Nano-size effects

The rapid development of nanotechnology has revolutionized scientific developments in recent decades [1]. The synthesis, characterization, and application of functionalized nanoparticles are currently a very active field of research [2], Due to the size limitation of metal nanoparticles, they show very unique properties, which are called nano-size effect or quantum-size effect , which is different from those of both bulk metals and metal atoms. Such specific properties are usually dominated by the atoms located on the surface. In nanoparticles systems, the number of atoms located on the surface of the particles increases tremendously with decreasing of the particle diameter [3]. 

This chapter focuses on the nano-structured effects on electrode durabUity, i.e. ceU durability. Fundamental aging mechanisms of the electrode components are also summarized. Long-time performances of the nano-structured electrodes are introduced to reveal the nano-size effects on electrode durabUity. Furthermore, models ever reported for the prediction of durabUity are included for better understanding the influence from the nano-size scale. 

Nano-size effects on isothermal grain growth... 

On the other hand, a thinner lubricant layer range finm sub-nanometre to sub-micrometer will be needed if the machine coirqronents become even smaller, and micro machining more common. In thirmer soft metaUic lubricant l ers, it is anticipated that the material properties of ultra-thin films differ from those of bulk properties, i.e., the nano size effect might affect the ffictional performance. For example, the coefficient of fiiction, durability of the film and influence of the atmosphere might be different from those of a thicker lubricant layer. However, studies concerning such thin solid lubricant layers are very few. 

We expect particularly interesting phenomena in the nanosize range, when the distance between the two interfaces (e.g. grain boundaries in nanocrystalline material) is of the order of magnitude of the Debye length or smaller. If we ignore structmal effects just mentioned (see however Fig. 5.108, page 261) we expect the thermodynamic profiles shown in Fig. 5.82. Nano-size effects will be considered explicitly in Example c. 

Keywords. Nano-sized space. Porphyrin, Cyclic oligomer. Multi-detectable molecule. Inverse-template effect... 

In recent years, there has been a growing interest in the synthesis and application of nano-scale zeolites. Zeolites with a crystal size smaller than 100 nm are the potential replacement for existing zeolite catalysts and can be used in novel environmentally benign catalytic processes. It is well known that the crystal size of zeolites has a great effect on their catalytic properties. The improved catalytic activity and selectivity as well as lower coke formation and better durability can be obtained over nano-sized zeolite crystals [2]. 

A continuous cross-flow filtration process has been utilized to investigate the effectiveness in the separation of nano sized (3-5 nm) iron-based catalyst particles from simulated Fischer-Tropsch (FT) catalyst/wax slurry in a pilot-scale slurry bubble column reactor (SBCR). A prototype stainless steel cross-flow filtration module (nominal pore opening of 0.1 pm) was used. A series of cross-flow filtration experiments were initiated to study the effect of mono-olefins and aliphatic alcohol on the filtration flux and membrane performance. 1-hexadecene and 1-dodecanol were doped into activated iron catalyst slurry (with Polywax 500 and 655 as simulated FT wax) to evaluate the effect of their presence on filtration performance. The 1-hexadecene concentrations were varied from 5 to 25 wt% and 1-dodecanol concentrations were varied from 6 to 17 wt% to simulate a range of FT reactor slurries reported in literature. The addition of 1-dodecanol was found to decrease the permeation rate, while the addition of 1-hexadecene was found to have an insignificant or no effect on the permeation rate. 

In this section, we will analyze the effects of a nano-sized HRI overlay on the distribution of the cladding modes (transversal fields, effective indices, coupling coefficients) to changes of its thickness and refractive index and to changes of the SRI. 

As can be inferred by the results obtained, the effect of nano-sized HRI coatings on LPGs is a drastic modification of their sensitivity characteristics, which ranges... 

We have seen that, in photosynthetic bacteria, visible light is harvested by the antenna complexes, from which the collected energy is funnelled into the special pair in the reaction centre. A series of electron-transfer steps occurs, producing a charge-separated state across the photosynthetic membrane with a quantum efficiency approaching 100%. The nano-sized structure of this solar energy-conversion system has led researchers over the past two decades to try to imitate the effects that occur in nature. 

Notably, the use of heteronuclear surface carbonyl species can lead to the preparation of well-defined supported bimetallic entities that can be used as model catalysts to study the promoter effect of a second metal. The close intimacy achieved between the two metals in the surface carbonyl species is related to the structural characteristics and catalytic properties of the final catalyst In the preparation of supported, tailored, multi-component catalysts, the use of metal carbonyl surface species still deserves to be studied to further explore the exciting field of nano-sized entities in catalysis. 

Recently, the synthesis of nano-sized HA has been proposed via reverse-micro-emulsion preparation, which is reported to be effective for controlling the hydrolysis and polycondensation of the alkoxides of the constituents. Using this preparation route, the nanoparticles crystallize directly to the desired phase at the relatively low temperature of 1050 °C and maintain surface areas higher than 100 m g after calcination at 1300 °C for 2h [107-109]. 

Wang Y, Herron N (1991) Nano-meter sized semiconductor clusters, materials synthesis and quantum size effects, and photophysical properties. J Phys Chem 95 525-532... 

Nano-structured Surfaces and Quantum Size Effects... 

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