As nanoscale

In this final chapter, we will review the current frontier of the applications of CNTs. Nanoscale applications such as nanoscale devices and ultra-fine probe, as well as macroscale applications such as field emission, energy storage and... 

Electrochemistry is the basis of many important and modem applications and scientific developments such as nanoscale machining (fabrication of miniature devices with three dimensional control in the nanometer scale), electrochemistry at the atomic scale, scanning tunneling microscopy, transformation of energy in biological cells, selective electrodes for the determination of ions, and new kinds of electrochemical cells, batteries and fuel cells. 

Micelles have internal cavities of the order of 1-3 nm diameter, which allow them to act as nanoscale photochemical reactors for incarcerated guest molecules. Photons absorbed by the guest provide the necessary activation to break covalent bonds in the guest molecule, while the resulting reaction intermediates are themselves constrained to remain in the micelle cavity. 

Sitharaman B, Tran LA, Pham QP, Bolskar RD, Muthupillai R, Flamm SD, Mikos AG, Wilson LJ (2007) Gadofullerenes as nanoscale magnetic labels for cellular MRI. Contrast Media Mol. Imag. 2 139-146. 

B. Regan, S. Aloni, R. Ritchie, U. Dahmen, and A. Zettl, Carbon nanotubes as nanoscale mass... 

While the variety of NPs used in catalytic and sensor applications is extensive, this chapter will primarily focus on metallic and semiconductor NPs. The term functional nanoparticle will refer to a nanoparticle that interacts with a complementary molecule and facilitate an electrochemical process, integrating supramolecular and redox function. The chapter will first concentrate on the role of exo-active surfaces and core-based materials within sensor applications. Exo-active surfaces will be evaluated based upon their types of molecular receptors, ability to incorporate multiple chemical functionalities, selectivity toward distinct analytes, versatility as nanoscale receptors, and ability to modify electrodes via nanocomposite assemblies. Core-based materials will focus on electrochemical labeling and tagging methods for biosensor applications, as well as biological processes that generate an electrochemical response at their core. Finally, this chapter will shift its focus toward the catalytic nature of NPs, discussing electrochemical reactions and enhancement in electron transfer. 

To a first approximation, the redox species at the periphery of the NP tend to react independently of each other. For example, a gold MPC functionalized with phenothiazine ligands16 demonstrates that the number of electrochemically oxidizable phenothiazine groups is identical to the average number present as measured by NMR (Fig. 11.2). The independent, electrochemically NP reactive surfaces act as nanoscale receptors that provide a larger reactive surface area for both catalytic and sensing applications. 

Synthesis of solid state materials using surfactant molecules as template has been extensively used in this decade. Among the advantages of the use of amphiphilic molecules, the self-assembling property of the surfactants can provide an effective method for synthesising ceramic and composite materials with interesting characteristics, such as nanoscale control of morphology, and nano or mesopore structure with narrow and controllable size distribution [1-5]. 

The properties of ordered structures in block copolymer melts have yet to be fully exploited, but the structural and rheological anisotropy is likely to lead to applications not all of which can be envisaged yet. The precision self-assembly of block copolymers into ordered structures for thin film and interfacial applications has enormous potential. Other applications such as nanoscale templates, membranes and filters could exploit the self-assembly of block copolymers into domains with periods 10-100 nm. The possibilities are limited only by the molecular engineer s imagination. 

Guerrot, 2000 Pokrovski, Kara and Roux, 2002, 2361). Arsenian pyrite is also common in hydrothermal deposits at temperatures as low as 150 °C and as high as 250-300 °C (Kesler, Riciputi and Ye, 2005, 132 Reich et al., 2005, 2788 Pokrovski, Kara and Roux, 2002, 2375, 2361). Most pyrites contain only 0.02-0.5 wt % arsenic (Welch et al., 2000, 597). However, arsenian pyrites may host up to 6 wt % arsenic as a solid solution with sulfur (Reich and Becker, 2006). Although pyrites from Nevada, USA, contain as much as 19.76 wt%, much of this arsenic exists as nanoscale arsenopyrite or other mineral inclusions rather than as a true solid solution (Reich et al., 2005 Reich and Becker, 2006, 2784-2786). 

Crystalline nanorings, literally closed circular nanoparticles with a hollow centre, were first prepared from zinc oxide in 2004 by a spontaneous self-coiling process from polar nanobelts.44 Semiconductor nanorings and indeed interestingly shaped nanoobjects in general, promise much in the way of applications as tools to probe fundamental physical phenomena and as nanoscale sensors, transducers, and resonators. 

A more recent trend in polymer materials research is the hybridization of cellulosic polysaccharides with inorganic compounds natural and synthetic layered clays, silica, zeolites, metal oxides, and apatites are employable as nanoscale components. In addition, if mesoscopic assemblies such as liquid-crystalline ordering are used in the construction of new compositional systems, the variety of functionalized cellulosic materials will be further expanded. 

Mechanically interlocked molecules, such as bistable catenanes [13] and [2]rotax-anes [14], constitute some of the most appropriate candidates to serve as nanoscale switches and machines in the rapidly developing fields of nanoelectronics [15] and nanoelectromechanical systems (NEMS) [16]. The advantages of using mechanically interlocked molecules in the fields of molecular electronics and... 

SPM is widely used as research tool and industrial measuring instrument, and has drawn attraction as nanoscale processing tool at nanometer order from the initial stage of development. The atomic operation became possible by SPM [54], and scanning probe nanolithography (SPNL) was developed at ca. 10 nm level [55]. There are three major categories for SPNL as follows ... 

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