Pore size effect on the formation of polymer nanotubular structures within nanoporous templates

Cho, Y.,Lee, C.,Hong, J. Elsevier 2014 Colloids and surfaces. A, Physicochemical and engi Vol.443 No.-

Nanotubular structures have recently received much attention due to their potential applications in biosensors, drug delivery systems, electronic devices, and many others. The layer-by-layer (LbL) deposition technique on 3-dimensional templates has been one of the most popular methods for the formation of nanotubular structures. Any size, shape, and composition template can be utilized and the desired amount of various materials can be readily incorporated within the thin film geometry with nanoscale control. Therefore, the morphological features of those materials can easily be tuned by varying the structural properties of templates. However, LbL deposition within a confined geometry actually shows somewhat different results due to the geometrical restriction, which is still not fully understood so far. In the present study, in order to investigate such a template effect on the LbL process, we utilized a cylindrical nanoporous anodic aluminum oxide (AAO) structure as a template for the LbL process, yielding polymer nanotube structures. By varying the pore size of the porous templates, we determined the LbL process within porous structures was strongly governed by the geometrical characteristics of the utilized templates.

Beneficial effect of steam on synthesis of hierarchically porous zeolite-templated carbons

Han Jinju,Kim Kyoungsoo 대한화학회 2022 Bulletin of the Korean Chemical Society Vol.43 No.7

Hierarchically meso-/microporous carbons were synthesized using nanocrystalline beta zeolite as a sacrificial template. The zeolite template possessed intercrystalline mesopores in addition to ordered micropores of the nanocrystals. Various amounts of steam were used with a carbon source, such as ethylene, propylene or acetonitrile, to generate a carbon structure inside the template. The synthesis results showed that adding a suitable amount of steam gave rise to faithful replication of the ordered microporous structure, while the intercrystalline mesopores were retained. That is, the carbon structure was formed selectively inside nanocrystalline zeolites rather than at the exterior by the steam addition. Microscopic observation and thermogravimetric analysis revealed that steam oxidized the carbon species deposited at the external surface of zeolite nanocrystals, and hence inhibited the undesirable carbon deposition. Furthermore, such a beneficial effect of steam could be applied for the carbon synthesis using other type zeolite templates.

Synthesis of Nanoporous Carbon as a Gas Adsorbent by Reverse Replication Process of Silica Template

Cho, Churl-Hee,Kim, Joon-Soo,Kim, Hong-Soo,Ahn, Young-Soo,Han, Moon-Hee,Yoo, Jong-Sung The Korean Ceramic Society 2003 한국세라믹학회지 Vol.40 No.6

Porous carbon with high surface area and pore volume was prepared by a reverse replication process and its toluene equilibrium adsorption behavior was investigated. The preparation process of the porous carbon was composed of fellowing sub-processes in series: synthesis and template preparation of silica gel, impregnation and polymerization of DVB monomer in silica template, carbonization of DVB polymer in a silica-polymer composite, and HF-assisted selective etching of silica in carbon-silica composite. The prepared porous carbon was nano porous and had ultrahigh specific surface area (2007 ㎡/g) and large pore volume (3.07 ㎤/g). The nanoporous carbon showed rapid toluene adsorption rate and good toluene adsorption capacity, compared with a commercial Y-type zeolite. In the present study, a reverse replication process to prepare nanoporous carbons will be introduced and its application potential as a gas adsorbent will be discussed.

CdTe/GaAs Nanodot Arrays and Carbon Nanotubes Prepared Utilizing Nanoporous Alumina Templates

Sun-il Mho,WENSUN,정미,In-Hyeong Yeo 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.5

Nanoporous alumina templates were prepared by anodizing grain-free aluminum at constant voltage. The self-assembled hexagonally close-packed alumina cell result in ordered cylindrical nanohole arrays with interpore spacings ranging from 50 to 150 nm and pore sizes from 25 to 120 nm. Long-range-ordered CdTe nanodot arrays with controlled size and density were grown on GaAs substrates by using molecular-beam epitaxy with ultrathin nanoporous alumina masks; uniform dot sizes in the ranges of 35 nm (with a density of 2.5 10¹0 cm-²) and 80 nm (with a density of ~8.1 x 10 9 cm-²) were prepared as replicas of the alumina masks. The specic capacitances of the carbon nanotube (CNT) electrodes for electrochemical double-layer capacitors were significantly enhanced, a maximum value of 175 F g-¹, by using the nanoporous alumina/aluminum templates with high pore density and uniform pore diameter.

