• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.8-8
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• 2011

During the last half decade, chemically modified graphene (CMG) has been studied in the wide range of applications, such as polymer composites, energy-related materials, sensors, 'paper'-like materials, field-effect transistors (FET), inks, actuators, and biomedical applications due to its excellent electrical, mechanical, and thermal properties. Chemical modification of graphene oxide, which is generated from graphite oxide, which is produced by simple oxidation of graphite, has been a promising route to achieve mass production of CMG platelets via their colloidal suspensions. Graphene oxide contains a range of reactive oxygen functional groups, which renders it a good candidate for use in the aforementioned applications (among others) through chemical functionalizations. In this presentation, I will discuss my recent research activities on the fundamental chemistry of graphite oxide, as well as novel applications based on CMGs. Topics will include the chemical structure of CMGs and colloidal suspensions of CMG platelets, as well as a wide variety of applications.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.192-192
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• 2012

The next generation electronics need to not only be smaller but also be more flexible. To meet such demands, electronic devices using two dimensional (2D) atomic crystals like graphene, hexagonal boron nitride (h-BN), molybdenum disulfate ($MoS_2$) and organic thin film have been studied intensely. In this talk, I will demonstrate the $MoS_2$ field effect transistor (FET) toward performance enhancement by insulating h-BN substrate.

• 반도체디스플레이기술학회지
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• 제16권1호
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• pp.102-105
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• 2017

Currently, the size of the electronic device is in the nano area. In order to control the movements of these nanoscale devices, one should be able to understand the physical phenomena in the nano area. Recently, due to carbon nanotubes and mechanical outstanding electrical conductivity and mechanical characteristics of the carbon nanotubes and Graphene behaves to apply. Efforts have been active. There are various tubes with a radius of a in a compact mass in the form of a Multi walled carbon nanotubes in different between the radius. Van der Waals force can move smoothly without friction with each other by the nanoscale motor turning, using the properties, making. This is the lightest solids per unit area on the thickness is electrical atomic layer one of the substance and the electrical conductivity, the best material and mechanical characteristics are very much. Many studies because great is the ideal nanoelectromechanical device of material is being considered. In this study, electrical resonator for a new structure proposed and the nature and methodology would like to come up.

• 대한방사성의약품학회지
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• 제4권2호
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• pp.115-120
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• 2018

In recent years, many researchers have attempted to make use of 2D nanoparticles as molecular imaging probes since extensive investigations proved that 2D nanoparticles in the body tends to accumulate certain lesions by enhanced permeability and retention (EPR) effect. For example, graphene and carbon nitride which have high surface area and modifiable properties showed good biocompatibility and targetability when it used as imaging probes. However, poor dispersibility in physiological mediums and its uncontrolled size limited its usage in bio-application. Therefore, oxidation process and mechanical exfoliation have been developed for overcoming these problems. In this paper, we highlight the several major methods to synthesize biocompatible 2D nanomaterials like graphene and carbon nitride especially for molecular imaging study including positron emission tomography (PET).

• Advances in nano research
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• 제16권5호
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• pp.435-444
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• 2024

Microscopic defects within the microstructure of hardened cement paste are the main source of weakness in concrete. As a solution, nano-graphene oxide (GO) can be employed to improve the cement paste microstructure. However, there is a number of disadvantages, e.g., fluidity reduction and non-uniform dispersion. The present study sought to modify GO by fabricating a copolymer (PSGO) in a novel process to exploit the advantages of nano-GO while minimizing its disadvantages. Using 0.03wt% copolymerled to 38.8% higher tensile strength, 29.3% higher compressive strength and 25% higher workability. The SEM images revealed that GO and modified GO enhanced concrete by secondary hydration and bonding with C-S-H, creating a firm, integrated, and foil-like structure, and reducing the crack size and depth.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.201.2-201.2
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• 2015

