• Journal of Electrochemical Science and Technology
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• 제3권3호
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• pp.143-148
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• 2012

The unique effects of highly conductive conducting polymer/SWNT (single walled carbon nanotube) composite nanoparticles in electric double layer capacitors are studied for the enhancement of the adhesive properties, specific capacitance and power characteristics of the electrode. Because the conducting polymer/SWNT composite material, which is believed to act as a polymer binder, an active material for charge storage and a conducting agent, is well distributed on the activated carbon, greatly enhanced adhesion properties, cell capacitance and power characteristics were obtained.

• Carbon letters
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• 제12권2호
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• pp.90-94
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• 2011

We present the effect of a coupling agent on the optoelectrical properties of few-walled carbon nanotube (FWCNT)/epoxy resin hybrid films fabricated on glass substrates. The FWCNT/epoxy resin mixture solution was successfully prepared by the direct mixing of a $HNO_3$-treated FWCNT solution and epoxy resin. FWCNT/binder hybrid films containing different amounts of the coupling agent were then fabricated on UV-ozone-treated glass substrates. To determine the critical binder content ($X_c$), the effects of varying the binder content in the FWCNT/silane hybrid films on their optoelectrical properties were investigated. In this system, the $X_c$ value was approximately 75 wt%. It was found that above $X_c$, the coupling agent effectively decreased the sheet resistance of the films. From microscopy images, it was observed that by adding the coupling agent, more uniform FWCNT/binder films were formed.

• 공업화학
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• 제9권7호
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• pp.979-984
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• 1998

Nylon6,6를 matrix로 사용하여 전도성 고분자인 polyaniline(PANI)과의 전도성 복합체를 블렌딩 방법에 의하여 제조하였다. 블렌딩은 m-cresol를 용매로 사용하였으며 PANI는 camphorsulfonic acid(CSA) 혹은 dodecylbenzenesulfonic acid (DBSA)와 같은 알킬 벤젠 술폰산으로 양성화시켰다. 또한, 비상용성인 두 고분자간의 혼화성을 개선시키기 위하여 가소제를 첨가하여 상분리를 최대한 억제시켰다. 제조된 전도성 복합체에 대하여 양성화제의 유무에 따라 또는 PANI의 함량에 따라 전기전도도 및 몰포로지 등을 측정 분석하였다. PANI 착체의 함량이 증가할수록 전기전도도는 증가하였고, 알킬 사슬의 길이가 긴 DBSA로 양성화된 PANI(25wt%)과 가소화된 nylon6,6의 전도성 복합체의 전기전도도는 1.02 S/cm까지 향상되었다.

• 공업화학
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• 제10권2호
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• pp.287-292
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• 1999

Polycarbonate (PC)를 matrix로 사용하여 전도성 고분자인 polyaniline (PANI)과의 복합체를 블렌딩 방법에 의하여 제조하였다. 용매로는 chloroform을 사용하였으며 PANI는 전하수송을 가능하게 하고 유기용매에 잘 용해될 수 있도록 camphorsulfonic acid (CSA) 혹은 dodecylbenzenesulfonic acid (DBSA)와 같은 알킬 벤젠 술폰산으로 양성화시켰다. 또한, 전도성 복합체의 전기전도성은 압축성형이 아닌 solution casting법에 의하여 향상시켰다. 아울러 양성화제 유무, PANI의 함량 또는 온도에 따라 전기전도도, 몰포로지 및 인장강도 등을 측정 분석하였다. PANI 착체의 함량이 많을수록 전기전도도는 증가하였으며 알킬사슬이 긴 DBSA로 양성화된 25 wt % PANI 착체의 전도성 복합체의 전기전도도는 3.18 S/cm까지 향상되었다.

• 공업화학
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• 제10권2호
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• pp.281-286
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• 1999

Nylon6,6를 matrix로 사용하여 전도성 고분자인 polypyrrole (PPy)과의 전도성 복합체를 블렌딩 방법에 의하여 제조하였다. PPy를 화학적으로 중합시키는데 있어서 $FeCl_3$를 산화제로 사용하였으며, dopant로서 camphorsulfonic acid (CSA)와 dodecylbenzenesulfonic acid (DBSA)와 같은 알킬 벤젠 술폰산을 사용하였다. 제조된 전도성 복합체에 대하여 dopant의 종류에 따라 또는 PPy의 함량에 따라 전기전도도 및 몰포로지 그리고 기계적 물성 등을 측정 분석하였다. PPy 착체의 함량이 증가할수록 전기전도도는 증가하였으며, 알킬사슬의 길이가 긴 DBSA로 도핑된 25 wt % PPy 착체와 nylon6,6 복합체의 전기전도도는 0.64 S/cm까지 향상되었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.143-146
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• 2007

Birnessite-type manganese dioxide($MnO_2$) was coated uniformly onto carbon nanotubes (CNTs) through a spontaneous direct redox reaction between CNTs and permanganate ions($MnO_4\;^-$). The initial specific capacitance of the $MnO_2/CNT$ nanocomposite in an organic electrolyte at a large current density of 1 A/g was 250 F/g, which is equivalent to 139 mAh/g based on the total weight of the electrode material including the electroactive material, conducting agent and binder. The specific capacitance of the $MnO_2$ in the $MnO_2/CNT$ nanocomposite was as high as 580 F/g (320 mAh/g), indicating excellent electrochemical utilization of the $MnO_2$. The addition of CNTs as a conducting agent can improve the high rate capability of $MnO_2/CNT$ nanocomposite considerably. An analysis of the in-situ X-ray absorption near-edge structure (XANES) showed an improvement in the structural and electrochemical reversibility of the $MnO_2/CNT$ nanocomposite by heat-treatment.

