• 한국전기전자재료학회논문지
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• 제21권5호
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• pp.402-410
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• 2008

Single-walled carbon nanotubes (SWCNTs) were currently produced together with some contaminants such as a metallic catalyst, amorphous carbon, and graphitic nanoparticles, which should be sometimes purified for their applications. This study aimed to develop efficient, scalable purification processes but less harmful to SWCNTs. We designed three-step purification processes: acidic treatment, surface functionalization and soxhlet extraction, and heat treatment. During the soxhlet extraction using tetrahydrofuran, specifically, carbon impurities could be easily expelled through a glass thimble filter without any significant loss of CNTs. Finally, SWCNTs were left as a bulky paper on the filter through membrane filtration. Vertically aligned SWCNTs on one side of bulky paper were well developed in a speparation from the filter paper, which were formed by being sucked through the filter pores during the pressurized filtration. The bucky paper showed a very high peak current density of field emission up to $200\;mA/cm^2$ and uniform field emission images on phosphor, which seems very promising to be applied to vacuum microelectronics such as microwave power amplifiers and x-ray sources.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.196-197
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• 2006

Among various polymerization methods to graft polymers on the surface of CNTs, Atom Transfer Radical Polymerization (ATRP) has several advantages, such as a wide range of polymerizable monomers and superb control in molecular structure and weights. Several research groups including us have showed that ATRP is an efficient and versatile method to modify the surface of CNTs. Here, two independent approaches for the covalent attachment of polymers based on ATRP graft-from and graft-onto methods will be discussed.

• Bulletin of the Korean Chemical Society
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• 제24권2호
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• pp.161-162
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• 2003

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.413-413
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• 2014

In this paper, we present a fabrication method of functionalized gold nanostructures on flexible substrate that can be implemented for plasmonic sensing application. For biomolecular sensing, many researchers exploit unconventional lithography method like nanoimprint lithography (NIP), contact transfer lithography, soft lithography, colloidal transfer printing due to its usability and easy to functionalization. In particular, nanoimprint and contact transfer lithography need to have anti-adhesion layer for distinctive metallic properties on the flexible substrates. However, when metallic thin film was deposited on the anti-adhesion layer coated substrates, we discover much aggravation of the mold by repetitive use. Thus it would be impossible to get a high quality of metal nanostructure on the transferred substrate for developing flexible electronics based transfer printing. Here we demonstrate a method for nano-pillar mold and transfer the controllable nanoparticle array on the flexible substrates without an anti-adhesion layer. Also functionalization of gold was investigated by the different length of thiol applied for effectively localized surface plasmonic resonance sensing. First, a focused ion beam (FIB) and ICP-RIE are used to fabricate the nanoscale pillar array. Then gold metal layer is deposited onto the patterned nanostructure. The metallic 130 nm and 250 nm nanodisk pattern are transferred onto flexible polymer substrate by bi-layer functionalized contact imprinting which can be tunable surface energy interfaces. Different thiol reagents such as Thioglycolic acid (98%), 3-Mercaptopropionic acid (99%), 11-Mercaptoundecanoic acid (95%) and 16-Mercaptohexadecanoic acid (90%) are used. Overcoming the repeatedly usage of the anti-adhesion layer mold which has less uniformity and not washable interface, contact printing method using bi-layer gold array are not only expedient access to fabrication but also have distinctive properties including anti-adhesion layer free, functionalized bottom of the gold nano disk, repeatedly replicate the pattern on the flexible substrate. As a result we demonstrate the feasibility of flexible plasmonic sensing interface and anticipate that the method can be extended to variable application including the portable bio sensor via mass production of stable nanostructure array and other nanophotonic application.

• 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.

• 세라미스트
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• 제23권2호
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• pp.166-177
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• 2020

The wettability is one of the most fundamental properties of a material surface. Especially, graphene, two-dimensional (2D) surface material in which all the carbon atoms are exposed to the environment, is the best choice of template to study about the surface wettability. However, most studies have focused on the mechanical and electrical properties of graphene, not the surface wettability. This review article covers the wettability of graphene and provides recent research regarding the engineering of the surface wettability. This paper would be helpful for researchers working in this field and provides perspective for future carbon-liquid interacting applications.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2005년도 추계학술발표대회 논문집
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• pp.75-78
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• 2005

Using a low-energy Ar+ ion-beam with and without reactive gases, polymers such as chemically stable poly(ether ether ketone) (PTFE) and poly(ether ether ketone) (PEEK) films were modified to have special surface features. The adhesion strength between the polymers and the copper was significantly improved because of both changes in the surface topography and chemical interactions due to polymer surface functionalization (oxidation and amination). The surface modification altered the failure mode from adhesive failure for the unmodified polymer/Cu interface to cohesive failure for the surface-modified polymer/Cu layer interface..

