• Title/Summary/Keyword: Block composition

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Patterned Surfaces in Self-Organized Block Copolymer Films with Hexagonally Ordered Microporous Structures

  • Hayakawa Teruaki;Kouketsu Takayuki;Kakimoto Masa-alki;Yokoyama Hideaki;Horiuchi Shin
    • Macromolecular Research
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    • v.14 no.1
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    • pp.52-58
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    • 2006
  • A novel fabrication of the patterned surfaces in the polymer films was demonstrated by using the self-organizing character of the block copolymers of polystyrene-b-oligothiophenes and polystyrene-b-aromatic amide dendron. Hexagonally arranged open pores with a micrometer-size were spontaneously formed by casting the polymer solutions under a moist air flow. The amphiphilic character of the block copolymers played the crucial role as a surfactant to stabilize the inverse emulsion of water in the organic solvent, and subsequently the aggregated structure of the hydrophilic oligothiophene or aromatic amide dendron segments remained on the interiors of the micropores. The chemical composition on the top of the surface of the microporous films was characterized by energy-filtering transmission electron microscopy (EFTEM) or a time-of-flight secondary ion mass spectrometer (ToF-SIMS). The characterizations clearly indicated that the patterned surfaces in the self-organized block copolymer films with the hexagonally ordered microporous structures were fabricated in a single step.

A Study on the Application of Low-Rise and High-Density Multiple Dwelling Housing Model in Urban Individual Residential Area - Focused on Ui-dong Public Detached Housing Area - (도시단독주택지 저층고밀형 집합주택 모델의 적용에 관한 연구 - 우이동 국민주택단지를 대상으로 -)

  • Jun, Byung-Kweon
    • Journal of the Korean housing association
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    • v.22 no.3
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    • pp.101-111
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    • 2011
  • This study was conducted to investigate the indiscriminate development occuring as a result of high-density land use per lot in residential areas of Seoul, which mainly consist of detached houses. The primary goals of this study were: (1) to suggest a block unit development method as an alternative architectural method of the current uniform development, in which high-rise and high-density apartments are usually built; and (2) to check the feasibility of the suggested method. Based on the analyses of the existing block composition types of residential areas, the prerequisite planning indices for applying a collective housing model were investigated. Subsequent to applying a collective housing type within each unit block, the collective housing model was analyzed. The results of the analyses showed that indiscriminate development was rampant in detached urban houses areas, and more than 70% of the buildings constructed before the 1980s needed re-development. The feasibility of the models was investigated depending on the models of low-rise and high-density collective housing, which utilize various block arrangements such as the court type, linear type, villa type, and composite type. The results of this study showed that the newly applied low-rise and highdensity multiple dwelling housing model in urban individual residential area significantly contributed to creating a good living environment in terms of both physical and psychological aspects.

Preparation of Core-shell Type Nanoparticles of Poly($\varepsilon$-caprolactone) /Poly(ethylene glycol)/Poly( $\varepsilon$-caprolactone) Triblock Copolymers

  • Ryu, Jae Gon;Jeong, Yeong Il;Kim, Yeong Hun;Kim, In Suk;Kim, Do Hun;Kim, Seong Ho
    • Bulletin of the Korean Chemical Society
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    • v.22 no.5
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    • pp.467-475
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    • 2001
  • A triblock copolymer based on $poly(\varepsilon-caprolactone)$ (PCL) as the hydrophobic part and poly(ethylene glycol) (PEG) as the hydrophilic portion was synthesized by a ring-opening mechanism of ${\varepsilon}-caprolactone$ with PEG containing a hydroxyl group at bot h ends as an initiator. The synthesized block copolymers of PCL/PEG/PCL (CEC) were confirmed and characterized using various analysis equipment such as 1H NMR, DSC, FT-IR, and WAXD. Core-shell type nanoparticles of CEC triblock copolymers were prepared using a dialysis technique to estimate their potential as a colloidal drug carrier using a hydrophobic drug. From the results of particle size analysis and transmission electron microscopy, the particle size of CEC core-shell type nanoparticles was determined to be about 20-60 nm with a spherical shape. Since CEC block copolymer nanoparticles have a core-shell type micellar structure and small particle size similar to polymeric micelles, CEC block copolymer can self-associate at certain concentrations and the critical association concentration (CAC) was able to be determined by fluorescence probe techniques. The CAC values of the CEC block copolymers were dependent on the PCL block length. In addition, drug loading contents were dependent on the PCL block length: the larger the PCL block length, the higher the drug loading content. Drug release from CEC core-shell type nanoparticles showed an initial burst release for the first 12 hrs followed by pseudo-zero order release kinetics for 2 or 3 days. CEC-2 block copolymer core-shell type nanoparticles were degraded very slowly, suggesting that the drug release kinetics were governed by a diffusion mechanism rather than a degradation mechanism irrelevant to the CEC block copolymer composition.