• 한국군사과학기술학회지
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• 제27권4호
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• pp.528-534
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• 2024

In continuous research of detecting highly toxic chemical warfare agents to ensure preparedness for the future battlefield, flexible and wearable sensor platforms with high sensitivity are still demanding. Herein we demonstrate a facile fabrication of polypyrrole-based chemiresistors on cellulose paper for the detection of nerve gas simulants. In order to optimize electrical properties of sensor platform, conducting polymer made of polypyrrole were first synthesized on flexible cellulose paper and interdigitated electrodes were formed thereon. Following confirmation of polypyrrole and/or oxime moiety through FT-IR analyses, electrical characteristics were measured in the various ratio of monomers between simple pyrrole and oxime-modified one. Typically for the optimized chemiresistor(2:8 molar ratio of simple pyrrole and oxime-modified one), eleven species of chemical warfare agents were examined and enhanced conductivity(10⁴~10⁵ order) was observed for three simulants(diethyl cyanophosphonate, diisopropyl fluorophosphonate and diethyl chlorophosphonate), which was mainly attributed to intermolecular hydrogen bonding, while no significant responses was recorded against sixteen common volatile organic chemicals.

• 소성∙가공
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• 제18권3호
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• pp.256-261
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• 2009

Polyurethane has been one of the most important materials for automobile elastic parts such as bumper, head rest, instrument panel and so on since it covers very wide range of mechanical characteristics with low production costs. The processing variables such as formulation of ingredients and mold temperature, mixing speed, etc. can affect the quality of produced polyurethane foams so that process conditions should be determined appropriately. In this study, foaming behaviors of semi-rigid polyurethane were investigated by conducting cup foam tests with two major processing variables such as environmental temperature and blowing agent content. In addition, it was verified that processing conditions of real practice can be determined effectively by considering foaming characteristics obtained by the cup foam tests.

• Korean Journal of Radiology
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• 제25권3호
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• pp.257-266
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• 2024

Objective: To investigate molecular and functional consequences of additional exposures to iodine- or gadolinium-based contrast agents within 24 hours from the initial intravenous administration of iodine-based contrast agents through an animal study. Materials and Methods: Fifty-six Sprague-Dawley male rats were equally divided into eight groups: negative control, positive control (PC) with single-dose administration of CT contrast agent, and additional administration of either CT or MR contrast agents 2, 4, or 24 hours from initial CT contrast agent injection. A 12 µL/g of iodinated contrast agent or a 0.47 µL/g of gadolinium-based contrast agent were injected into the tail vein. Serum levels of blood urea nitrogen, creatinine, cystatin C (Cys C), and malondialdehyde (MDA) were measured. mRNA and protein levels of kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) were evaluated. Results: Levels of serum creatinine (SCr) were significantly higher in repeated CT contrast agent injection groups than in PC (0.21 ± 0.02 mg/dL for PC; 0.40 ± 0.02, 0.34 ± 0.03, and 0.41 ± 0.10 mg/dL for 2-, 4-, and 24-hour interval groups, respectively; P < 0.001). There was no significant difference in the average Cys C and MDA levels between PC and repeated CT contrast agent injection groups (Cys C, P = 0.256-0.362; MDA, P > 0.99). Additional doses of MR contrast agent did not make significant changes compared to PC in SCr (P > 0.99), Cys C (P = 0.262), and MDA (P = 0.139-0.771) levels. mRNA and protein levels of KIM-1 and NGAL were not significantly different among additional CT or MR contrast agent groups (P > 0.05). Conclusion: A sufficient time interval, probably more than 24 hours, between repeated contrast-enhanced CT examinations may be necessary to avoid deterioration in renal function. However, conducting contrast-enhanced MRI on the same day as contrast-enhanced CT may not induce clinically significant kidney injury.

• 로봇학회논문지
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• 제19권3호
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• pp.293-310
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• 2024

In this paper, we propose an agent model for Language-Driven Zero-Shot Object Navigation (L-ZSON) tasks, which takes in a freeform language description of an unseen target object and navigates to find out the target object in an inexperienced environment. In general, an L-ZSON agent should able to visually ground the target object by understanding the freeform language description of it and recognizing the corresponding visual object in camera images. Moreover, the L-ZSON agent should be also able to build a rich spatial context map over the unknown environment and decide efficient exploration actions based on the map until the target object is present in the field of view. To address these challenging issues, we proposes AML (Agent Model for L-ZSON), a novel L-ZSON agent model to make effective use of AI foundation models such as Large Language Model (LLM) and Vision-Language model (VLM). In order to tackle the visual grounding issue of the target object description, our agent model employs GLEE, a VLM pretrained for locating and identifying arbitrary objects in images and videos in the open world scenario. To meet the exploration policy issue, the proposed agent model leverages the commonsense knowledge of LLM to make sequential navigational decisions. By conducting various quantitative and qualitative experiments with RoboTHOR, the 3D simulation platform and PASTURE, the L-ZSON benchmark dataset, we show the superior performance of the proposed agent model.