• 한국세라믹학회지
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• 제27권5호
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• pp.638-644
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• 1990

The C3H8 gas sensitivities of SnO2, Pd-SnO2, Pt-SnO2 gas sensor are looked over with the impregnation method of PdCl2, H2PtCl6 solution on SnO2. The Cl- ion due to incomplete decomposition of PdCl2 at 80$0^{\circ}C$ for 30 min decrease the C3H8 gas sensitivity of SnO2, and the sensitivity is increased by the impreganation of H2PtCl6 solution on SnO2 because of its lower decomposition temperature compared with PdCl2. The C3H8 gas sensitivities of Pd-SnO2, Pt-SnO2 impregnated slightly after 1st sintering are larger than that of pure SnO2 sensor because very small amount of Cl- ion exist in sample due to smaller amount of impregnaiton.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2002년도 연료전지심포지움 2002논문집
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• pp.237-240
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• 2002

• Journal of the Korean Wood Science and Technology
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• 제23권4호
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• pp.1-9
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• 1995

This study was carried out to experiment the dimensional stabilization of woods of red pine (Pinus densiflora S. et Z.) and sugi(Cryptomeria japonica D. Don) by vacuum impregnation of polyehtylene glycols(PEG) with mo. wt. 200, 400, 600, 1000; polypropylene glycols (PPG) with mo. wt. 425,725 ; PEG-acryloylates, and PPG-acryloylates synthesized, and then by water soaking. The results obtained are as follows: 1. The density of sapwood and heartwood was different from each other in both species. 2. The PEG and PEG-macromers with lower molecular weight by impregnation has increased the density of wood specimens more higher, thereby caused their higher volume expansion, and those with higher molecular weight than 600 has tended to down their density increment. 3. Before and after water soaking, the density decrease of specimen impregnated was high in woods impregnated with simple PEG and PPG, while lower in specimens impregnated with PEG-macromers and PPG-macromers. 4. So PEG-macromer was expected to hold the original dimension of decayed wood for antiques, but it was necessary to develop another penetration method as well as aqueous solvent.

• 한국가구학회지
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• 제27권1호
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• pp.43-48
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• 2016

PEG (Polyethylene glycol) impregnation in wood reduces the occurrence of checking during kiln drying. The volumetric shrinkages of wood PEG impregnated by pressure (PEG-P) or soaking (PEG-S) methods, and oven-dried by vent (VD) or air-tight (AD) methods were measured and compared with the controls. The average oven-dry weight of PEG impregnated specimens was larger than that of the controls by 3.6 g, but was not influenced by the drying methods. The average of the total volumetric shrinkage of PEG-P-VD specimens was the least (2.3%), while that of CON-S-AD specimens was the largest (28.9%). Within a drying method the total volumetric shrinkage of the control was the largest followed by PEG-S and PEG-P specimens, which implied that residual PEG in wood restrained its shrinkage during drying.

• 한국화재소방학회논문지
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• 제26권4호
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• pp.18-23
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• 2012

이산화탄소 주조법에서 사용되고 있는 방법을 응용하여 목질내에 규산겔과 탄산소다, 이산화규소가 석출된 목재를 제조한 후 외부 복사열원(20, 25, 35 및 50 $kW/m^2$)에 따른 점화시간, 점화온도, 질량감소속도, 임계열유속을 측정하였다. 연구결과, 물유리와 이산화탄소를 이용한 가압함침 처리된 목재는 Pre-Flashover 단계에서의 복사열원(20 $kW/m^2$ 이하)에서 난연성능이 있음을 확인할 수 있었다. 향후 지속적인 연구를 통해 우수한 배합비율을 찾는다면 난연목재로서의 활용가능성이 있다고 판단된다.

• 한국구조물진단유지관리공학회 논문집
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• 제14권1호
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• pp.71-77
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• 2010

콘크리트 구조물은 여러 가지 열화현상으로 내구성 및 건전성이 크게 저하되므로, 열화현상을 억제하는 것이 중요하다. 본 연구에서는 콘크리트의 열화현상을 억제하여 성능을 개선 시킬 수 있는 경제적이고 효율적인 표면침투제의 사용방법을 도출하기 위하여 표면침투제의 종류, 농도, 함침시간을 달리한 시험체의 점도, 표면장력, 압축강도, 내약품성, 내흡수량 및 염소이온 침투저항성 시험결과를 고찰하였다. 그 결과, 콜로이달 실리카 용액 및 소듐 알루미나 실리케이트 용액의 적정 희석 농도와 함침시간은 각각 15%, 5분 및 17%, 10초로 나타났다.