A Study on the Beijing hotel's Architectural Characteristics of the Early Reform & Opening times in China - Focusing on the cases of high-rise hotels from 1978 until 1992 - (중국 개혁개방 초기 북경호텔의 건축적 특성에 관한 연구 - 1978년부터 1992년까지의 고층호텔 건축사례를 중심으로 -)

  • Gao, Yong;Kim, Hwan-Sik;Lee, Jeong-Soo
    • Korean Institute of Interior Design Journal
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    • v.19 no.2
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    • pp.197-205
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    • 2010
  • This study examines for the processes of making a architectural significant issue of 20 cases form of Beijjng's hotel through analyzing the space composition from early the 1950's to 1992 in China. In the methods of analyzing process, We study the literatures, research reports and architectural drawings including the site survey. We hope to establish the principle in morphological characteristics and space composition of Beijing's high-rise hotels through analyzing the plan of these hotels. Finally, We find out the principles after researching. Firstly, Beijing's hotels in China faced on the being difficulties through the process of national development especially in political and economical conditions of country and peoples. Consequently, size of the Beijing's hotel developed with the fact that is complicated from that is single styles focused on the medium-sized one, modernizing popularity and the high-rise hotel buildings appeared plentifully and the form appeared with tall building putting first. Secondly, there are many immanent and interlocking styles in hotel's architectural block plans, many composition styles in big sized hotels, in opposition immanent styles in small sized ones and there are many trend of concourse style in medium sized hotels. To the layout of hotel's room inside of the linear styles are many in big and medium sized hotels.

A Study on the Block Types of Urban Housing - the Case Study of the Western Housing since 70's - (도시형 집합주택의 주동 유형에 관한 연구 - 70년대 이후 서구의 집합주택사례를 중심으로 -)

  • 우동주;양재혁
    • Journal of the Korean housing association
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    • v.13 no.6
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    • pp.111-120
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    • 2002
  • The purpose of this study is to understand the trends of urban housing in the age of modernization in Western cities since 1970's, and to provide the useful data for diversifying urban housing types in Korea. Although the housing types can be categorized in many ways according to the points of view, this study classifies 11 types by a criterion of urban composition elements. Among 11 urban housing types, one type, free-standing slab structure, has been mainly applied to Korean situation. The reason might be that the free-standing structure type is the most efficient one in terms of land use and block organization, but it results in a monotonic condition of urban housing blocks. Therefore, taking local characteristics and urban contexts in Korea into consideration, the future urban housing design should be developed in different ways of making local life styles possible in them, by adopting various types of Western urban housing precedents.

Synthesis of Amphiphilic Poly(alkyl methacrylate-b-methacrylic acid) by Group Transfer Polymerization and Selective Hydrolysis

  • Soon Ki Kwon;Weon Jung Choi;Yun Hi Kim;Sam Kwon Choi
    • Bulletin of the Korean Chemical Society
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    • v.13 no.5
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    • pp.479-482
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    • 1992
  • Several poly(alkyl methacrylate-b-t-butyl methacrylate) diblock copolymers were synthesized by group transfer polymerization. The molecular weight of poly(t-butyl methacrylate) segments and the composition of the resulting block copolymers were controlled by the monomer feed ratios and mole ratios of monomer to initiator. The poly(t-butyl methacrylate) block was quantitatively hydrolyzed to poly(methacrylic acid) block by refluxing with a catalytic amount of p-toluenesulfonic acid in dioxane at $100^{\circ}C$ for 12 hrs. The thermogravimetric analysis of poly(alkyl methacrylate-b-t-butyl methacrylate) exhibited the lose of isobutylene and subsequent anhydride formation in the range of $205-300^{\circ}C$.

A Study on Water Purification Effect of Media Block Using Porous Ceramics and Zeolite (다공성 세라믹과 제올라이트를 활용한 수질정화미디어블럭의 효과 연구)

  • Jeon, Sung-yool;Koo, Bon-hak
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.20 no.5
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    • pp.59-66
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    • 2017
  • Preeminent water treatment plans are essential to preserve the water quality of aquatic biotopes. Previous studies have not been sufficient to provide cost-effective maintenance method since they focused only on the purification of deteriorated water that requires a continuous supply of clean water. This study proposes an economical method of water quality maintenance using water treatment media block constructed vertically using porous ceramics, zeolite, and river pebble. The water treatment media block does not require a separate purification area because it functions as a purifier within the ecological pond which can maximize the biotope area. To evaluate the performance of the water treatment media block, we longitudinally tracked the change of water quality indicators (pH, TDS, COND, DO, T-P, T-N, COD) suggested by Water Environment Standards, Ministry of Environment, Republic of Korea. We compared the water quality of one control (A: general ecological pond composition method of the laminated structure) and two experimental groups (B: a combination of aquatic plants and a water treatment media block, C: a water treatment media block only). As a result, we confirmed that the water treatment media block is an efficient and economical method to maintaining the water quality of the ecological pond for a long time. The water treatment media block will be a great help in providing a better aquatic biotope space for aquatic insects and fishes living in clear water.

