• Title, Summary, Keyword: encapsulation

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A Case Study of Paraffin Double-walled Microencapsulation Preparation Using Acrylic Polymer and Melamine Polymer for Thermal Energy Storage

  • Nguyen, Hang Vo-Minh;Kim, Chae-Hyun;Kim, Jong-Kuk
    • Journal of the Korean Solar Energy Society
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    • v.39 no.5
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    • pp.65-78
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    • 2019
  • In this study, we investigated the paraffin encapsulation using double-walled encapsulation technique. The first encapsulation used methyl methacrylic acid as the main component in acrylic polymer and the second encapsulation used melamine polymer. Particles size and distribution of the capsules were analyzed using scanning electron microscopy. In the first encapsulation, the stable capsules were obtained at 67% of phase change material ratio to methyl methacrylic acid monomer and the size of the capsule was from 0.2 to $0.3{\mu}m$. In the second encapsulation, the size of the capsules was almost the same with those capsules prepared in the first encapsulation. The particle size of single wall and double wall was about $0.3{\mu}m$. As a result of the encapsulation of paraffin using double-walled encapsulation technique, it was confirmed that the particle size was determined in the process of encapsulating using the acrylic polymer at the first wall material, and the physical and thermal stability of the capsules were imparted using melamine at the secondary wall material.

A Study on Optimal Process Conditions for Chip Encapsulation (반도체 칩 캡슐화 공정의 최적조건에 관한 연구)

  • 허용정
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.477-480
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    • 1995
  • Dccisions of optimal filling conditions for the chip encapsulation have been done primarily by an ad hoc use of expertise accumulated over the years because the chip encapsulation process is quite complicated. The current CAE systems do not provide mold designers with necessary knowledge of the chip encapsulation for the successful design of optimal filling except flow simulation capability. There have been no attempts to solve the optimal filling problem in the process of the chip encapsulation. In this paper, we have constructed an design system for optimal filling to avoid short shot in the chip encapsulation process which combines an optimization methodology with CAE software.

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Encapsulation of Bacillus polyfermenticus SCD with Alginate-Methylcellulose and Evaluation of Survival in Artificial Conditions of Large Intestine

  • Kim Cheon-Jei;Jun Song-Ae;Lee Na-Kyoung;Kim Kee-Tae;Lee Si-Kyung;Kim Chang-Han;Paik Hyun-Dong
    • Journal of Microbiology and Biotechnology
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    • v.16 no.3
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    • pp.443-449
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    • 2006
  • Bacillus polyfermenticus SCD was studied for its increasing stability by encapsulation, using 2, 3, and 4% sodium alginate. In these cases, 3% alginate resulted in the maximum survival of B. polyfermenticus SCD in artificial gastric juice for 3 h. Effects of several biopolymers on the encapsulated B. polyfermenticus SCD by 3% sodium alginate were investigated. Encapsulation with 0.5% methylcellulose showed the highest survival rate for 3 h in artificial gastric juice. Therefore, the optimized encapsulation material was 3% alginate with 0.5% methylcellulose. Furthermore, the survival of encapsulated B. polyfermenticus SCD was shown to be 122%, when 1% bile salt was added. Freeze-dried encapsulation resulted in lower survival than with non-dried encapsulation. Therefore, encapsulation was the most effective when 3% sodium alginate was used with 0.5% methylcellulose, but without freeze-drying.

Thin film encapsulation of thin-cathode organic electroluminescent devices

  • Lee, Shih-Nan;Hwang, Shiao-Wen;Chen, Chin H.
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.1034-1037
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    • 2006
  • We have developed a novel thin film encapsulation method for thin-cathode OLED by introducing organic (not polymer)/inorganic multiple thin films to protect device, which is shown to slow down the permeation rate of moisture and oxygen. From the stability test of devices, the projected lifetime of thin-cathode OLED device with thin film encapsulation was similarly to that with glass lid encapsulation.

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The Influence of Encapsulation Layer Incorporated into Flexible Substrates for Bending Stress (Flexible 기판의 Bending Stress에 대한 Encapsulation Layer의 영향)

  • Park, Jun-Baek;Seo, Dae-Shik;Lee, Sang-Keuk;Lee, Joon-Ung;Kim, Yong-Hoon;Moon, Dae-Gyu;Han, Jeong-In
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.473-476
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    • 2003
  • This paper shows necessity of encapsulation layer to maximite flexibility of brittle indium-tin-oxide (ITO) on polymer substrates. And, Young's modulus (E) of encapsulation layer have an significant effect on external bending stress and the coefficient of thermal expansion (CTE) of that have a significant effect on internal thermal stress. To compare magnitude of total mechanical stress including both bending stress and thermal stress, the mechanical stress of triple-layer structure (substrate / ITO / encapsulation layer or substrate / buffer layer / ITO) can be quantified and numerically analyzed through the farthest cracked island position. As a result, it should be noted that multi-layer structures with more elastic encapsulation material have small mechanical stress compared to that of buffer and encapsulation structure of large Young's modulus material when they were externally bent.

