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Blodgett Films (blodgett + film)
Selected AbstractsTetrathiafulvalene-, 1,5-Dioxynaphthalene-, and Cyclobis(paraquat- p -phenylene)-based [2]Rotaxanes with Cyclohexyl and Alkyl Chains as Spacers: Synthesis, Langmuir,Blodgett Films, and Electrical Bistability,ADVANCED FUNCTIONAL MATERIALS, Issue 5 2007X. Guo Abstract The synthesis and characterization of two new (TTF-DNP-CBPQT4+) [2]rotaxanes 1 and 2 is reported, based on tetrathiafulvalene (TTF), 1,5-dioxynaphthalene (DNP), and cyclobis(paraquat- p -phenylene) (CBPQT4+) with cyclohexyl and alkyl chains as the spacers. Multilayer Langmuir,Blodgett (LB) films of [2]rotaxanes 1 and 2 are prepared. Conducting atomic force microscopy, scanning tunneling microscopy, and two-terminal junction device studies indicate that the LB films of [2]rotaxanes 1 and 2 show electrical bistability behavior. By comparing with the TTF-DNP-CBPQT4+ [2]rotaxanes reported by Stoddart et,al. previously, the present results imply that proper modification of the chemical structures of the TTF unit and the spacer have negligible effect on the electrical bistability behavior of these TTF-DNP-CBPQT4+ [2]rotaxanes. These findings will allow for the design and preparation of new multifunctional TTF-DNP-CBPQT4+ [2]rotaxanes in the future. [source] Orientation Ordering of Nanoparticle Ag/Co Cores Controlled by Electric and Magnetic FieldsCHEMPHYSCHEM, Issue 7 2008Katarína Gmucová Dr. Abstract The effect of electric and magnetic fields on the sandwich structure Pt/hydrogenated amorphous silicon (a-Si:H)/stearic acid monolayer/Langmuir,Blodgett film of Ag/Co nanoparticles encapsulated in an organic envelope is studied. This structure is used as a working electrode in an electrochemical cell filled with NaCl solution (1 mM) and equipped with an Ag/AgCl reference electrode. Reversible changes in voltammograms are observed due to treatments (negative or positive bias voltage and simultaneous laser irradiation) applied to the designed structure before measurements. As an explanation of the observed phenomena we suggest that both the Co-up and Ag-up (on the a-Si:H surface) orientation orderings of nanoparticle Ag/Co cores are repeatedly reached. The role of the photovoltaic material (a-Si:H) in the observed behavior is explained. Voltammetric measurements with an applied magnetic field support our idea about the orientation ordering of nanoparticle cores. [source] Study of Nonlinear Optical Properties of Multilayer Langmuir,Blodgett Films Containing Bacteriorhodopsin,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2000Yu. O. Barmenkov ABSTRACT Multilayer oriented Langmuir,Blodgett films of bacteriorhodopsin were prepared and their nonlinear optical properties, including second harmonic generation and photoresponse at a two phase-modulated beams mixing, were investigated. The nonlinear component of refractive index of the films was measured. [source] Photoreactions and lateral patterning in Langmuir and Langmuir,Blodgett filmsTHE CHEMICAL RECORD, Issue 2 2007Mutsuyoshi Matsumoto Abstract Reversible morphological changes occur with photoisomerization of azobenzene in Langmuir,Blodgett (LB) films complexed with polycations, which contradicts an implicit assumption of the concept of free volume that two-dimensional film structures are preserved during the photoisomerization. J-aggregates of chromophores are formed by two processes. The first process is "light-induced J-aggregation" in which photoisomerized molecules form J-aggregates. The other process is "triggered J-aggregation," in which photoisomerization of one of the components triggers J-aggregation of another chemical species in the mixed films. Both processes of J-aggregation are in many cases accompanied by large morphological changes of the films. However, LB films fabricated using processes under isobaric conditions do not change their morphology during light-induced J-aggregation and are patterned with J-aggregates using ultraviolet illumination through a photomask. Phase separation in mixed LB films gives rise to two-dimensional patterns, which are used to fabricate templates by using an amphiphilic silane-coupling agent as one of the components in the mixed LB films. Nanopatterns are also fabricated. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 69,77; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20099 [source] | ||||||||||