• Title/Summary/Keyword: phase change materials

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Shape-Stabilized Phase Change Materials : Frozen Gels From Polypropylene and n-Paraffin for Latent Heat Storage

  • Kim, Jong-Hwan;Ko, Jae-Wang;Son, Tae-Won
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2009.03a
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    • pp.120-121
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    • 2009
  • We prepared polymer-PCM gels such as prepared frozen gel from polypropylene and n-Paraffin for thermal storage and release materials, their basic properties and possible applications especially in latent heat storage. The preparation methods are used to melting method and absorption method respectively. The composition and properties of prepared frozen gels from polypropylene and n-Paraffin were observed by DSC, FT-IR spectra, ARES and Elemental analysis. We can prepare frozen gels in different temperature for latent heat storage materials as controlling composition of phase change material as well as using different incorporating phase change materials. These frozen gels can be used to latent heat storage materials for several applications.

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The study of phase-change according to temperature and voltage in chalcogenide thin film (칼코게나이드 박막의 온도, 전압에 따른 상변화에 관한 연구)

  • Yang, Sung-Jun;Shin, Kyung;Park, Jung-Il;Nam, Lee-Ki;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.416-419
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    • 2003
  • There is a growing need for a nonvolatile memory technology with faster speed than existing nonvolatile memories. We studied of phase-change according to temperature and voltage in chalcogenide thin film base on $Ge_2Sb_2Te_5$. Searching for Tg(Glass transition temperature) temperature controlled on hotplate with RT quenching. We measure I-V characteristic through out bottom electrode(ITO) and top electrode(Al) between $Ge_2Sb_2Te_5$. And compared with I-V characteristics after impress the variable stress.

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Shape-Stabilized Phase Change Materials : Frozen Gels From Polypropylene and n-Paraffin for Latent Heat Storage

  • Ko, Jae-Wang;Son, Tae-Won
    • Proceedings of the Korean Society of Dyers and Finishers Conference
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    • 2010.03a
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    • pp.80-81
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    • 2010
  • We prepared polymer-PCM gels such as prepared frozen gel from polypropylene and n-Paraffin for thermal storage and release materials, their basic properties and possible applications especially in latent heat storage. The preparation methods are used to melting method and absorption method respectively. The composition and properties of prepared frozen gels from polypropylene and n-Paraffin were observed by DSC, FT-IR spectra, ARES and Elemental analysis. We can prepare frozen gels in different temperature for latent heat storage materials as controlling composition of phase change material as well as using different incorporating phase change materials. These frozen gels can be used to latent heat storage materials for several applications.

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Analysis of Monoclinic Phase Change and Microstructure According to High-temperature Heat Treatment of Oxide-doped YSZ (산화물이 Doping된 YSZ의 고온 열처리에 따른 Monoclinic 상변화 및 미세구조 분석)

  • Gye-Won, Lee;Yong-Seok, Choi;Chang-Woo, Jeon;In-Hwan, Lee;Yoon-Suk, Oh
    • Journal of Powder Materials
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    • v.29 no.6
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    • pp.468-476
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    • 2022
  • Yttria-stabilized zirconia (YSZ) has a low thermal conductivity, high thermal expansion coefficient, and excellent mechanical properties; thus, it is used as a thermal barrier coating material for gas turbines. However, during long-time exposure of YSZ to temperatures of 1200℃ or higher, a phase transformation accompanied by a volume change occurs, causing the YSZ coating layer to peel off. To solve this problem, YSZ has been doped with trivalent and tetravalent oxides to obtain coating materials with low thermal conductivity and suppressed phase transformation of zirconia. In this study, YSZ is doped with trivalent oxides, Nd2O3, Yb2O3, Al2O3, and tetravalent oxide, TiO2, and the thermal conductivity of the obtained materials is analyzed according to the composition; furthermore, the relative density change, microstructure change, and m-phase formation behavior are analyzed during long-time heat treatment at high temperatures.

The Phase-change Memory Characteristics of Ge1Se1Te2 Thin Films for Sb Photo Doping (Sb 광도핑에 의한 Ge1Se1Te2 박막의 상변화 메모리 특성)

  • Nam, Ki-Hyun;Kim, Jang-Han;Chung, Hong-Bay
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.5
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    • pp.329-333
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    • 2012
  • For phase transition method, good record sensitivity, low heat radiation, fast crystallization and hi-resolution are essential. Also, a retention time is very important part for phase-transition. In our past papers, we chose composition of $Ge_1Se_1Te_2$ material to use a Se factor which has good optical sensitivity than conventional Sb. Sb/Ge-Se-Te thin films are fabricated and irradiated with UV light source to investigate a reversible phase change by Sb-doped condition. Because of Sb atoms, the Sb inserted sample showed better performance than conventional one. We should note that this novel one showed another possibility for phase-change random access memory.