• 폴리머
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• 제35권6호
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• pp.548-552
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• 2011

본 연구에서는 기능화된 다중벽탄소나노튜브를 준비하기 위해서 두 가지 기능화 방법인 산처리와 화학적 아미드화 방법이 수행되었다. 그리고 에폭시/기능화된 다중벽탄소나노튜브 복합재료의 특성이 연구되고 비교되었다. 기능화 방법에 따른 다중벽탄소나노튜브의 표면 관능기를 확인하기 위해 푸리에 변환 적외선 분광기(FTIR)를 사용하였다. 계면 및 열전도도에 미치는 다중벽탄소나노튜브 기능화의 효과는 제타전위차 분석기, 전자주사현미경 그리고 열전도도 분석기에 의해서 연구되었다. 이러한 결과들로 에폭시/기능화된 다중벽탄소나노튜브 복합재료의 열전도도는 dodecylamine과의 그래프팅을 통해 증가될 수 있다는 것을 알 수 있었다. 이것은 DGEBF 에폭시 수지 내에서 dodecylamine과 그래프팅한 다중벽탄소나노튜브의 상대적으로 강한 분산력에 의한 것으로 설명될 수 있었다. 이러한 결과들은 그래프팅한 다중벽탄소나노튜브의 제타전위차 값이 산처리한 다중벽탄소나노튜브의 값보다 더 높은 음의 값을 가지는 결과와 일치하였다.

• 폴리머
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• 제36권1호
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• pp.111-116
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• 2012

메조포러스 물질의 표면을 post-synthesis grafting method를 통해 표면을 기능화시킨 후 $(n-BuCp)_2ZrCl_2$/methylaluminoxane(MAO)를 담지하여 에틸렌 중합을 실시하였다. 아민기와 시안기를 가지는 유기실란 $N$-[(3-trimethoxysilyl)propyl]ethylenediamine(2NS), 4-(triethoxysilyl)butyronitrile(1NCy), 1-(3-triethoxysilylpropyl)-2-imidazoline(2NIm)는 메조포러스 물질의 표면 기능화에 사용되었다. SBA-15/2NS/$(n-BuCp)_2ZrCl_2$촉매 담지시 MAO의 양이 증가할수록 Zr 함량은 감소하였고 Al 함량은 증가하였다. 에틸렌 중합 활성은 MAO의 양이 증가할수록 급격히 증가함을 볼 수 있었다. 담지시간이 6시간일 때 가장 높은 활성을 보였다. 유기실란의 종류에 따른 활성 차이는 SBA-15/2NS/$(n-BuCp)_2ZrCl_2$ > SBA-15/2NIm/$(n-BuCp)_2ZrCl_2$ > SBA-15/1NCy/$(n-BuCp)_2ZrCl_2$ 순으로 감소하였다. 아민기를 두 개 갖는 2NS와 2NIm은 아민기를 하나 갖는 1NCy보다 $(n-BuCp)_2ZrCl_2$와 더 강하게 상호작용을 한다. 따라서 촉매 내 질소와 Zr함량이 증가할수록 활성은 증가하였다.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1596-1600
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• 2010

Surface functionalization of multi-walled carbon nanotubes (MWNTs) was carried out by means of acid treatment. The presence of oxygen functional groups on the surface of acid-treated MWNTs was confirmed with the aid of Fourier transform infrared spectroscopy and X-ray spectroscopy. In addition, carboxylic groups generally formed on the surface of acid-treated MWNTs, and the dispersion was increased by the duration of the acid treatment. The zeta-potential indicated the surface charge transfer and the dispersion of MWMTs. Morphological characteristics of acid-treated MWNTs were also observed using a transmission electron microscopy, X-ray diffraction, and Raman analysis, which was revealed the significantly unchanged morphologies of MWNTs by acid treatment. The hydrogen adsorption capacity of the MWNTs was evaluated by means of adsorption isotherms at 77 K/1 atm. The hydrogen storage capacity was dependent upon the acid treatment conditions and the formation of oxygen functional groups on the MWNT surfaces. The latter have an important effect on the hydrogen storage capacity.