• Advances in nano research
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• 제12권6호
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• pp.629-638
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• 2022

This work shows the impregnation of scents using a graphene sponge (GS). This was functionalized by the modified Hummers method, pursuing to add different functional groups. It is proposed to achieve the release and seek to control it through electrical potential applied to the graphene sponge with essential oils. The graphene sponge was functionalized and steeped with two kinds of oil. The electrochemical study demonstrates the variation in the electrochemical behaviour of the functionalized graphene sponge without and impregnated with oil. The release of the oil and its aromatic scents was carried out by applying an electrical potential of 30 V, with a release rate of 1.86 mg/min. The heating of the sample that causes the release of oil, associated with the electrical resistance of the system, reaches temperatures of about 150℃. The essential oils, graphene sponge, surfactant, graphene sponge with essential oils, graphene sponge recuperated after applying electric potential, graphene sponge recovered by temperature and dipropylene glycol (DPG) were characterized using Fourier transformed infrared spectroscopy (FTIR), digital microscopy, and x-ray photoelectron spectroscopy (XPS).

• 한국재료학회지
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• 제32권2호
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• pp.85-93
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• 2022

Porous mullite-corundum ceramics were prepared using organic foam impregnation method with alumina and silica as raw materials. The influence of alkaline treatment and surfactant modification on polyurethane foam were studied. Effects of sintering process and material composition on porous mullite-corundum ceramics were investigated. The results show that the hang-pulp quantity of polyurethane foam increases with alkaline treatment. After treatment with 3 wt% SDS solution, the hang-pulp quantity of polyurethane foam further improved. Open porosity of sample decreased with elevation of sintering temperature and holding time, and compressive strength of sample showed a trend opposite to the change of porosity. The open porosity of the sample was enhanced by the increase of m(Al₂O₃/SiO₂); the compressive strength decreased with increase of m(Al₂O₃/SiO₂). However, when m(Al₂O₃/SiO₂) was 2.5, the compressive strength of the sample reached 6.23 MPa, and the open porosity of the sample was 80.7 %.

• 한국재료학회지
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• 제22권8호
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• pp.421-425
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• 2012

Two types of Pt nanoparticle electrocatalysts were composited on Pt nanowires by a combination of an electrospinning method and an impregnation method with NaBH4 as a reducing agent. The structural properties and electrocatalytic activities for methanol electro-oxidation in direct methanol fuel cells were investigated by means of scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry. In particular, SEM, HRTEM, XRD, and XPS results indicate that the metallic Pt nanoparticles with polycrystalline property are uniformly decorated on the electro-spun Pt nanowires. In order to investigate the catalytic activity of the Pt nanoparticles decorated on the electro-spun Pt nanowires, two types of 20 wt% Pt nanoparticles and 40 wt% Pt nanoparticles decorated on the electro-spun Pt nanowires were fabricated. In addition, for comparison, single Pt nanowires were fabricated via an electrospinning method without an impregnation method. As a result, the cyclic voltammetry and chronoamperometry results demonstrate that the electrode containing 40 wt% Pt nanoparticles exhibits the best catalytic activity for methanol electro-oxidation and the highest electrochemical stability among the single Pt nanowires, the 20 wt% Pt nanoparticles decorated with Pt nanowires, and the 40 wt% Pt nanoparticles decorated with Pt nanowires studied for use in direct methanol fuel cells.

• Composites Research
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• 제31권6호
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• pp.317-322
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• 2018

다양한 산업군에서 복합재료를 적용한 제품개발을 진행하고 있는 상황이며, 재활용이 가능한 장점으로 인해 열가소성 복합재료에 대한 개발이 활발하다. 장섬유 강화 열가소성 플라스틱(Long fiber thermoplastic, LFT)의 형태도 있지만, 연속섬유를 이용한 열가소성 복합재료(Continuous fiber thermoplastic, CFT)에 대한 활용도 증가하고 있다. 본 연구에서는 CFT를 제작할 때 사용되는 강화섬유의 제직 패턴에 따른 영향으로 CFT의 인장, 굴곡, 충격 강도의 변화를 확인하고자 하였다. 복합재료의 물성이 강화섬유의 제직 패턴에 의해 달라지는 원인을 기계적인 물성으로도 평가하였고, CT 촬영기법을 이용하여 내부 기공발생과 섬유 제직패턴과의 상관관계를 분석하였다. CFT의 경우 열가소성 필름이 섬유 로빙 내로 함침되는 수준이 낮기 때문에, 공극의 발생률이 높은 문제가 있다. 섬유 로빙과 로빙사이의 계면이 $100{\mu}m$ 수준으로 조밀하게 형성될 수 있는 평직 섬유 패턴이 CFT의 성형성 및 기계적 물성을 안정화시키는 강화섬유의 조직임을 검증하였다.