• Title/Summary/Keyword: organic molecules

Search Result 529, Processing Time 0.029 seconds

Polymeric Materials for Molecular Recognition

  • Ki, Chang-Do;Lee, Kang-Won;Chang, Ji-Young
    • Proceedings of the Polymer Society of Korea Conference
    • /
    • 2006.10a
    • /
    • pp.172-172
    • /
    • 2006
  • Molecular imprinting constitutes a valuable method of preparing polymeric materials with specific binding properties. The most conspicuous merit of molecular imprinting is that structurally three-dimensional recognition sites can be introduced into a polymer matrix with ease and low cost when compared with the complicated process of biological system for antigen and antibody. We used a thermally reversible bond for the preparation of the monomer-template complex, which allowed us to remove the template easily by means of a simple thermal reaction and to simultaneously introduce various functional groups into the cavity. This method is especially propitious for developing artificial receptors for molecules lacking strongly interactive groups.

  • PDF

Mechanism of Organogel Formation from Mixed-Ligand Silver (I) Carboxylates

  • Kim, Ji-Yeon;Park, Cheol-Hee;Kim, Sang-Ho;Yoon, Sung-Ho;Piao, Longhai
    • Bulletin of the Korean Chemical Society
    • /
    • v.32 no.9
    • /
    • pp.3267-3273
    • /
    • 2011
  • Ag(I) carboxylate gelators with mixed-ligands were systemically investigated to understand the mechanism of the organic gel formation. The gelators constructed 3-D networks of nanometer-sized thin fibers which facilitated gel formation in various aromatic organic solvents, even at very low concentrations. The loss of reflection peaks in the X-ray diffraction data indicated the reduction of strong interactions between the long alkyl chains as the Ag(I) carboxylates formed gels by maximizing their interactions with the organic solvents. The gelation temperature ($T_{gel}$) was measured to explore the interaction between the gelator molecules and solvents depending on their composition and concentration. Based on the gelation phenomena, a dissociation/re-association mechanism was proposed.

A study on Electrical and Optical Properties of Organic Electroluminescent Devices using various Substrates (기판 종류에 따른 유기전기발광소자의 전기적.광학적 특성에 관한 연구)

  • Cho, Jae-Young;Kim, Jung-Yeoun;Kim, Jong-Jun;Oh, Hwan-Sool
    • Proceedings of the IEEK Conference
    • /
    • 2000.11b
    • /
    • pp.25-28
    • /
    • 2000
  • In this paper, three types of organic electroluminescent devices(OELD) were fabricated on mechanically flexible plastic substrate by using vacuum deposition method. The devices consist of a hole transporting material such as TPD, a light-emitting material such as Alq$\sub$3/ and an electron transporting material, blocking material such as PBD. Electrical and optical properties of these OELDs were measured. This paper shows that organic small molecules based on OELD can be successfully deposited on a flexible plastic substrate. This points open the potential for low cost mass production of flexib]e displays, including roll to roll processing.

  • PDF

Light emitting thin film structures based on organic luminophors embedded in porous alumina matrixes

  • Gorokh, G.G.;Labunov, V.A.;Smirnov, A.G.;Kukhta, A.V.
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2002.08a
    • /
    • pp.315-318
    • /
    • 2002
  • Light emitting thin film structures based on organic luminophors embedded in porous alumina matrixes are discussing. The optical properties of the luminophors in a matrix differ greatly from their properties in usual crystalline state or in a solution and they depend on the concentration of luminophors molecules of up to 10-2 mol/l. Successful experiments on filling of pores with organic luminophors and the investigation of their luminescent and optical properties were carried out.

  • PDF

Effect of Dodecane on the Surface Structure and the Electronic Properties of Pentacene on Modified Si (001)

  • Kim, Beom-sik;Kang, Hee Jae;Seo, Soonjoo;Park, Nam Seok
    • Applied Science and Convergence Technology
    • /
    • v.25 no.2
    • /
    • pp.28-31
    • /
    • 2016
  • The structural and the electronic properties of pentacene on modified Si (001) were investigated using scanning tunneling microscopy (STM), atomic force microscopy (AFM) and ultraviolet photoelectron spectroscopy (UPS). Dodecane was used to modify Si (001) substrates and then pentacene was deposited on dodecane/Si (001). Our STM results show a uniform distribution of aggregated dodecane molecules all over the clean Si (001). The surface structure of pentacene on dodecaene/Si (001) examined by AFM is analogous to that of pentacene on $SiO_2$. The UPS data showed that the work function of pentacene on clean Si (001) and pentacene on modified Si (001) with dodecane was 6.41 and 5.57 eV, respectively. Our results prove that dodecane results in the work function difference between pentacene on clean Si (001) and pentacene on dodecane/Si (001).

