• Proceedings of the Materials Research Society of Korea Conference
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• 2011.10a
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• pp.30.2-30.2
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• 2011

나노 채널 구조는 반응 물질의 빠른 확산 경로를 제공하고, 넓은 반응 활성화 면적을 가지므로, 센서, 촉매, 전지 등의 다양한 기능성 전기 화학 소자용 고효율 전극 구조로서 관심을 받고 있다. 최근 양극 산화법을 이용하여, 자가 배열된 나노 채널 구조의 주석 산화물을 형성시키는 연구가 진행되고 있다. 그러나, 기재위에 도금된 주석 박막이 양극 산화에 의해 산화물로 변화하는 과정에서 내부 균열 및 표면 기공의 막힘 현상이 관찰되고, 기재 위 주석의 산화가 완료되는 시점에서는 기재의 산화 및 산소 발생에 의한 기계적 충격 등으로 인해 산화물이 기재로부터 탈리되는 문제가 발생하여, 그 응용 연구가 크게 제한되어 있는 실정이다. 본 연구에서는 다공성 주석 산화물 합성 시의 구조적 결함이 나타나는 이유에 대해 체계적으로 분석하고, 이를 바탕으로 결함이 없는 나노 채널 주석 산화물을 제조하는 방법을 제시하였다. 또한, 주석 산화물 박막을 기능성 전기화학 소자용 전극 활물질, 특히 리튬 전지용 음극재료로 사용하기 위한 효과적인 전극 제조 방법에 대해 논의하고, 그에 따라 제조된 전극의 충방전 용량, 사이클링 안정성 등을 제시하였다.

• Transactions of the KSME C: Technology and Education
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• v.3 no.4
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• pp.249-255
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• 2015

Functional nanochannels were fabricated in order to control selective ion transportation with high permeability and low energy consumption. In this research, nanochannel platform fabrication process and surface functionalization process were developed. In addition, selective ion transportation and concentration measurement system was also set-up. By using fabricated multilayer metal membrane with electrical bias, 95% of ion ($Cl^-$) was blocked. This developed process is new-conceptional membrane fabrication technology and is expected to be applied to next-generation water purification/desalination, portable artifical kidney, and artificial sense organ.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.173-174
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• 2007

• Membrane Journal
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• v.26 no.6
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• pp.421-431
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• 2016

Novel membrane technologies that harness ordered nanostructures have recently received much attention because they allow for high permeability due to their reduced flow resistance while also maintaining high selectivity due to their isoporous characteristics. In particular, the opaline structure (made from the self-assembly of colloidal particles) and its inverted form (inverse-opal) have shown strong potential for membrane applications on account of several advantages in processing and the resulting membrane properties. These include controllability over the pore size and surface functional moieties, which enable a wide range of applications ranging from size-exclusive separation to catalytically-reactive membranes. Furthermore, when combined with multiscale architecturing strategies, inverse-opal-structured membranes can be designed to have specific pores or channel structures. These materials are anticipated to be utilized for next-generation, high-performance, and high-value-added functional membranes. In this review article, various types of inverse-opal-structured membranes are reviewed and their functionalization through hierarchical structuring will be comprehensively investigated and discussed.

• Membrane Journal
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• v.28 no.6
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• pp.388-394
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• 2018

Carbon nanotube (CNT) based membranes are promising candidates for separation membranes by showing high water transport rate and ion rejection rate according to their radii. The ion selectivity is an important factor to discover the full potential of CNT membranes, and it is affected by the functionalization of CNTs. With multivalent/size ion mixtures, the ion selectivity is affected by not only ion-functional groups interaction but also ion-ion interactions and ion size exclusion in a complex manner. In this study, molecular dynamics simulations are performed to study the ion selectivity of functionalized carbon nanotubes when multivalent/size ions are contained. The permeation energy barriers are calculated by plotting potential of mean force profiles, and various factors, such as CNT size and partial charges, affecting ion selectivity are investigated. The results presented here will be useful for designing CNT membranes for ion separation, biomimetic ion channels, etc.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.12
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• pp.1144-1149
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• 2007

Experimental studies on the fabrication of sub-30 nm nanofibers using weakly two-photon induced photopolymerized region have been carried out. For the generation of nanofibers inside or outside microstructures, an over-polymerizing method involving a long exposure technique (LET) was proposed. Such nanofibers can find meaningful applications as bio-filters, mixers, and many other uses in diverse research field. A multitude of nanofibers with a notably high resolution (about 22 nm) in two-photon polymerization was achieved using the LET. Furthermore, it was demonstrated that the LET can be employed for the direct fabrication of various embossing patterns by controlling the exposure duration and the interval between yokels. Thin interconnecting networks are formed regularly in the boundary of the over-polymerized region, which allows for the creation of various pattern shapes. Overall of this work, some patterns including nanofibers are fabricated by the LET.