• 제목/요약/키워드: Molecular Surface

검색결과 2,077건 처리시간 0.038초

The rheology of two-dimensional systems

  • Fuller, G.;Yim, K.S.;Brooks, C.;Olson, D.;Frank, C.
    • Korea-Australia Rheology Journal
    • /
    • 제11권4호
    • /
    • pp.321-328
    • /
    • 1999
  • This paper discusses the rheology of complex interfaces comprised of amphiphilic materials that are susceptible to flow-induced orientation and deformation. The consequence of the coupling of the film micro-structure to flow leads to nonlinear rheology and surface fluid dynamics. Experimental methods designed to determine the mechanical rheological material functions of fluid-fluid interfaces as well as local, molecular and morphological responses are presented. These include a newly developed interfacial stress rheometer, flow ultraviolet dichroism, and Brewster-angle microscopy. These techniques are applied to a number of complex interfaces ranging from low molecular weight amphiphiles to polymer monolayers. Nonlinear flow phenomena ranging from two-dimensional nematic responses to highly elastic surface flows that manifest surface normal stress differences and elongational viscosities are described.

  • PDF

Expression of major piroplasm protein(p33)of Theileria sergenti (Korean isolate) and its immunogenicity in guinea pigs

  • Kang, Seung-Won;Kweon, Chang-Hee;Choi, Eun-Jin;Yoon, Yong-Dhuk
    • Parasites, Hosts and Diseases
    • /
    • 제37권4호
    • /
    • pp.277-283
    • /
    • 1999
  • To investigate the development of a subunit vaccine against theileriosis in cattle, the DNA fragments encoding piroplasm surface protein (p33) of Theileria sergenti of a Korean isolate were expressed in baculoviruses. The expressed p33 was characterized by indirect fluorescent antibody (IFA) and western blotting analysis. The expression of p33 was mainly detected on the surface of infected Sf21 cells by IFA. The immunoblotting analysis revealed the presence of a same molecular weight protein band of p33. The antigenicity of expressed polypeptide was further examined through the inoculation of a guinea pig. The sera of guinea pigs immunized with p33 expressed cell Iysate showed similar fluorescent antibody patterns and reacted with the same molecular weight protein of T. sergenti in immunoblotting analysis, thus indicating that this protein can be a promising candidate for a subunit vaccine in the future.

  • PDF

Fabrication of Hybrid Films Using Titanium Chloride and 2,4-hexadiyne-1,6-diol by Molecular Layer Deposition

  • 윤관혁;성명모
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
    • /
    • pp.418-418
    • /
    • 2012
  • We fabricated a new type of hybrid film using molecular layer deposition (MLD). The MLD is a gas phase process analogous to atomic layer deposition (ALD) and also relies on a saturated surface reaction sequentially which results in the formation of a monolayer in each sequence. In the MLD process, polydiacetylene (PDA) layers were grown by repeated sequential surface reactions of titanium tetrachloride and 2,4-hexadiyne-1,6-diol with ultraviolet (UV) polymerization under a substrate temperature of $100^{\circ}C$. Ellipsometry analysis showed a self-limiting surface reaction process and linear growth of the hybrid films. Polymerization of the hybrid films was confirmed by infrared (IR) spectroscopy and UV-Vis spectroscopy. Composition of the films was confirmed by IR spectroscopy and X-ray photoelectron (XP) spectroscopy. The titanium oxide cross-linked polydiacetylene (TiOPDA) hybrid films exhibited good thermal and mechanical stabilities.

  • PDF

Low Temperature Encapsulation-Layer Fabrication of Organic-Inorganic Hybrid Thin Film by Atomic Layer Deposition-Molecular Layer Deposition

  • 김세준;김홍범;성명모
    • 한국진공학회:학술대회논문집
    • /
    • 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
    • /
    • pp.274-274
    • /
    • 2013
  • We fabricate encapsulation-layer of OLED panel from organic-inorganic hybrid thin film by atomic layer deposition (ALD) molecular layer deposition (MLD) using Al2O3 as ALD process and Adipoyl Chloride (AC) and 1,4-Butanediamine as MLD process. Ellipsometry was employed to verify self-limiting reaction of MLD. Linear relationship between number of cycle and thickness was obtained. By such investigation, we found that desirable organic thin film fabrication is possible by MLD surface reaction in monolayer scale. Purging was carried out after dosing of each precursor to eliminate physically adsorbed precursor with surface. We also confirmed roughness of the organic thin film by atomic force microscopy (AFM). We deposit AC and 1,4-Butanediamine at $70^{\circ}C$ and investigated surface roughness as a function of increasing thickness of organic thin film. We confirmed precursor's functional group by IR spectrum. We calculated WVTR of organic-inorganic hybrid super-lattice epitaxial layer using Ca test. WVTR indicates super-lattice film can be possibly use as encapsulation in flexible devices.

  • PDF

Synthesis and Surface Derivatization of Processible Co Nanoparticles

  • Lee, Jin-Kyu;Choi, Sung-Moon
    • Bulletin of the Korean Chemical Society
    • /
    • 제24권1호
    • /
    • pp.32-36
    • /
    • 2003
  • Co nanoparticles were prepared by the reverse micelle technique (NaBH₄reduction of cobalt chloride in a reversed micelle solution of didodecyldimethylammoniumbromide (DDAB)/toluene). The size and the shape of Co nanoparticles could be easily controlled by changing the water contents and micelle concentrations, and the solubility of Co nanoparticles was systematically tuned by choosing appropriate surface capping organic ligand molecules. Furthermore, a novel nanofabrication process was clearly demonstrated, which generated oxide over-coated Co nanorods from Co nanoparticles in organic solution by slow oxidation with an external magnetic field.