현대 디지털 사회에서 고효율 에너지와 파워소스에 관한 요구가 커짐에 따라 차세대 에너지 저장 소자에 대한 연구가 계속되고 있다. 그 중 리튬이온 배터리, 슈퍼커패시터, 그리고 연료 전지들이 우리의 일상생활에서 점점 더 중요하게 자리잡아가고 있는데 이런 다양한 에너지 저장소자 중 슈퍼커패시터가 많은 관심을 받고 있다. 이는 긴 수명, 빠른 충-방전 속도, 높은 에너지 밀도, 그리고 안전함 때문이다. 슈퍼커패시터는 에너지 저장 메커니즘에 따라 두 가지로 분류될 수 있는데 전기이중층 커패시터(EDLC)와 슈도커패시터(pseudocapacitor)로 나누어질 수 있다. 슈도커패시터는 active 물질과 전해질 이온 간의 전기화학적 반응으로 인해 EDLC보다 더 많은 에너지를 저장할 수 있다. 그러므로 지금까지 새로운 형태의 슈도용량성 물질을 만들기 위한 노력이 집중되고 있다. 본 연구에서는 전기화학적증착 방법을 통해 graphene-like ${\beta}$-nickel hydroxide (${\beta}-Ni(OH)_2$) 나노판 구조를 전도성 직물에 합성하였다. ${\beta}-Ni(OH)_2$ 슈도커패시터의 유연하고 효율적인 비용의 전극으로서 높은 비정전용량, 우수한 전기화학 가역성, 그리고 뛰어난 사이클 안정성을 보였다. 이런 쉬운 방법으로 유연한 전도성 직물에 합성된 metal hydroxide/oxide 나노구조는 웨어러블 에너지 저장소자와 변환소자 분야에 사용될 것으로 기대된다.

• 한국기계기술학회지
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• 제20권6호
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• pp.858-864
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• 2018

Graphene oxide (GO) laminate is a new promising material for water purification system, which has extraordinary permeability only for water molecule. It consists of numerous nano-channels, in which water molecules could be nano-confined, resulting in slip of the molecules for very fast transportation speed. In this study, water penetration rate via different thickness of GO membrane according to driven pressures are measured experimentally, so that speed of water molecules and permeability are evaluated. Generally, water penetration rate via a membrane with macroscopic-sized channel increases linearly with pressure difference between up and bottom side of the membrane, but that via GO membrane approaches asymptotic value (i.e. saturation) as like a log function. Moreover, the permeability of GO membrane was observed in inverse proportion to its thickness. Based on the experimental observations, a correlation for volume flux via GO membrane was suggested with respect to its thickness and external pressure difference.

• 멤브레인
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• 제32권1호
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• pp.1-12
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• 2022

그래핀옥사이드는 우수한 물리적 특성 및 가공성으로 멤브레인 소재로 각광받고 있다. 특히, 이론적 예측과 실험적인 접근을 통해 그래핀옥사이드의 원자 수준의 얇은 두께, 뛰어난 기계적 강도, 높은 수준의 내화학성, 기공 생성이 가능한 2차원 구조 또는 기체 확산 유로 생성이 가능한 적층구조 등 멤브레인 소재로서 매우 유리한 특성들을 보유하고 있음이 밝혀졌다. 또한 그래핀옥사이드에서의 분자 투과 거동은 적층된 그래핀옥사이드 사이의 채널 크기에 따라 영향을 받는다는 것이 발견되었다. 그 후, 이러한 특성을 응용하여 그래핀옥사이드를 멤브레인 소재로 활용하기 위해 많은 연구가 집중적으로 진행되고 있다. 본 총설에서는 그래핀옥사이드의 고유 특성을 기반으로 멤브레인 분야로의 응용 가능성에 대하여 논하고자 한다.

• 한국전기전자재료학회논문지
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• 제27권7호
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• pp.417-427
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• 2014

Renewable energy sources such as solar, wind and hydro provides utilizing renewable power and reduce the using fossil fuels. On the other hand, it is too critical to apply power system due to the intermittent nature of renewable energy sources, the continuous fluctuations of the power load, and the storage with high energy density. Energy storage system, including pumped-hydroelectric energy storage, compressed-air energy storage, superconducting magnetic energy storage, and electrochemical devices like batteries, supercapacitors and others have shown that solve some of the challenges. In this paper, we review the current state of applications of energy storage systems, and atomic layer deposition technology, graphene materials on the energy storage systems and processes.

• 한국정밀공학회지
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• 제28권11호
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• pp.1251-1258
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• 2011

With the help of nanoscale materials like carbon nanotube (CNT), there is the potential to develop new actuators that will provide higher work per cycle than previous actuator technologies, and generate much higher mechanical strength. In this study, the electrochemical actuation characteristics of nano carbon materials were experimentally studied to develop electrochemical actuators. The electrochemical actuators were composed of aqueous NaCl electrolyte and their actuating electrodes were made of multi-walled carbon nanotube (MWCNT)/polystyrene composite and graphene respectably. Actuation is proportional to charging transfer rate, and the electrolysis with an AC voltage input has very complex characteristics. To quantify the actuation property, the strain responses and output model were studied based on electrochemical effects between the nano carbon films and the electrolyte.