The Influence of Community Facilities on the Price of Housing with Block Unit on the Price of Housing with Block Unit: Focused on 82 Complexes in the Seoul Metropolitan Area (블록단위 단독주택의 주민공동시설이 가격에 미치는 영향에 관한 연구: 수도권 82개 단지를 중심으로)

  • Kim, Ji-Hun;Jo, Hang-Hun
    • Land and Housing Review
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    • v.11 no.3
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    • pp.1-9
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    • 2020
  • This study fulfills an empirical analysis how the physical factors affect the formation of housing price with the block unit. Block unit houses are a type of housing that pursues comfort and convenience in that the characteristics of individual houses and apartment houses are mixed. Existing studies have focused only on the physical characteristics of various planning elements such as block-type residential complexes. Nevertheless, it is not known whether the physical characteristics of block-type residential complexes reflect the preferences of actual consumers. In addition, there are no sufficient studies on how to evaluate them from the market side. In this study, block-level detached housing sites the target complexes with 10 or more households built between 2002 and 2019. The target areas for analysis are 163 complexes in Paju, Namyangju, Goyang, Suwon, Yongin, Ansan, Gimpo, Incheon, Seongnam, Hwaseong and Gwangju, Gyeonggi-do. The physical elements that make up the unit housing were classified through factor analysis. Finally, regression analysis was conducted to establish the basis determining the price-forming factors. As a result of the analysis, the factors that influenced the price were the site area and the number of community facilities. The variable with negative influence was the distance from Seoul. Based on the results of this study, it can be said that the influence on price formation in various areas was confirmed by presenting the relationship between the facility composition and price of a detached house.

Synthesis and Characterization of Linear and Star-shaped Poly(lactic acid) Stereo-block Copolymers (선형 및 스타형 폴리락트산 입체블록 공중합체의 합성 및 물성)

  • 이선영;김지흥
    • Polymer(Korea)
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    • v.24 no.5
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    • pp.638-645
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    • 2000
  • Linear and star-shaped, poly(lactic acid) (PLA) stereo-block copolymers were synthesized by sequential polymerization of DL-lactic acid and L-lactide in the presence of diol or polyol compounds. The molecular weight of block copolymers could be controlled to some extent by the variation of alcohol content. These block copolymers had relatively narrow molecular weight distributions. The glass transition temperature and melting temperature of block copolymers appeared at around 5$0^{\circ}C$ and 100~14$0^{\circ}C$, respectively. The block copolymers were found to crystallize even at the high D-stereoisomer concentration of 35 mol%, in contrast to the amorphous nature of the random copolymer with similar composition. Also we could observe the crystallinity of PLA stereo-block copolymers varying with annealing temperature and time.

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An Analysis of Mario Botta's residential design (Mario Botta 주거 건축의 특성 분석)

  • 조희라
    • Journal of the Korean housing association
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    • v.12 no.4
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    • pp.195-203
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    • 2001
  • The purpose of this study is to analyze the characteristics of Mario Botta's residential design. The characteristics of Mario Botta's residential design are following as : 1. The residential design of Mario Botta planed from 1960' to 1970's is based on the style composition method of modern design, specially by the influence of Le Corbusier and Louis I. Kahn. Botta's residential design of the 1980's is generally affected by A. Palladio, and is characterized as the representation of classic standard. The residential design of the 1980's shows the establishment level of Mario Botta's residential design, and produces particular Botta's facade. 2. The characteristics of Mario Botta's spatial composition on residential design could be implicated by the spatial distribution of each floor which is divided by three floors, simple and primitive volume which has a symmetry, opening through the massive elimination n the center of front, double skin, the contrast between void and solid, and the inflow of light through the top-light. 3. Most Botta's residential designs have Loggia in the center of facade working as a buffer space which joins outside and inside space together. They also lead the spatial continuous flow. The inside space is combined by the light coming through top-light and vertical opening. 4. They have high accomplishment in complicating details. They show the outside design of a horizontal belt according to the module of concrete block and the decorated design using compositional materials such as an unevenness piled up askew concrete block .

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