MOF-5 계열 화합물의 수소 흡착 용량 예측에 관한 분자모델링 연구 (Molecular Modeling Studies on the Functionalized MOF-5)

  • 김대진;이태범;최승훈;이은성;오유진;윤지혜;김자헌
    • 한국전기화학회:학술대회논문집
    • /
    • 한국전기화학회 2004년도 수소연료전지공동심포지움 2004논문집
    • /
    • pp.287-292
    • /
    • 2004
  • In order to understand the relationship between molecular structure of Metal-Organic Framework(MOF) and capacity of hydrogen absorption, quantum mechanical calculations and grand canonical Monte Carlo simulations have been carried out on a series of MOF-5 having various organic linkers. The calculation results about specific surface area and electron density for various frameworks indicated that the capacity of the hydrogen storage is largely dependent on effective surface area rather than the free volume. Based on the iso-electrostatic potential surface from density functional calculation and the amount of adsorbed hydrogens from grand canonical Monte Carlo calculation, it was also found that the electron localization ground organic linker plays an important role in hydrogen capacity of MOFs.

  • PDF

Surface Morphology of AlSb on GaAs Grown by Molecular Beam Epitaxy and Real-time Growth Monitoring by in situ Ellipsometry

  • Kim, Jun Young;Lim, Ju Young;Kim, Young Dong;Song, Jin Dong
    • Applied Science and Convergence Technology
    • /
    • 제26권6호
    • /
    • pp.214-217
    • /
    • 2017
  • AlSb is a promising material for optical devices, particularly for high-frequency and nonlinear-optical applications. We report the effect of growth temperature on structural properties of AlSb grown on GaAs substrate. In particular we studied the surface of AlSb with the growth temperature by atomic force microscopy, and concluded that optimized growth temperature of AlSb is $530^{\circ}C$. We also show the result of real-time monitoring of AlSb growth by in situ ellipsometry. The results of the structural study are good agreement with the previous reported ellipsometric data.

Characterization of Surface Films Formed Prior to Bulk Reduction of Lithium in Rigorously Dried Propylene Carbonate Solutions

  • 창석균;이효중;강헌;박수문
    • Bulletin of the Korean Chemical Society
    • /
    • 제22권5호
    • /
    • pp.481-487
    • /
    • 2001
  • Surface films formed prior to bulk reduction of lithium have been studied at gold, platinum, and copper electrodes in rigorously dried propylene carbonate solutions using electrochemical quartz crystal microbalance (EQCM) and secondary ion mass spectrometry experiments. The results indicate that the passive film formation takes place at a potential as positive as about 2.0 V vs. Li/Li+ , and the passive film thus formed in this potential region is thicker than a monolayer. Quantitative analysis of the EQCM results indicates that electrogenerated lithium reacts with solvent molecules to produce a passive film consisting of lithium carbonate and other compounds of larger molecular weights. The presence of lithium carbonate is verified by SIMS, whereas the lithium compounds of low molecular weights, including lithium hydroxide and oxide, are not detected. Further lithium reduction takes place underneath the passive film at potentials lower than 1.2 V with a voltammetric current peak at about 0.6 V.

알루미늄 덩어리를 사용한 알루미늄 성장에 관한 분자동력학 연구 (Molecular Dynamics study of Aluminum growth using Aluminum Cluster Deposition)

  • J.W. Kang;K.R. Byun;W.H. Mun;E.S. Kang;H.J. Hwang
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2000년도 하계종합학술대회 논문집(2)
    • /
    • pp.306-309
    • /
    • 2000
  • In this work, we investigated A1 cluster deposition on Al (100) surface using molecular dynamics simulation. A result of simulations showed that large cluster with low energy was proper for good surfaced-films without craters at the low temperatures. We investigated the maximum substrate temperature and the time taken for substrate temperature to reach its maximum as a function of cluster size in the case of the same total energy and in the case of the same energy Per atom. The correlated collisions play an important role in interaction between energetic cluster and surface, and as cluster size and cluster energy increases, the correlated collisions effect affects interaction between energetic cluster and surface.

  • PDF

BAM을 이용한 L막의 상전이 현상과 유기초박막의 미세구조에 관한 연구 (A Study on the Microstructure of Organic Ultra Thin Films and Phase Transition of Langmuir Films in BAM)

  • 김병근;전동규;김영근;이경섭
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
    • /
    • pp.938-941
    • /
    • 2003
  • It is well known that the state of existence of molecules on the surface of water changes during compression of the molecules. Electric methods, such as measurement of the surface potential or displacement current are also useful for investigating dynamic changes of molecular state on the water surface during compression and Transformation of molecular film occurs only usually in air-water interface, 2 dimensions domain's growth and crash are achieved. Organic thin film that consist of growth of domain can understand correct special quality of accumulation film supplying information about fine structure and properties of matter of device observing information and so on that is surface forward player and optic enemy using AFM one of SPM application by nano electronics. In this paper Langmuir (L) that is one of basis technology to manufacture of organic matter device using biology material PBDG that is kind of polypeptide that have biology adaptedness. The Experiment method used ${\pi}-A$ isotherm and BAM(Brewster Angle Microscopy), using the BAM, we can to the molecular orientation of monolayer on the water surface and directly see the morphology of the films on water subphase as well as that of the films.

  • PDF