Role of KOH in the One-Stage KOH Activation of Cellulosic Biomass

  • Oh, Gyu-Hwan;Yun, Chang-Hun;Park, Chong-Rae
    • Carbon letters
    • /
    • v.4 no.4
    • /
    • pp.180-184
    • /
    • 2003
  • The role of KOH in the one-stage KOH-activation of rice straws was studied using FTIR, XPS, TGA, and DTG techniques. It was found that at the impregnation, KOH extracts to some extent the lignin component from rice straw and reacts with hydroxyl groups. On heat-treatment, the impregnated KOH facilitates intermolecular condensation reaction on one hand but retards the thermal degradation of cellulose molecules on the other hand. The oxygen-containing surface functional groups newly created by oxidation of KOH may facilitate the bulk, not controlled, consumption of carbon atoms so that the effective porosities may not be able to be developed by the one-stage activation process.

  • PDF

Application of Home-made Capillary Zone Electrophoresis System to the Separation of Organic Molecules (제작된 모세관 전기영동 시스템의 유기물 분석에의 응용)

  • Kong Joo Lee;Gwi Suk Heo
    • Journal of the Korean Chemical Society
    • /
    • v.35 no.3
    • /
    • pp.219-225
    • /
    • 1991
  • Capillary zone electrophoresis (CZE) which is highly efficient separation technique has been domestically established having optimum detection sensitivity. By applying 20∼35 kV of electric potential to the narrow (50 ${\mu}m$ i.d.) capillary tubing filled with running buffer, this technique can quickly (< 20 min) separate the small quantities of sample with high separation efficiency (number of theoretical plates : 200,000∼500,000). Factors affecting the separation efficiency and resolution in CZE were examined by analyzing adenine and catecholamine derivatives.

  • PDF

Electronic Structure of the Tris(8-quinolinolato)aluminum (III) ($Alq_3$) / Ba Interfaces and Light Out-coupling Characteristics of Organic Light-emitting Diodes Based on these Interfaces

  • Kwon, Jae-Wook;Lim, Jong-Tae;Yeom, Geun-Young
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.834-836
    • /
    • 2009
  • We investigated the device performance for organic light-emitting characteristics based on the electron-injecting interfacial characteristics of Ba deposited on tris(8-quinolinolato)aluminum (III) ($Alq_3$) with a change of a Ba coverage. The device performance of organic light-emitting diodes with Ba coverage of 1 nm significantly improved by the lowering of the electron-injecting barrier height that was induced by electronic charge transfer. However, the device with Ba coverage above 1 nm showed poor device performance. The spectroscopic results indicated that the $Alq_3$ molecules started to decompose by the reaction between Ba and the phenoxide moiety of the molecule.

  • PDF

Effects of Metal-Organic Framework Membrane on Hydrogen Selectivity

  • Suh, Jun Min;Cho, Sung Hwan;Jang, Ho Won
    • Journal of Sensor Science and Technology
    • /
    • v.29 no.6
    • /
    • pp.374-381
    • /
    • 2020
  • Hydrogen gas has attracted considerable attention as a promising candidate for future energy resources because of its eco-friendly characteristics; however, its highly combustible characteristics should be thoroughly examined to preclude potential disasters. In this regard, a highly sensitive method for the selective detection of H2 is extremely important. To achieve excellent H2 selectivity, the utilization of a metal-organic framework (MOF) membrane can physically screen interfering gas molecules by restricting the size of kinetic diameters that can penetrate its nanopores. This paper summarizes the various endeavors of researchers to utilize the MOF molecular sieving layer for the development of highly selective H2 sensors. Further, the review affords useful insights into the development of highly reliable H2 sensors.

Synthesis and Characterization of DNA-Templated Nanostructures: Toward Molecular Electronics

  • Lee, Jeong-Gyu
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.08a
    • /
    • pp.92.1-92.1
    • /
    • 2013
  • Molecular electronics has been the subject of intese research for many years because of the fundamental interest in molecular charge transport and potential applications, such as (bio)nanosensors and molecular memory devices. Molecular electronics requires a method for making reliable eletrical contacts to singlemolecules. To date, several approaches have been reported: scanning-probe microscopy, mechanical break junctions, nano patterning, and direct deposition of electrode on a self-assembled monolayers. However, most methods are laborious and difficult for large-scale application and more importantly, cannot control the number of moleucles in the junction. Recently, DNA has been used as a template for metallic nanostructures (e.g., Ag, Pd, and Au nanowires) through DNA metallization process. Furthermore, oligodeoxynucleotides have been tethered to organic molecules by using conventional organic reactions. Collectively, these techniques should provide an efficient route toward reliable and reproducible molecular electronic devices with large-scale fabrication. Therefore, I will present a paradigm for the fabrication of moleuclar electronic devices by using micrometer-sized DNA-singe organic molecule and DNA triblock structures.

  • PDF