• Carbon letters
• /
• 제2권2호
• /
• pp.105-108
• /
• 2001

In this work, the activated carbons (ACs) with high micropores were synthesized from the polystyrene (PS) with KOH as activating agent. And the influence of activation temperature on porosity of the ACs studied was investigated. The porous structures of ACs were characterized by nitrogen adsorption at 77K using BET and D-R equations, and MP and BJH methods. The weight loss behaviors of the samples impregnated with KOH were also monitored using thermogravimetric analyzer (TGA). As a result, it was found that the samples could be successfully converted into ACs with well-developed micropores. From the results of pore size analysis, it was confirmed that elevated activation temperature does lead to the formation and deepening of microstructures without significant change in mesostructures. A thermogravimetric study showed that KOH could suppress the thermal decomposition of the sample, resulting in the increase of carbon yields.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
• /
• pp.185-192
• /
• 2002

A laboratory scale thermogravimetric analyser was developed to investigate the combustion characteristics of selected solid fuel(wood) in the highly preheated air. The aims are to introduce in the means of experimental determination of the solid fuel particle characteristics through the combustion process in the environment of highly preheated air. A nearly single particle combustion condition was reproduced in a thermogravimetric analyser and regenerating combustor. For a fuel particle whose characteristic length was a few centimeter, the sub-processes of fuel drying, pyrolysis as well as the combustion of residual carbon were identified. Fluidized environment of carrier gas was selected as the major parameter which affect the combustion process.

• 공업화학
• /
• 제2권2호
• /
• pp.147-154
• /
• 1991

Poly acrylo-nitrile계(系) 섬유를 전구체로 하여 비등온과정(比等溫過程)에 의한 안정화(安定化) 및 탄화(炭化)를 승온속도(昇溫速度)를 달리한 TGA(thermogravimetric analysis)방법(方法)으로 연구하였다. 안정화과정(安定化過程)에서 cyclization과 탈수소(脫水素) 반응(反應)은 탄화과정중(炭化過程中) 세공발달(細孔發達)을 결정하는 주요한 요인(要因)이었으며, 세공(細孔) 및 탄화과정(炭化過程)의 $400^{\circ}C$ 이상에서 형성되기 시작하였다.

• 대한안전경영과학회지
• /
• 제10권4호
• /
• pp.111-120
• /
• 2008

The combustion reaction of polypropylene was investigated using a thermogravimetric technique under an air atmosphere condition at several heating rates from 10 to $50^{\circ}C/min$. To obtain information on the kinetic parameters, the dynamic thermogravimetric analysis curve and its derivative were analyzed by a variety of analytical methods such as Kissinger, Friedman, Freeman-Carroll, Chatterjee-Conrad, Ozawa and Coats-Redfern methods. The comparative works for the kinetic results obtained from various methods should be performed to determine the kinetic parameters, because there are tremendous differences in the calculated kinetic parameters depending upon the mathematical method taken in the analysis.

• 한국해양공학회지
• /
• 제15권2호
• /
• pp.130-134
• /
• 2001

Recently environmental pollution at sea becomes serious, so every governmental organization makes its effort to solve this problem. Combustible ocean wastes as of ropes, fishing nets, and tires are usually highly polymerized compound materials. The problem of ocean waste treatment can be solved by using the pyrolysis method. Pyrolysis characteristics of ocean waste was examined to get the basic data for the production system of fuel from the ocean waste. Thermogravimetric experiment showed that residual mass rate decreases as the velocity of temperature-rising becomes lower. The pyrolysis of waste rope and fishing net occurs at 300~450$^{\circ}C $ and the waste tire does at 350~450$^{\circ}C $. Pyrolysis time is estimated about 15 to 20 minutes in the temperature range when lively act of pyrolysis temperature reached.

