Ultrathin single-layer

Fig. 1 Varied physical colors from ultrathin single layers of stain-etehed mesoporous silicon (LHS- A. Loni unpublished 2009) and anodized mesoporous sihcon photonic crystals (RHS - Gooding Group Univ. New South Wales, Austraha http //www.rsc.org/Publishing/ChemTech/Volume/ 2009/02/biosensors.asp)...

Figure 5.5 shows the variation of the pore size distribution as a function of cycles of surface-modification-based N2 adsorption isotherms. The pore size decreases with the modification cycle number. The reduction of the mesopore size for each cycle should be about twice the single-layer thickness. Accordingly, the effective singlelayer thickness is about 6 to 7 A based on the above BET measurements. This value is close to those estimated from the frequency changes of a quartz crystal balance for ultrathin fihns prepared by the surface sol-gel process on 2-D substrates." " ... 

Growing ultrathin metallic layers on a (chemically different) single crystal metal surface allows us to explore the changes in morphology and electronic structure that occurs as strain relief processes develop and relate them to the changes in reactivity, a subject of immense importance in catalysis. 

Liu, W. and M. Asheghi, Phonon-Boundary Scattering in Ultrathin Single-Crystal Silicon Layers. Applied Physics Letters, 2004. 84(19) p. 3819-3821. 

Fig. 5.14 TEM and thermal stability of Pt/Si0i TL02 nanocatalysts, (a, b) Pt/SiOiOTiOjNPs, (c, d) Pt/Si02 TL02NPs after calcination at 600 °C in air. (e, f) ADF STEM images and corresponding EDS line spectra of a single Pt/Si02 Ti02NPs to prove the existence of the ultrathin Ti02 layer. The bars represent (a, c, e) 10 nm and (b, d) 5 nm. Adapted from ref. [64]...

While the Kelvin probe is widely used in surface physics to study adsorption of molecules or reconstruction processes of single crystal surfaces (see e.g. [4]), which both cause a change in the surface or dipole potential, its application in electrochemistry is quite recent. As it is the only reliable reference electrode that can be applied to electrodes covered by ultrathin electrolyte layers, a common situation in atmospheric corrosion, it was first applied for electrochemical studies in corrosion science. Stratmann et al. [5-14] were the first who used a Kelvin probe as reference electrode. 

Nanohybrids can be prepared in the form of intercalated layered nanocomposites produced by co-assembly of guest biomolecules in the presence of exfoliated organoclay sheets (Section 8.4), or by wrapping single biomolecules in ultrathin layers of condensed organoclay oligomers (Section 8.5). Such approaches should provide new general routes towards the development of functional biomaterials with numerous applications. 

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