Optical properties of Ag/$Ge_1Se_1Te_2$ material with secondary Ag layer adoption (두 번째 Ag 층을 적용한 Ag/$Ge_1Se_1Te_2$ 물질의 광학적 특성 연구)

  • Kim, Hyun-Koo;Han, Song-Lee;Kim, Jae-Hoon;Koo, Sang-Mo;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.191-192
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    • 2008
  • For phase transition method, good record sensitivity, low heat radiation, fast crystallization and hi-resolution are essential. Also, a retention time is very important part for phase-transition. In our past papers, we chose composition of $Ge_1Se_1Te_2$ material to use a Se factor which has good optical sensitivity than conventional Sb. Ge-Se-Te and Ag/$Ge_1Se_1Te_2$ samples are fabricated and irradiated with He-Ne laser and DPSS laser to investigate a reversible phase change by light. Because of Ag ions, the Ag layer inserted sample showed better performance than conventional one. We should note that this novel one showed another possibility for phase-change random access memory.

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The Analysis of the Energy Saving Performances of Building Materials using Phase Change Materials (상변화물질을 적용한 건축자재의 에너지절약 가능성 분석)

  • An, Sang-Min;Hwang, Suck-Ho;Kim, Tae-Yeon;Leigh, Seung-Bok
    • 한국태양에너지학회:학술대회논문집
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    • 2011.04a
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    • pp.162-167
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    • 2011
  • Thermal storage plays an important role in building energy saving, which is greatly assisted by the incorporation of latent heat storage in building materials. A phase change material is a substance with a high heat of fusion which, melting and solidifying at a certain temperature, can be storing and releasing large amount of energy. Heat is stored or released when the material changes from solid to liquid. Integration of building materials incorporating PCMs into the building envelope can result in increased efficiency of the built environment. The aim of this research is to identify thermal performance of PCMs impregnated building materials which is applied to interior of building such as gypsum and red clay. In order to analyze thermal performance of phase change materials, test-cell experiments and simulation analysis were carried out. The results show that micro-encapsulated PCM has an effect to maintain a constant indoor temperature using latent heat through the test-cell experiments. PCM wallboard makes it possible to reduce the fluctuation of room temperature and heating and cooling load by using EnergyPlus simulation program. Phase change material can store solar energy directly in buildings. Increasing the heat capacity of a building is capable of improving human comfort by decreasing the frequency of indoor air temperature swings so that the interior air temperature is closer to the desired temperature for a long period of time.

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Overview of the Current Status of Technical Development for a Highly Scalable, High-Speed, Non-Volatile Phase-Change Memory

  • Lee, Su-Youn;Jeong, Jeung-Hyun;Cheong, Byung-Ki
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.8 no.1
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    • pp.1-10
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    • 2008
  • The present status of technical development of a highly scalable, high-speed non-volatile PCM is overviewed. Major technical challenges are described along with solutions that are being pursued in terms of innovative device structures and fabrication technologies, new phase change materials, and new memory schemes.

Phase change on reflection considered of the polarization in white-light interferometer (백색광 주사 간섭계에서 편광을 고려한 반사시 위상 변화)

  • 김영식;김승우
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.276-279
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    • 2003
  • The phase change upon reflection from target surfaces in white-light interferometer induces measurement errors when target surfaces are composed of dissimilar materials. We prove that this phase change on reflection considered of the polarization of the white-light causes the shift of both envelope peak position and fringe peak position of several tens of nanometer. In addition, we propose a new equation of white-light interference fringe pertinent to the polarization of source.

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Preparation of Polyurea Microcapsules Containing Phase Change Material and their Application on Fiber Composites (상전이물질을 함유한 폴리우레아 마이크로캡슐의 제조와 섬유복합소재에의 적용)

  • Kim, Hea-In;Jin, Xuan-Zhen;Choi, Hae-Wook;Park, Soo-Min
    • Textile Coloration and Finishing
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    • v.19 no.1 s.92
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    • pp.37-44
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    • 2007
  • In this study, for textile use, the octadecane of phase change materials(PCM) was encapsulated in several micro-diameter shell which prevents leakage of the material during its liquid phase. Microencapsulated PCM(PM) was prepared with the different weight ratio of core material to wall material and by interfacial polymerization methods using polyurea as shell material. Phase stability for O/W emulsion of PCM and PVA aq. (PE) was evaluated by Turbiscan Lab. The capsule formation win identified using FT-IR. Physical properties of microcapsules including diameter, particle distribution, morphology were investigated. Thermal transport properties of suede treated with PM(SPM) were determined by KES-F7 system.