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The Effect of Encapsulation Layer Incorporated into Polymer Substrates for Bending Stress (고분자 기판의 휨 스트레스에 대한 Encapsulation층의 효과)

  • 박준백;서대식;이상극;이준웅;김영훈;문대규;한정인
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.4
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    • pp.443-447
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    • 2004
  • In this study, we investigated the necessity of encapsulation layer to maximize flexibility of brittle indium-tin-oxide (ITO) on polymer substrates. And, Young's modulus (E) of encapsulation layer han a significant effect on external bending stress and the coefficient of thermal expansion (CTE) of that han a significant effect on internal thermal stress. To compare the magnitude of total mechanical stress including both bending stress and thermal stress, the mechanical stress of triple-layer structure (substrate / ITO / encapsulation layer or substrate / buffer layer / ITO) can be quantified and numerically analyzed through the farthest cracked island position. As a result, it should be noted that multi-layer structures with more elastic encapsulation material have small mechanical stress compared to that of buffer and encapsulation structure of large Young's modulus material when they were externally bent.

Effect of PVA-Encapsulation on Hydrogen Production and Bacterial Community Structure (수소 생산과 세균 군집구조에 미치는 PVA-포괄고정화의 영향)

  • Yun, Jeonghee;Kim, Tae Gwan;Cho, Kyung-Suk
    • Microbiology and Biotechnology Letters
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    • v.42 no.1
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    • pp.41-50
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    • 2014
  • In this study, the performances of PVA-encapsulation and non-encapsulation in a fed-batch bioreactor system were compared for biohydrogen production. Hydrogen production in the PVA-encapsulation bioreactor was not significantly different in comparison to the non-encapsulation bioreactor. However, the hydrogen gas in the encapsulation bioreactor could be stably produced when it was exposed to environmental difficulties such as pH impact by the accumulation of organic acids as fermentative metabolic products. Bacterial communities by DGGE analysis were differently shifted between the PVA-encapsulation and non-encapsulation bioreactors from the initial sludge. The community of hydrogen producing bacteria was stable during the experimental period in the PVA-encapsulation bioreactor compared to the non-encapsulation method. The absolute quantitation of the DNA copy number by a high-throughput droplet digital PCR system for six genera contributed to hydrogen production showing that the numbers of dominant bacteria existed at similar levels in the two bioreactors regardless of encapsulation. In both of two bioreactors, not only Clostridium and Enterobacter, which are known as anaerobic hydrogen producing bacteria, but also Firmicutes, Ruminococcus and Escherichia existed with $1{\times}10^5-1{\times}10^6$ copy numbers of ml-samples exhibiting rapid growth during the initial operation period.

Temperature Distribution According to the Structure of a Conductive Layer during Joule-heating Induced Encapsulation for Fabrication of OLED Devices (OLED 소자 제조를 위한 주울 가열 봉지 공정 시 도전층 구조에 따르는 열분포)

  • Jang, Ingoo;Ro, Jae-Sang
    • Journal of the Korean institute of surface engineering
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    • v.46 no.4
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    • pp.162-167
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    • 2013
  • Encapsulation is required since organic materials used in OLED devices are fragile to water vapor and oxygen. Laser sealing method is currently used where IR laser is scanned along the glass-frit coated lines. Laser method is, however, not suitable to encapsulating large-sized glass substrate due to the nature of sequential scanning. In this work we propose a new method of encapsulation using Joule heating. Conductive layer is patterned along the sealing lines on which the glass frit is screen printed and sintered. Electric field is then applied to the conductive layer resulting in bonding both the panel glass and the encapsulation glass by melting glass-frit. In order to obtain uniform bonding the temperature of a conductive layer having a shape of closed loop should be uniform. In this work we conducted simulation for heat distribution according to the structure of a conductive layer used as a Joule-heat source. Uniform temperature was obtained with an error of 5% by optimizing the structure of a conductive layer. Based on the results of thermal simulations we concluded that Joule-heating induced encapsulation would be a good candidate for encapsulation method especially for large area glass substrate.

A Multi-Level Knowledge-Based Design System for Semiconductor Chip Encapsulation

  • Huh, Y.J.
    • Journal of the Microelectronics and Packaging Society
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    • v.9 no.1
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    • pp.43-48
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    • 2002
  • Semiconductor chip encapsulation process is employed to protect the chip and to achieve optimal performance of the chip. Expert decision-making to obtain the appropriate package design or process conditions with high yields and high productivity is quite difficult. In this paper, an expert system for semiconductor chip encapsulation has been constructed which combines a knowledge-based system with CAE software.

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Supramolecular Nanodevice Based on Helical Encapsulation of Photo-/Electroactive Oligomers

  • Kim, Oh-Kil
    • Proceedings of the Polymer Society of Korea Conference
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    • pp.167-167
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    • 2006
  • Photo-/electroactive donor-acceptor (D-A) chromophores were synthesized and investigated for energy- and electron-transfer (ET/eT) properties, for which the chromophores are supramolecularly integrated by encapsulation with helical amylose, rendering the chromophores aggregation-free and rigidified along the helical axis and thus, a remarkably enhanced fluorescence intensity. Fluorescence quenching studies indicated that the helical encapsulation gives the ET/eT a clear D-A distance dependence unlike with the encapsulation-free counterparts, being reflected in their florescence decay profile. Another notable difference is that the helical supramolecule of the chromophores forms a perpendicularly oriented self-assembly. Transport behavior in the solid state will be also discussed.

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