Nanofilms

Itoh et al. and Wang et al. have created an organic/inorganic hybrid nanofilm from the chemical vapor deposition of M0O3, followed by the ion-exchange-induced intercalation 

The use of self-assembled monolayer formation has been adapted to the deposition of conducting-polymer nanofilms by the chemical polymerization of aniline at an amino-silane surface that acts as the seed layer for polymerization, which led to a more ordered nanofibrous growth than would be seen using bulk chemical polymerization [39]. This was shown to be capable of detection of 0.5 ppm ammonia vapor, with a 

Nitrite is a common environmental pollutant. Electrochemically, it is a difficult species to reduce without the application of high overpotentials, and many have explored catalytic mechanisms to make it more amenable to reduction. Li and Lin [45] modified PPy nanowires with Pt nanoclusters and showed enhanced performance of the composite over an electrode modified by Pt nanoparticles alone, with increased reduction current 

7 Metal-Oxide Nanoparticles/Conducting-Polymer Nanocomposites 

Several other examples of conducting-polymer/metal oxide nanocomposite materials also exist for chemical sensing of a range of analytes, including humidity [58,59], NO2, [60,61], CO and H2 [60], and H2O2 [62]. This latter example employed the use of Prussian blue, which is an iron complex with excellent catalytic properties, particularly towards O2 and H2O2. Miao et al. [62] stabilized nanoparticles of Prussian blue with polymerization of a PANI shell to form a Prussian blue/PANI core-shell composite. 

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Zhenyu Zhang, Xinchun Lu, Jianbin Luo, Yang Liu, Chenhui Zhang, Preparation and Characterization of Fa203 Doped Diamond-Like Carbon Nanofilms (I) Structure Analysis," Diamond Relat. Mater., Vol. 16, No. 11, 2007, pp. 1905-1911. 

The ECALE synthesis of V-VI (V Sb, Bi) compounds has been attempted in a few works. Antimony telluride, Sb2Te3, nanofilms with a homogeneous microstructure and an average size of about 20 nm were formed epitaxially on a Pt substrate [61]. The optical band gap of these films was blue-shifted in comparison with that of the bulk single-crystal Sb2Tc3 compound. 

Kondo, Y, Ru, Q. and Takayanagi, K. (1999) Thickness Induced Structural Phase Transition of Gold Nanofilm. Physical Review Letters, 82, 751—754. 

Multilayer Halloysite Assembly lor Organized Nanofilms. Forming Low Density Tubule Nanoporous Materials... 

Stein EW, Grant PS, Zhu H, McShane MJ (2007) Microscale enzymatic optical biosensors using mass transport limiting nanofilms. 1. Fabrication and characterization using glucose as a model analyte. Anal Chem 79 1339-1348... 

The Nobel laureate Richard P. Feynman described, in a lecture delivered in 1959, the future of miniaturization. The published version of his lecture is called There s Plenty of Room at the Bottom and in it can be found a recipe for putting the entire Encyclopedia Britan-nica on the very small head of a very small pin. Feynman s comments set into motion an entirely new area of study and have lead to what have become known as the fields of nanoscience and nanotechnology. Chemists, physicists, materials scientists, and engineers have come together over the past several decades to produce with high accuracy and precision materials that have dimensions measured in nanometers (nm, 10 meters, about 1/100 000 the width of a human hair). Specifically, materials with one, two, or three dimensions of 100 nm or less (called, respectively, nanofilms, nanotubes, and nanoparticles) qualify as products of nanotechnology. It appears that almost any chemical substance that is a solid under ordinary conditions of temperature... 

Fig. 9 A topographic thickness map generated with a scanning eUipsometer (iElli2000, Nanofilm Technologie, GmbH) of a polystyrene brush with an average thickness of 140 0.6 nm over an area of 100 x 193 p.m. The area within the square is very smooth, with a standard deviation of 4 A. (Reproduced with permission from [52] Wiley)...

Nanofilms can be used simply as very thin coatings. For example, nanoscale coatings to protect and enhance modern plastic spectacle lenses have been developed, including selfassembling top coatings for nonreflective lenses to protect the antireflective... 

Indeed we study the two-dimensional systems in Section 5. In this section we will analyze the structural, electronic and, in particular, the optical properties of Si and Ge based nanofilms (Section 5.1), of Si superlattices and multiple quantum wells where CalQ and SiC>2 are the barrier mediums (Sections 5.2 and 5.3). The quantum confinement effect and the role of symmetry will be considered, changing the slab thickness and orientation, and also the role of interface O vacancies will be discussed. 

Figure 28 (a) The endbead density profiles of PFPE nanofilms as a function of w,... 

The advances in nanotechnology and synthesis methods have enabled nanomaterials to be produced in various shapes and structures. Coating of a luminescent layer activated by lanthanide ions on nanoparticles such as SiC>2 or AI2O3 is one of such approaches to develop new nanophosphors. In section 6, we review recent work on interesting spectroscopic features and luminescence dynamics of lanthanide ions in other novel low-dimensional nanostructures including core-shell, one-dimensional (ID) nanowires and nanotubes, two-dimensional (2D) nanofilms, hollow nanospheres, 2D nanosheet and nanodisk which have also attracted extensive attention. 

As discussed early in this chapter, quantum confinement has little effect on the localized electronic levels of lanthanide ions doped in insulating nanocrystals. But when the particle size becomes very small and approaches to a few nanometers, some exceptions may be observed. The change of lanthanide energy level structure in very small nanocrystals (1-10 nm) is due to a different local environment around the lanthanide ion that leads to a drastic change in bond length and coordination number. Lanthanide luminescence from the new sites generated in nanoparticles can be found experimentally. The most typical case is that observed in nanofilms ofEu Y203 with a thickness of 1 nm, which exhibits a completely different emission behavior from that of thick films (100-500 nm) (Bar et al., 2003). 

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