Electrodes self-assembly

Figure 2.11 Cyclic voltammograms of (PAH-Os)4(PVS)4PAH-Os multilayer modified Au electrode self-assembled from PVS and PAH-Os solutions of pH 8.3 and measured in pH 7.3 solutions of different KNO3 concentration 8, 40, 137, 481, 932 and 1500 mM. Sweep rate 0.025 mVs Taken from Ref [107].

Au(lOO) electrodes. Self-assembled thiol layers on Au(lOO) have also been studied. 

Immobilized at the monolayer level at a Au electrode self-assembled with 2-aminoethanethiol... 

S. Hoeppener, R. Maoz, S. R. Cohen, L. F. Chi, H. Fuchs, and J. Sagiv, Metal nanoparticles, nanowires, and contact electrodes self-assembled on patterned monolayer templates—a bottom-up chemical approach, Adv. Mater., 14,1036 (2002). 

Initially, molecular combing was used to comb a nanotube over a pair of gold electrodes. Self-assembled monolayers (SAMs) on the electrodes and the silicon substrate were used to help induce the SWCNT (dispersed via sodium dodecyl sulphate [SDS]) to deposit at the correct location the liquid-air meniscus was then used to orient the nanotube across the two electrodes (Fig. 16.2b). This method has the advantage of being easily scalable. However, contact with the nanotube is superior when the electrode is deposited with e-beam lithography over the nanotube. Because molecular combing is a very convenient way to extend nanotubes on the substrate, it is often used in this case as well. These studies have demonstrated... 

Figure C3.2.4. Plot of the log of photocurrent against number of methyl units in a alkylsilane based monolayer self-assembled on a n silicon electrode. The electrode is immersed in a solution witli an electron donor. Best fits of experimental data collected at different light intensities ( ) 0.3 mW cm ( ) 0.05 mW cm. From [10].

Therefore, the following method was suggested and realized (the scheme is shown in Fig. 17). A 1.5 M solution of KCl or NaCl (the effect of preventing BR solubility of these salts is practically the same) was used as a subphase. A platinum electrode was placed in the subphase. A flat metal electrode, with an area of about 70% of the open barriered area, was placed about 1.5-2 mm above the subphase surface. A positive potential of +50 -60 V was applied to this electrode with respect to the platinum one. Then BR solution was injected with a syringe into the water subphase in dark conditions. The system was left in the same conditions for electric field-induced self-assembly of the membrane fragments for 1 hour. After this, the monolayer was compressed to 25 mN/m surface pressure and transferred onto the substrate (porous membrane). The residual salt was washed with water. The water was removed with a nitrogen jet. 

A major challenge and important application is nano-wiring of electronic circuits mediated by self-assembled DNA or protein structures providing condncting connection between miniaturized electrodes [51,52]. The use of self-assembled DNA for wiring two... 

Toyoda T, Kobayashi J, Shen Q (2008) Correlation between crystal growth and photosensitization of nanostructured HO2 electrodes using supporting H substrates by self-assembled CdSe quantum dots. Thin SoUd Films 516 2426-2431... 

On detailed electrical characteristics of a SET transistor utilizing charging effects on metal nanoclusters were reported by Sato et al. [26]. A self-assembled chain of colloidal gold nanoparticles was connected to metal electrodes, which were formed by electron-beam lithography. The cross-linking of the particles as well as their connection to the electrodes results from a linkage by bifunctional organic molecules, which present the tunnel barriers. 

Figure 9. SET transistor, based on self-assembling of gold nanoclusters on electrodes fabricated by electron-beam epitaxy. (Reprinted with permission from Ref [26], 1997, American Institute of Physics.)...

A similar route has been followed most recently by Weiss et al. who have fabricated a multi-island SE device from self-assembled ID gold nanocrystal chains [28]. They assembled thiol-stabilized 50 nm Au particles in a chainlike structure and used subsequently electron-beam lithography for electrode fabrication. Here it has to be... 

Gold electrodes coated by nanostructured self-assembled monolayer of TMPP and Cl2 are used as template for in situ synthesis of metallic nanoparticles (Figure 2). 

Most studies of ORR catalysis by metalloporphyrins have been carried out using water-insoluble catalysts absorbed on a graphite electrode in contact with aqueous solution. In a limited number of cases, four other approaches have been used catalysts imbedded in an inert film (i.e., Nafion or lipid) on the electrode surface self-assembled monolayers of catalysts catalysts in aqueous or mixed organic/aqueous solutions in contact with an electrode and catalysis in mixed aqueous/organic medium using... 

Relatively little work has been done on ORR catalysis by self-assembled mono-layers (SAMs) of metalloporphyrins. The advantages of this approach include a much better defined morphology, structure, and composition of the catalytic film, and the surface coverage, and the capacity to control the rate at which the electrons ate transferred from the electrode to the catalysts [CoUman et al., 2007b Hutchison et al., 1993]. These attributes are important for deriving the catal5d ic mechatfism. The use of optically transparent electrodes aUows characterization of the chemical... 

As this volume attests, a wide range of chemistry occurs at interfacial boundaries. Examples range from biological and medicinal interfacial problems, such as the chemistry of anesthesia, to solar energy conversion and electrode processes in batteries, to industrial-scale separations of metal ores across interfaces, to investigations into self-assembled monolayers and Langmuir-Blodgett films for nanoelectronics and nonlinear optical materials. These problems are based not only on structure and composition of the interface but also on kinetic processes that occur at interfaces. As such, there is considerable motivation to explore chemical dynamics at interfaces. 

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