이용하여 제작한 초소수성 마이크로-나노 혼성구조 (Fabrication of Superhydrophobic Micro-Nano Hybrid Structures by Reactive Ion Etching with Au Nanoparticle Masks)

  • 이초연;윤석본;장건익;윤완수
    • 한국진공학회지
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    • 제19권4호
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    • pp.300-306
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    • 2010
  • 소수성 고분자를 사용하여 제작한 마이크로구조에 금 나노입자를 마스크로 이용하는 반응성이온식각(RIE: Reactive Ion Etching)을 적용하여 초소수성을 갖는 마이크로-나노 혼성구조를 제작하였다. 소수성 고분자로는 PFPE (perfluoropolyether bisurethane methacrylate)를 사용하였으며 마이크로 단일구조는 PDMS (polydimethylsiloxane) 몰드를 사용하는 스탬핑 방식으로 제작하였다. 다양한 형태로 제작한 PFPE 마이크로 단일구조와 마이크로-나노 혼성구조의 표면 접촉각을 측정하여 표면 미세구조에 따른 소수성의 변화를 관찰하였다. 마이크로 단일구조의 경우 접촉각은 안정적인 값을 보이지 못하였으나 단일 구조에 나노입자를 사용한 식각을 적용해 나노구조가 형성됨에 따라 $150^{\circ}$ 이상의 접촉각을 갖는 초소수성 표면이 매우 높은 재현성으로 용이하게 형성되었다.

Underwater Stability of Surface Chemistry Modified Superhydrophobic WOx Nanowire Arrays

  • Lee, Junghan;Yong, Kijung
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.357.1-357.1
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    • 2014
  • Superhydrophobic WOx nanowire (NW) arrays were fabricated using a thermal evaporation and surface chemistry modification methods by self-assembled monolayer (SAM). As-prepared non-wetting WOx NWs surface shows water contact angle of $163.2^{\circ}$ and has reliable stability in underwater conditions. Hence the superhydrophobic WOx NWs surface exhibits silvery surface by total reflection of water layer and air interlayer. The stability analysus of underwater superhydrophobicity of WOx NWs arrays was conducted by changing hydrostatic pressure and surface energy of WOx NWs arrays. The stability of superhydrophobicity in underwater conditions decreased exponentially as hydrostatic pressure applied to the substrates increased3. In addition, as surface energy decreased, the underwater stability of superhydrophobic surface increased sharply. Specifically, sueprhydrophobic stability increased exponentially as surface energy of WOx NWs arrays was decreased. Based on these results, the models for explaining tendencies of superhydrophobic stability underwater resulting from hydrostatic pressure and surface energy were designed. The combination of fugacity and Laplace pressure explained this exponential decay of stability according to hydrostatic pressure and surface energy. This study on fabrication and modeling of underwater stability of superhydrophobic W18O49 NW arrays will help in designing highly stable superhydrophobic surfaces and broadening fields of superhydrophobic applications even submerged underwater.

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광촉매와 초발수 처리를 이용한 셀프클리닝 섬유의 제조 및 평가 (Preparation and Evaluation of Self-cleaning Fabrics using Photocatalyst and Superhydrophobic Finishing)

  • 정의경;우희주;조승빈;배진석
    • 한국염색가공학회지
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    • 제30권4호
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    • pp.288-293
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    • 2018
  • This study reported the dual functional self-cleaning PET fabrics prepared from $TiO_2$ and hexadecyltrimethoxysilane treatment, which have photodegradation and superhydrophobicity on the fabric surface. Phodegradation and superhydrophobicity of the resulting fabric were compared with $TiO_2$ or silane treated fabrics. The dual functional self-cleaning PET fabric showed less photodegradation than the $TiO_2$ treated fabric. However, the dual functional self-cleaning fabrics showed superior superhydrophobicity to silane treated fabric with increased water contact angle and significantly decreased roll-off angle. This suggested that the dual functional PET fabric has a great potential to be the commercialized self-cleaning fabric because it is repellent to soil or dust and even if soil or dust is adsorbed on the fabric surface, it can be removed by water rolling off on the surface or photodegradation by the photocatalyst.

Fabrication of a Superhydrophobic Surface with Adjustable Hydrophobicity and Adhesivity Based on a Silica Nanotube Array

  • Yu, Jae-Eun;Son, Sang-Jun
    • Bulletin of the Korean Chemical Society
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    • 제33권10호
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    • pp.3378-3382
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    • 2012
  • A superhydrophobic surface with a water contact angle > $150^{\circ}$ has attracted great interest from both fundamental and practical aspects. In this study, we demonstrated that hydrophobicity of a silica nanotube (SNT) array can be easily controlled by the SNT aspect ratio. In addition, the adhesive and anti-adhesive properties were controlled without modifying the hydrophobic surface. Various silica structures on a polydimethylsiloxane substrate were prepared using the desired alumina template. Bundle-arrayed and bowl-arrayed silica surfaces exhibited extraordinary superhydrophobicity due to the large frontal surface area and hierarchical micro/nanostructure. As the strategy used in this study is biocompatible and a wide range of hydrophobicities are capable of being controlled by the SNT aspect ratio, a hydrophobic surface composed of an SNT array could be an attractive candidate for bioapplications, such as cell and protein chips.

Bioinspired Nanoengineering of Multifunctional Superhydrophobic Surfaces

  • Choi, Chang-Hwan
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2015년도 추계학술대회 논문집
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    • pp.102-133
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    • 2015
  • Nature, such as plants, insects, and marine animals, uses micro/nano-textured surfaces in their components (e.g., leaves, wings, eyes, legs, and skins) for multiple purposes, such as water-repellency, anti-adhesiveness, and self-cleanness. Such multifunctional surface properties are attributed to three-dimensional surface structures with modulated surface wettability. Especially, hydrophobic surface structures create a composite interface with liquid by retaining air between the structures, minimizing the contact area with liquid. Such non-wetting surface property, so-called superhydrophobicity, can offer numerous application potentials, such as hydrodynamic drag reduction, anti-biofouling, anti-corrosion, anti-fogging, anti-frosting, and anti-icing. Over the last couple of decades, we have witnessed a significant advancement in the understanding of surface superhydrophobicity as well as the design, fabrication, and applications of superhydrophobic coatings/surfaces/materials. In this talk, the designs, fabrications, and applications of superhydrophobic surfaces for multifunctionalities will be presented, including hydrodynamic friction reduction, anti-biofouling, anti-corrosion, and anti-icing.

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양극산화 모드 전환을 통한 기능성 알루미늄 표면 연구 (Fabrication of functional aluminum surface through anodization mode transition)

  • Park, Youngju;Jeong, Chanyoung
    • 한국표면공학회지
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    • 제55권6호
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    • pp.417-424
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    • 2022
  • This research develops an easy-to-use, environmentally friendly method for fabricating functional 1050 aluminum alloy surfaces with excellent corrosion resistance. Functional aluminum surfaces with various nanostructures are fabricated by controlling the experimental conditions of anodizing process. The experiment used a multi-step anodizing process that alternates between two different anodizing modes, mild anodizing (MA) and hard anodizing (HA), together with a pore-widening (PW) process. Among them, the nanostructured surface with a small solid fraction shows superhydrophobicity with a contact angle of more than 170° after water-repellent coating. In addition, the surface with superhydrophobicity is difficult for corrosive substances to penetrate, so the corrosion resistance is greatly improved.