• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.395-404
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• 2019

In the case of fire, surface treatment agents used in external insulation finishing methods are substances that are vulnerable to fire due to thin finishes and the combustion of polymers. In this study, it was expected that the performance of surface preparation mortars could be improved by using expandable graphite with excellent thermal performance. Experimental results showed that the mechanical properties of surf ace preparation mortar were improved by using the fly ash and silica fume. Surface treatment materials using expanded graphite have a characteristic of expanding when a fire occurs. It has been shown that heat-swellable surface treatment materials can reduce the penetration of heat sources into the surface of synthetic insulation.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.221-222
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• 2013

다양한 첨가제가 들어가는 고분자 화합물(compound)의 제조에 있어 난연 발포 보조제인 팽창흑연(Expandable Graphite, EGP)은 흡유가가 낮기 때문에 비교적 많은 양을 첨가해도 혼합(Mixing)이 잘 되는 것으로 알려져 있다. 본 논문에서는 대표적인 인계 난연제 APP(Ammonium Polyphosphate)를 사용한 난연 EPDM(Ethylene Propylene Diene Monomer) 폼에 팽창흑연 첨가량을 증가시키면서 산소 지수와 발열량을 통해 난연 성능의 변화를 분석하였다. 산소지수는 ISO 4589-2 상온 산소지수 방법을, 발열량 평가는 ISO 5660-1 콘 칼로리미터를 활용하였다.

• 기계와재료
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• v.13 no.3 s.49
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• pp.139-145
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• 2001

• Composites Research
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• v.20 no.2
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• pp.10-16
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• 2007

The 2-step manufacturing method consisting of preforming and stamping processes was developed to manufacture composite bipolar plates for PEMFCS. The preform was composed of expanded graphite, graphite flake and phenol resin. Procuring conditions were optimized by checking the electrical conductivity, flexural strength and microstructure. Procuring temperature $(100^{\circ}C)$ slightly above the melting point of phenol powders $(90^{\circ}C)$ induced moderate curing, but also prevented excessive curing. Preforms utilizing the tangled structure of expanded graphite were easily fabricated at low pressure of 0.07-0.28MPa. The proper procuring time, 5min, was determined to fabricate the preform stably because insufficient and excessive procuring deteriorated the flexural strength of composite bipolar plates.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2001.05a
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• pp.157-160
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• 2001

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.32.1-32.1
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• 2009

본 연구에서는 산화 그라핀을 환원하여 얻은 그라핀 분말의 고온 XRD 패턴를 통해 그라핀의 열팽창계수를 정량하였다. 산화 그라핀은 Hummer method에 의해 제조되었다. 또한 그라핀은 산화그라핀을 1273K에서 열처리하여 얻어졌다. 1273K에서 그라핀의 열팽창계수($32.9{\pm}1.0$ X 10-6 K-1)는 원료인 흑연(30.3 X 10-6 K-1) 보다 8.6% 더 크게 나타내는것을 알 수 있었다. 그라핀은 화학적 처리에 의한 급격한 면간 팽창과 열처리에 의한 aggregation에 의해 심하게 굴곡지고 적층된 morphology를나타냈다. 이는 박리효과에 의한 것으로 XRD 패턴을 통해그라핀의 층수가 흑연보다 훨씬 적은 것을 알 수 있었다. 이에 따라 면간 규칙적인 배열을 보이는 흑연과는 달리 그라핀은 흑연구조에서 흔히 보이는 disorder 구조인turbostratic 적층 구조를 나타나고 면간인터렉션이 약화되어 열팽창계수가 크게 나타난다고 생각된다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.11a
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• pp.181-186
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• 1999

화학 축열 시스템의 성능을 모사하고 이를 해석하여 시스템 성능을 최적화하기 위해서는, 반응층의 열 및 물질 전달 특성을 정확히 아는 것이 중요하다. 본 연구에서는 $Na_2$S-$H_2O$ 반응계를 사용한 화학 열펌프에 대한 연구로, $Na_2$S-팽창흑연 복합체의 열전도도와 기체 투과도를 측정하였고, 소형 시스템을 제작하여 그 성능을 평가하였다. 열전도도는 전이 일차원 열류기법을 사용하여 측정하였고, 기체 투과도는 Darcy's law를 이용하여 측정하였다. 반응층의 열전도도와 기체 투과도는 팽창흑연 지지체의 겉보기 밀도와 반응염의 함량에 따라 각각 6~48W/mㆍK, 1.1$\times$$10^{-13}$~1.0$\times$$10^{-11}$m$^2$의 범위에 있었다. 또한 소형 시스템을 구성하여 445W/kgㆍ$Na_2$S의 냉방 출력을 얻을 수 있었다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.105-106
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• 2022

Now, the world is increasingly anxious about fine dust due to abnormal temperatures caused by global warming and increased yellow dust caused by desertification, and the World Health Organization (WHO) pointed out that more than 99% of the world's population is exposed to fine dust. In this situation, the reduction rate of fine dust and carbon dioxide of the matrix was tested by using expanded graphite, an eco-friendly and porous material, to improve air quality. As a result of the test, since expanded graphite is a material that expands between layers compared to conventional graphite, the reduction rate of fine dust and carbon dioxide decreases as the replacement rate of expanded graphite increases.

• Journal of Korea Foundry Society
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• v.42 no.5
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• pp.307-313
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• 2022

• Journal of Korean Society of Water and Wastewater
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• v.26 no.2
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• pp.275-283
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• 2012

MCM-41(Mobil's Composition of Matter-41) and expanded graphite(EG) were investigated as potential adsorbents for heavy metal ions including Pb(II), Cu(II) and Ni(II) in various aqueous chemistries. MCM-41 showed shorter equilibrium times and higher adsorption capacities for all three heavy metal ions compared to expanded graphite. The adsorption of three heavy metal ions was significantly affected by the solution pH due to the competition with $H_{3}O^{+}$ at lower pH and precipitation at neutral or higher pH. Adsorptions of heavy metal ions onto MCM-41 and expanded graphite were successfully described with the pseudo-second-order model. During the competitive adsorption of three heavy metal ions, the selectivity of Pb(II) was highest and almost same selectivity was observed with Cu(II) and Ni(II) when MCM-41 was used as an adsorbent, while the expanded graphite exhibited the highest selectivity to Pb(II), followed by Ni(II) and Cu(II).