• Bulletin of the Korean Chemical Society
• /
• v.18 no.2
• /
• pp.198-203
• /
• 1997

Two different carbazolylnitrostilbene chromophores with second-order nonlinear optical (NLO) activity were newly synthesized by the reaction of 9-(2-hydroxyethyl)-9H-carbazol-3-carbaldehyde with 4-nitrophenylacetonitrile or 4-nitrophenylacetic acid. The NLO monomers were obtained by reaction of these chromophores with methacryloyl chloride. The side-chain nonlinear optical polymers were synthesized by the copolymerization of NLO monomer with methylmethacrylate using a free radical initiator. The chemical structures of the polymers were identified by spectroscopic means and the polymer properties such as molecular weight, Tg, solubility, UV-visible absorption, and second-harmonic generation (SHG) coefficients were investigated.

• Bulletin of the Korean Chemical Society
• /
• v.19 no.11
• /
• pp.1165-1168
• /
• 1998

2-Tetrahydropyranyl methacrylate with a self-crosslinkable moiety was copolymerized with methyl methacrylate and 4-[(2-methacryloxyethyl)methylamino]-4'-nitrostilbene or 4-[(2-methacryloxyethyl)ethylamino]-4'nitroazobenzene to provide second-order nonlinear optical property. Glass transition temperatures (Tg of the copolymers are around 140 ℃. The copolymers were soluble in common organic solvents such as tetrahydrofuran (THF), cyclohexanone, and N,N-dimethylformamide (DMF). Poling was carried out at 140 ℃ for 20 min and identified with UV-Vis spectroscopy. Electro-optic coefficient (r33) of copolymer was 62 pm/V for polymer 2 at 633 nm, and relaxation did not remarkably occur due to the formation of a crosslinked network at 200 ℃ for 15 min.

• Bulletin of the Korean Chemical Society
• /
• v.19 no.11
• /
• pp.1168-1171
• /
• 1998

Two kinds of second-order nonlinear optical copolymers were prepared by the copolymerization of the vinyl monomers containing NLO chromophore, methacrylic acid, and methyl methacrylate or butyl methacrylate. Glass transition temperatures (Tg of copolymers were around 130 ℃. The copolymers were soluble in common organic solvents such as tetrahydrofuran (THF), cyclohexanone, and N,N-dimethylformamide (DMF). The crosslinked copolymer was obtained by thermal treatment using pentaerythritol tetrakis(2-mercaptoacetate) as a crosslinker and became insoluble in tetrahydrofuran (THF) and N,N-dimethylformamide (DMF). Poling was carried out at 120 ℃ for 20 min and identified with UV-Vis spectroscopy. Electro-optic coefficient (r33) measurement showed a value of 35 pm/V for polymer 2 at 633 nm. Temporal stability of copolymers was improved owing to the crosslinked network, which was successfully obtained at 170 ℃ for 30 min after poling.

• Korean Institute of Interior Design Journal
• /
• v.16 no.2 s.61
• /
• pp.155-162
• /
• 2007

The purpose of this comparative study is to analyze the characteristics of art museums of Louis I. Kahn. Kahn's main architectural thoughts of 'what it wants to be' and 'how it was done' act as a basis for this research. 'What it wants to be' means the existence of architecture and relates to the concept of 'room'. 'How it was done' shows the tectonic aspects of architecture and construction process to enhance its presence. Detailed items from these two thoughts applied to clarify the order in dynamics, the visualization of construction process, and the relationship between structure and light in the space of Kahn's art museums. Yale university art gallery was the first major project of Kahn and he showed tectonic characters through tetrahedral concrete slab. The unity of structure, space and light can be found in the Kimbell art museum through the vaulted structural unit. Yale center for British art is the best example of the concept of 'room' and 'tectonic' because it clearly shows the unity of spatial and structural system, and their relation to light. As a result, this study tries to find out that Kahn had consistently developed his thoughts of'room' and 'tectonic', and tried to keep them in his art museum designs.

• Korean Institute of Interior Design Journal
• /
• v.14 no.5 s.52
• /
• pp.89-97
• /
• 2005

The purpose of this study is to analyze the interior characteristics of Philips Exeter Academy library by Louis I. Kahn. Kahn's main thoughts of 'what it wants to be ' and 'how it was done' play a important role in this research because these statements act as a clue to understand this library. 'What it wants to be' means the essence and existence of architecture and 'how it was done' shows the tectonic of architecture and construction process to enhance its presence. Most of his works inform that Kahn had consistently applied his thoughts into design process. The thoughts of the essence of library leads Kahn to configurate 3 layers of interior space. The emphasis of tectonic expression is also the characteristics of interior in that structure is the logical part of whole building system rather than concealing object for the exterior of buildings. In Exeter library, interior characteristics are summarized as 3 layers of interior configuration, the order in dynamics, the visualization of construction process, and the relationship between structure and space.