Highly Ordered Nanoporous Template from Triblock Copolymer

Lee, Dong Hyun,Park, Soojin,Gu, Weiyin,Russell, Thomas P. American Chemical Society 2011 ACS NANO Vol.5 No.2

<P>Silica nanoporous templates from poly(1,4-isoprene)-<I>block</I>-polystyrene-<I>block</I>-poly(2-vinyl pyridine) (IS2VP) were prepared. The films of IS2VP spin-coated from toluene showed a dimple-type structure with short-range lateral order. When the films were exposed to a mixed solvent vapor of toluene/hexane, a highly ordered and oriented core−shell structure, consisting of an outer shell of PI, a middle shell of PS, and a core of P2VP, was obtained. The PI was degraded by UV-ozone treatment and removed. A film of polydimethylsiloxane (PDMS) was spin coated onto the remaining film with dimple-type structures and, upon heating, was drawn into the interstitial regions by capillary action. Exposure to oxygen plasma converted the PDMS into silica and degraded all other remaining polymers. This led to highly ordered and oriented nanoporous silica that could be used as an etching mask for transfer of the pattern or templates for metal loading.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2011/ancac3.2011.5.issue-2/nn102832c/production/images/medium/nn-2010-02832c_0009.gif'></P>

A nanoporous substrate-based low temperature solid oxide fuel cell using a thin film Ni anode

Lee, Sanghoon,Cho, Gu Young,Park, Taehyun,Lee, Yoon Ho,Yu, Wonjong,Lee, Yeageun,Chang, Ikwhang,Cha, Suk Won Elsevier 2018 THIN SOLID FILMS - Vol.666 No.-

<P><B>Abstract</B></P> <P>A thin film solid oxide fuel cell (TF-SOFC) with a Ni anode on a nanoporous anodic aluminum oxide substrate was demonstrated. In our experiments, Ni was used as an anode material, while a very small amount of Pt was used as a cathode material, which reduced the thickness of the thin film cathode to 65 nm. In addition, a plasma-enhanced atomic layer deposition method was used to prepare a yttria-stabilized zirconia electrolyte. The open circuit voltage and the peak power density of the as-fabricated fuel cells, both of which were measured at 500 °C, were 1.04 V and 150 mW/cm<SUP>2</SUP>, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Thin film solid oxide fuel cell(TF-SOFC) with Ni/YSZ/Pt was demonstrated. </LI> <LI> The peak power density of 150 mW/cm<SUP>2</SUP> was measured at 500 °C. </LI> <LI> Ni is significantly comparable to Pt for hydrogen oxidation reaction. </LI> </UL> </P>

SELF-ASSEMBLY OF THREE-DIMENSIONAL NANOPOROUS CONTAINERS

JAIHAI WANG,MIRA PATEL,DAVID H. GRACIAS 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2009 NANO Vol.4 No.1

We describe a strategy to construct three-dimensional (3D) containers with nanoporous walls by the self-assembly of lithographically patterned two-dimensional cruciforms with solderhinges. The first step involves fabricating two-dimensional (2D) cruciforms composed of six unlinked patterns: each pattern has an open window. The second step entails photolithographic patterning of solder hinges that connect the cruciform. The third step involves the deposition of polystyrene particles within the windows and the subsequent electrodeposition of metal in the voids between the polystyrene particles. Following the dissolution of the particles, the cruciforms are released from the substrate and heated above the melting point of the solder causing the cruciforms to spontaneously fold up into 3D cubic containers with nanoporous walls. We believe these 3D containers with nanoporous side walls are promising for molecular separations and cell-based therapies.

Application of Nano-porous Templates with High Aspect Ratio using Block Copolymer Thin Films

이정인,유재웅,김진곤 한국고분자학회 2004 한국고분자학회 학술대회 연구논문 초록집 Vol.29 No.2

센서 응용을 위한 다공성 골드의 제조

김휘로(Hero Kim),김영훈(Younghun Kim),고재욱(Jae Wook Ko) 한국가스학회 2008 한국가스학회지 Vol.12 No.2

U-safety system 구축을 위한 휴대 및 설치가 편리한 액상/기상 센서가 요구되고 있다. 나노다공성 알루미나를 구조유도체로 사용한 다공성 골드(Au)를 제조하여 센서의 전극 및 센서기질로 사용하였다. 제조한 다공성 골드는 평균 200~300 nm의 윈도우 기공을 갖고, 4.8 m<SUP>2</SUP>/g의 비표면적을 갖는 100% 순수한 골드로 구성되어 있다. 다공성 골드는 우수한 전기전도성, 불순물의 탈·부착에 따른 저항 변화 측정의 간편성, 좋은 재현성을 가져 액상/기상 센서의 기질로 사용하기에 적합하다. 본 연구에서는 검증실험으로 실시간 수은 검출실험을 실시하여, 센서로서의 활용 가능성을 확인하였다. For a development of U-safety system, liquid/gas-sensors that are easy to carry and install in any place are needed. Therefore, in this work, we prepared porous gold using a templating method with nanoporous alumina, and it was used as sensing materials and electrode. The resulting materials showed high purity macroporous structure with 200~300 nm of window-pore and 4.8 m<SUP>2</SUP>/g of surface area. Because porous gold had good electric conductivity, convenience to measure the change of electric resistivity and good reproducibility, it could be used as potential sensing materials. As a proof-of-concept test, the detection test for mercury ion was carried out.

다른 형태의 폴리머 나노구조체의 합성: 나노구조체 와 속이 빈 캡슐형

유종성 Elsevier 2006 CURRENT APPLIED PHYSICS Vol.6 No.-