Copper monolayer coating

In order to make a conclusion about the reasons of the absorption band enhancing we also studied the surface relief for nanostructures prepared. Figs. 2a and 2b demonstrate the surface images of the copper monolayer and the two-layer Cu-Ag structure. In both cases metal coatings are nanostructured. It is worthwhile to note that at comparable lateral mean sizes of nanoparticles (10-15 nm), nanoparticle vertical sizes in Fig. 2a are different. 

Figure 4. Electron micrograph of a 2D gold colloid monolayer prepared on carbon-coated copper grids (coating thickness 100 A) by electrophoresis of a 0.5 mM citrate stabilized Au sol at an applied positive voltage of 50 mV. Reprinted with permission from ref 27. Copyright 1993 American Chemical Society.

When particular functions such as thiol, alcohol, carboxylic acid, nitrile or silyl derivatives, are present at one end of the bolas, they can easily stack on solid surfaces like gold, silver, copper or silica and form planar molecular monolayer (coated particles) (Fig. 7.33). The hydrophobic core may serve as a barrier or a solvent and the available headgroup allows molecular recognition in solution. 

Herzog G, Arrigan DWM (2003) Comparison of 2-mercaptoethane sulfonate and mercaptoacetic acid disorganized monolayer-coated electrodes for the detection of copper via underpotential deposition-stripping voltammetry. Electroanalysis 15 1302-1306... 

Colavita PE, Doescher MS, Molliet A, Evans U, Reddic J, Zhou J, Chen D, Miney PG, Myrick ML (2002) Effects of metal coating on self-assembled monolayers on gold. 1. Copper on dodecanethiol and octadecanethiol. Langmuir 18(22) 8503-8509... 

Fig. 114. Transmission electron micrograph (TEM) at limiting aperture coverage of PbS crystals formed by the slow (30 min) infusion of H2S to an AA monolayer in the Lauda film balance (kept at it = 26 mNm 1 surface pressure) floating on an aqueous 5.0xl0 4M Pb(N03)2 solution. The PbS particulate film was deposited on a formvar-coated, 200-mesh copper grid [647]...

Fig. 117. TEM of a PbSe particulate film. The film was formed by the 25 min infusion of H2Se (50 pi) over an AA monolayer, kept at 40 mN/m, which was floating on an aqueous 5.0 x 10-4 M Pb(N03)2 solution in the Lauda trough. The PbSe particulate film was transferred to an amorphous-carbon-coated 200-mesh copper grid. The bar = 200 nm [648]...

As an example, both monofunctional and multifunctional polymeric mercapto-esters were deposited onto optically smooth silicon wafers coated with vapor-deposited copper. The copper had been oxidized to Cu20, as verified by XPS. Infrared reflectance (RAIRS) at 81° (4 cm-1 resolution, 2000 scans) using an MCT detector yielded information on both the nature and the durability of the mercaptoester bond to the metal oxide film. A 16 cm l shift (1740— 1724 cm-1) was observed in the carbonyl absorption of stearyl thioglycolate (STG) deposited onto the Cu20 mirror. The absorption spectrum of the carbonyl region is illustrated in Fig. 11, both for the pure STG and the reacted monolayer. 

Data for copper coated with a stearic acid monolayer are included in the Table, in illustration of another type of hydrocarbon surface—one now rich in CH3 groups. As might be expected, the adsorption and contact angle behavior resembles more that for PE than for PTFE. 

The AuNPs were the same as those used for the fabrication of 3-D crystals [6]. In this case, fcc-structured monolayers and multilayers were formed, from solution, on carbon-coated copper grids (detailed structural investigations are provided in the original reference). 

Raman scattering gives information about molecular or sohd-state vibrations. In the presence of some electrode materials (e.g. silver or copper) a considerably enhanced sensitivity for molecules adsorbed at the electrode surface in the form of a monolayer can be achieved. This surface-enhanced Raman scattering effect can be transferred to other electrode materials coated in the form of a very thin layer onto a silver or copper substrate [32]. The recently developed TERS technique (Tip-Enhanced Raman Spectroscopy [33]) provides additional and highly resolved mapping information. 

Fig. 12 Left TEM image of a PbS particulate film. The scale bar represents 200 nm. The film was obtained by the infusion of H2S into an arachidic acid (AA) monolayer, floating on an aqueous 5.0 x 10" M Pb(N03)2 solution in a circular trough, for 45 min. The PbS film was deposited on an amorphous-carbon-coated copper grid. Right Schematic diagram showing the match of the proposed overlap between Pb + ions and AA headgroups o is AA headgroup and is Pb " ions. The dotted line area is a imit cell. (Reproduced from [195], 1995, Wiley)...

COPPER-COATED SELF-ASSEMBLED MONOLAYERS ALKANETfflOLS AND PROSPECTIVE MOLECULAR WIRES... 

The main objectives of our experiments were to determine if the monolayer was still present after the evaporation process to determine if the SAM had undergone any modifications to establish if these changes are reversible to determine whether increased electrical defects in the SAM result from evaporation and to determine the nature of the perturbations induced by the copper coating. The SAMs were characterized both as deposited, and after the removal of the copper overlayer with nitric acid, using FT-RAIRS and electrochemistry. Control experiments were performed to confirm that the nitric acid solutions used for the stripping had no effect on either the organization or the coverage of the SAM. 

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