• Bulletin of the Korean Chemical Society
• /
• 제34권1호
• /
• pp.149-153
• /
• 2013

The chemical functionalization of carboxylated multi-walled carbon nanotubes (MWCNT-COOH) by creatinine (MWCNT-Amide) and latter modification with 2-aminobenzophenone for producing 1-methyl-9-phenyl-1H-imidazo[4,5-b]quinolin-2-amine (MWCNT-quino) have been investigated. All products were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscope, elemental analysis, thermogravimetric analysis, derivative thermogravimetric and cellular investigations. The interesting point is that MWCNT-quino can be homogeneously dispersed in dimethylformamide and to some extent in ethyl alcohol without sonication. Also, MTT assay was used to examine the behavior of cell proliferation after 48 h of cell culture experiments. Cellular results showed high toxicity of MWCNT-quino on the cancer cells. These functionalizations have been chosen due to active sites of carbonyl and methylene groups in MWCNT-Amide and the creating quinoline derivative on the MWCNTs for future application.

• 대한화학회지
• /
• 제57권1호
• /
• pp.52-62
• /
• 2013

The interaction of titanium (IV), yttrium (III), zirconium (IV), palladium (II) and cerium (IV) with deprotonated enrofloxacin leads to the formation of the neutral or cationic mononuclear complexes. The isolated solid complexes have been characterized with physicochemical and spectroscopic techniques and thermogravimeteric analyses. The spectroscopic data indicate that the enrofloxacin ligand is on the deprotonated mode acting as bidentate ligand coordinated to the metal ions through the ketone oxygen and a carboxylato oxygen and the metal ions completed the coordination number with water molecules. The thermal decomposition mechanisms proposed for enrofloxacin and their metal complexes were discussed. The activation energies, $E^*$, enthalpies, ${\Delta}H^*$, entropies, ${\Delta}S^*$ and Gibbs free energies, ${\Delta}G^*$, of the thermal decomposition reactions have been derived from thermogravimetric (TG) and differential thermogravimetric (DTG) curves, using Coats-Redfern (CR) and Horowitz-Metzeger (HM) methods. The antimicrobial activity has been evaluated against six different microorganisms.

• 한국전기전자재료학회논문지
• /
• 제25권11호
• /
• pp.916-921
• /
• 2012

This research measured the dielectric properties of silicone rubber with various hardness in 100 Hz~3 MHz, $30{\sim}170^{\circ}C$ conditions. When the hardness increases from 65 degree to 75 degree, the dielectric loss increased within frequency range of 100 kHz~3 MHz and was a little change in dielectric loss within temperature range of $90^{\circ}C{\sim}170^{\circ}C$. Thermogravimetric Analysis (TGA) showed the weight change rate increased a little while heated until $800^{\circ}C$. Scanning Electron Microscope (SEM) measurement showed that Aluminium Trihydroxide($AlOH_3$) which acts as a reinforcement agent reduced the size of the particles as the hardness increased.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2011년도 제36회 춘계학술대회논문집
• /
• pp.296-297
• /
• 2011

본 연구에서는 PTFE 전기절연재의 수명예측을 위해 일련의 열중량 분석시험을 수행하였다. PTFE 시료는 온도상승률을 달리하며 상온에서 $700^{\circ}C$까지 온도를 가하였다. PTFE의 활성화에너지는 일정한 중량감소가 발생할 때의 로그 형태 온도상승률에 대한 변환온도 역수 선도에서 계산하였다. 또한 Toop에 의해 제안된 활성화 에너지와 추정 수명과의 관계식을 이용하면 주어진 운용온도 하에서의 PTFE 수명시간도 예측할 수 있다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2021년도 봄 학술논문 발표대회
• /
• pp.243-244
• /
• 2021

In this study, we develop diagnostic technology for damage depth of fire-damaged concrete and propose methods for damage caused by fire by drying damaged concrete after immersion. As a result of the test, the damaged depth was clearly found when evaluating the depth of impurities caused by fire in a drying method after water had permeated, and it could be verified using thermogravimetric analysis.