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Monolayer Films (monolayer + film)
Selected AbstractsIn,Situ Microstructure Control of Oriented Layered Double Hydroxide Monolayer Films with Curved Hexagonal Crystals as Superhydrophobic Materials,ADVANCED MATERIALS, Issue 23 2006H. Chen Oriented NiAl-layered double hydroxide (LDH) films with micro-/nanometer scale binary structures are prepared by in,situ crystallization, without using any external aluminum source or shape-directing surfactant, on a porous anodic alumina/aluminum substrate. The NiAl-LDH film structures can be controlled by tuning crystallization temperature and time. Facile hydrophobic modification of the film surface leads to superhydrophobicity, as shown in the figure. [source] One-Nanometer-Thick Seed Layer of Unilamellar Nanosheets Promotes Oriented Growth of Oxide Crystal Films,ADVANCED MATERIALS, Issue 2 2008T. Shibata Room-temperature fabrication of an ultimately thin seed layer using 2D oxide nanosheets is demonstrated. Flat nanosheets are tiled to form a highly organized monolayer with a thickness of ca. 1 nm on a glass substrate (see figure). Monolayer films of nanosheets such as Ca2Nb3O10 (2D square lattice) and MnO2 (2D hexagonal) successfully promote oriented film growth of oxide crystals such as SrTiO3 (cubic), TiO2 (tetragonal), and ZnO (hexagonal). [source] Intermolecular band dispersion in highly ordered monolayer and multilayer films of pentacene on Cu(110)PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 5 2008Hiroyuki Yamane Abstract We report the electronic structure and the charge transport mechanism of highly ordered films of pentacene on Cu(110) surface studied by angle-resolved ultraviolet photoemission spectroscopy using synchrotron radiation. For a flat-lying monolayer film, we observed the evidences of (i) formation of the interface states and (ii) two-dimensional intermolecular band dispersion of the resultant interface states, which may originate from the hybridization between the molecular orbi-tals and the wave function of the substrate. For an upright-standing multilayer film, we observed the two-dimensional intermolecular band dispersion, which originates from the intermolecular ,,, interaction. The observed effective masses of the hole for different azimuths demonstrate the presence of the anisotropy of the hole mobility in pentacene crystals also at higher temperatures. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effect of Fullerene on Photocurrent Performance of 6- O -Porphyrin-2,3-di- O -stearoylcellulose Langmuir-Blodgett FilmsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 12 2008Keita Sakakibara Abstract Thin films consisting of 6- O -porphyrin-2,3-di- O -stearoylcellulose (H2PCS) and fullerene (C60) were fabricated for anodic photocurrent generation systems by the Langmuir-Blodgett (LB) technique. The , -complexation between the porphyrin moiety and C60 in the LB films was investigated by means of the surface pressure (,)-area (A) isotherms, UV-vis, and fluorescence spectroscopy. The photocurrent density generated from the H2PCS,C60 LB monolayer films exhibited an increase with increasing the C60 proportion and reached a maximum at a mixing ratio of 1:2, yielding a quantum yield of 12.5% and an IPCE (incident photon-to-current efficiency) of 0.50% at a bias potential of +100 mV vs. SCE. Furthermore, the LB five-layer films could give rise to the IPCE value of 1.5% at +100 mV without significant decline of the quantum yields, which was due to the function of C60 as an electron carrier to improve the interlayer electron transfer through each layer. These results have demonstrated a promising method for preparing the donor,acceptor systems using cellulose as a scaffold in the LB films. [source] Properties of plant plasma membrane lipid models , bilayer permeability and monolayer behaviour of glucosylceramide and phosphatidic acid in phospholipid mixturesPHYSIOLOGIA PLANTARUM, Issue 2 2000Anna H. Berglund Phosphatidic acid (PA) and glucosylceramide (Cer), constituents of plant plasma membranes, were used in interaction studies with the major plasma membrane lipid components, phosphatidylcholine (PC) and phosphatidylethanolamine (PE). With molecular species combinations, representative for plant plasma membranes, packing conditions during compression of monolayers of PC/PE mixtures with different amounts of PA or Cer added, were investigated. In contrast to the behaviour of single PA or single Cer, which exhibited condensed compression curves, as compared with curves representative for phosphoglycerides, the triple mixtures of PC/PE with PA or Cer showed markedly expanded monolayer films. These data were evaluated as a spontaneous heterogeneous dispersion of PA and Cer in the PC/PE mixture. Membrane vesicles produced with different amounts of PA added to a PC/PE mixture of 1:1 (mol/mol) had an almost linear increase in permeability for glucose (chosen as a common polar low-molecular mass metabolite) with increasing percentage PA. The presence of PA in plasma membranes and its possible function are discussed in relation to recent reports on anionic protein-lipid interactions. PC/PE vesicles with different amounts of Cer added did not influence the permeability for glucose at 2.5 and 5 mol%, but did so, significantly, at 7.5 and 9 mol%. [source] Kinetic, Thermodynamic, and Mechanistic Patterns for Free (Unbound) Cytochrome c at Au/SAM Junctions: Impact of Electronic Coupling, Hydrostatic Pressure, and Stabilizing/Denaturing AdditivesCHEMISTRY - A EUROPEAN JOURNAL, Issue 27 2006Dimitri E. Khoshtariya Prof. Dr. Abstract Combined kinetic (electrochemical) and thermodynamic (calorimetric) investigations were performed for an unbound (intact native-like) cytochrome c (CytC) freely diffusing to and from gold electrodes modified by hydroxyl-terminated self-assembled monolayer films (SAMs), under a unique broad range of experimental conditions. Our approach included: 1) fine-tuning of the charge-transfer (CT) distance by using the extended set of Au-deposited hydroxyl-terminated alkanethiol SAMs [-S-(CH2)n -OH] of variable thickness (n=2, 3, 4, 6, 11); 2) application of a high-pressure (up to 150,MPa) kinetic strategy toward the representative Au/SAM/CytC assemblies (n=3, 4, 6); 3) complementary electrochemical and microcalorimetric studies on the impact of some stabilizing and denaturing additives. We report for the first time a mechanistic changeover detected for "free" CytC by three independent kinetic methods, manifested through 1) the abrupt change in the dependence of the shape of the electron exchange standard rate constant (ko) versus the SAM thickness (resulting in a variation of estimated actual CT range within ca. 15 to 25 Å including ca. 11 Å of an "effective" heme-to-,-hydroxyl distance). The corresponding values of the electronic coupling matrix element vary within the range from ca. 3 to 0.02 cm,1; 2) the change in activation volume from +6.7 (n=3), to ,0 (n=4), and ,5.5 (n=6) cm3,mol,1 (disclosing at n=3 a direct pressure effect on the protein's internal viscosity); 3) a "full" Kramers-type viscosity dependence for ko at n=2 and 3 (demonstrating control of an intraglobular friction through the external dynamic properties), and its gradual transformation to the viscosity independent (nonadiabatic) regime at n=6 and 11. Multilateral cross-testing of "free" CytC in a native-like, glucose-stabilized and urea-destabilized (molten-globule-like) states revealed novel intrinsic links between local/global structural and functional characteristics. Importantly, our results on the high-pressure and solution-viscosity effects, together with matching literature data, strongly support the concept of "dynamic slaving", which implies that fluctuations involving "small" solution components control the proteins' intrinsic dynamics and function in a highly cooperative manner as far as CT processes under adiabatic conditions are concerned. [source] | ||||||||||