• Korean Institute of Interior Design Journal
• /
• v.17 no.1
• /
• pp.69-76
• /
• 2008

The purpose of this study is to analyze the interior characteristics of the Yale center for British art by Louis I. Kahn. As his last realized project, the Yale center for British art shows Kahn's latter architectural thoughts about exterior/interior, space/structure and theory/practice. Kahn arranged unit space(room) around two interior courts and laminated them vertically. This spatial configuration is the result of solving the urban context which needed the continuity of street and complicated program including art museum, retail shop, studio and library. Although Kahn adpted severe formal configuration, he added changes to spatial relation. The visualization of architectural system is realized by revealing the relation of the unit space and structure. And this emphasized the presence of the center. The emphasis of tectonic expression is also the characteristics of interior in that structure is the logical part of whole building system rather than concealing object for the exterior of buildings. In the Yale center for British art, interior characteristics are summarized as spatial configuration based on the relation between unit space and two courts, the visualization of structural order, and the relationship between structure and light.

• Journal of the Korean Chemical Society
• /
• v.22 no.6
• /
• pp.380-385
• /
• 1978

Adsorption isotherms of o-xylene on Spheron 6, a graphitized carbon black, are obtained at various temperatures using a quartz beam microbalance. BET plots are made to estimate the molecular area of o-xylene from these isotherms. On Spheron 6, the molecular area of o-xylene (m.p $-25^{\circ}C$) remains constant until the temperature is increased up to $-15^{\circ}C$, but increases abruptly between $-15^{\circ}C$ and $-14^{\circ}C$, and then again remains constant thereafter. These results are interpreted as implying that the adsorbed o-xylene molecules are flatly localized on Spheron 6 with compact packing below $-15^{\circ}C$ while they gain a rotational degree of freedom around the benzene ring at the higher temperature.

• Korean Institute of Interior Design Journal
• /
• v.15 no.2 s.55
• /
• pp.73-80
• /
• 2006

The purpose of this study is to analyze the characteristics of structural expression in the works of Louis I. Kahn. Kahn's main architectural thoughts of 'what it wants to be' and 'how it was done' are important in this research because these statements act as a clue to understand the relationship between structural expression and space. 'What it wants to be' means the essence and existence of architecture and 'how it was done' shows the tectonic of architecture and construction process to enhance its presence. Kahn's emphasis of structural expression stems from the fact that structure is the logical part of whole building system rather than the concealed object for the exterior of buildings. Therefore structure of Kahn's architecture is not a structure only to support building but a mean to express his thoughts in a corporeal way. In Kahn's works, the characteristics of structural expressions are summarized as the visualization of the order in dynamics, construction process, spatial system, and the relationship between structure and light in the space.

• Korean Institute of Interior Design Journal
• /
• v.21 no.6
• /
• pp.168-176
• /
• 2012

The aim of this study is to review the meaning of technologies in the works of Louis I. Kahn. Kahn's main architectural thoughts of 'what it wants to be' and 'how it was done' are important in this research because these statements represent the ontology of his architecture and tectonic characteristics. These divisions also can be effective in studying relationship between technology and his architecture. 'What it wants to be' means the essence and existence of architecture and 'how it was done' shows the tectonic of architecture and construction process to enhance its presence. Kahn used technology as solutions for partial problems in his early years but later he changed its role as media to realize his concept ideally. He considered technology as enhancing building's existence rather than its functional and economical efficiency. Kahn also visualize the usage of technology through detail and construction process. He developed his technology in 'application-modification-complement' process as he executed projects over again. As a result, technology itself cannot drive Kahn's architectural thoughts in a certain way but Kahn emphasized technology as media to enhance the presence of his architecture and to present visualization and realization of his concepts.

• Korean Institute of Interior Design Journal
• /
• v.18 no.3
• /
• pp.39-46
• /
• 2009

The purpose of this study is to analyze the meaning of 'dis-joint' in the works of Louis I. Kahn. Kahn tried to realize his main architectural thoughts of 'what it wants to be' and 'how it was done' through his whole life. The concept of 'dis-joint' had been developed to visualize his architectural thoughts. Kahn used' dis-joint' to show and emphasize the structural system for the raison d'etre of building. Kahn's 'dis-joint' can be categorized as 'spacing', 'butt', 'slit' and 'protrusion'. Kahn used this kind of unusual way of joint beyond simple exposure to stress the existence of element, part and building itself. Through variable combination usage of 'dis-joint', Kahn can realize his architectural thoughts into building in a concrete way. The efficiency and function of joint is not the main issue in his works. 'Dis-joint' was the concrete tool to show the tectonic of architecture and construction process to enhance its presence. Therefore 'dis-joint' of Kahn's architecture is not a joint only to combine building parts but a concrete mean to realize his thoughts in a corporeal way. These facts insinuate that Kahn's architectural philosophy is based on the thoughts of tectonic and its realization.