Nano porous structures

In its role as a catalyst, the surface condition of the as-leached nickel nanostructure is highly important. In particular, the sites occupied on the surface of the catalyst by any residual aluminium atoms are of interest. In order to investigate the surface configuration of as-leached surfaces a Metropolis Monte Carlo (MMC) model is subsequently applied. As a starting point the MMC model exploits the nano-porous structure already predicted by the kMC approach. The MMC model aims to simulate the appearance of Al-rich surface configurations that are routinely observed in experiment. 

Once the BKL algorithm is applied Al atoms are progressively removed (at a rate that decreases with time) (8). Simultaneously, adatom diffusion of Ni results leads to the development of a nano-porous structure. 

Figure 1 3D predicted nano-porous structure of leached NiAl3 precursor... 

A kinetic Monte Carlo model has been shown to be capable of simulating as-leached nano-porous structures that develop during leaching of NiAl alloys. 

Polyamino acids can be considered as models for conformational studies, providing an atomistic description of the secondary structural motifs typically found in proteins [30-39]. Two-dimensional hydrogen-bonded layers and columns in the structures of crystalline amino acids can mimic S-sheets and helices in proteins and amyloids [40 5], and can be compared with two-dimensional crystalline layers at interfaces [46-58]. Nano-porous structures of small peptides can mimic cavities in proteins [24, 59-63]. One can also prepare crystals in which selected functional groups and side chains are located with respect to each other in the same way, as at recognition sites of substrate-receptor complexes, and use the systems to simulate the mutual adaptation of components of the complex responsible for recognition. 

Catalytic properties of novel nickel(II) phosphate with nano-porous structure... 

For example, HEBM of graphite powder produces a disordered and nano-porous structure through agglomeration of nanosized particles under ball impacts nucleation. The contaminations from milling act as catalysts to promote nanotube formation during the subsequent annealing. 

Long and narrow 1-D nano-porous structures, however, result in large loss of the driving force for the reaction, as evident from Eq. (1). Accordingly, it is quite unlikely that the ionic species moves rapidly inside or out of the 1-D nano-porous stmcture with narrow and deep pores. This is unfavorable for sustained high-rate operation of the electrochemical devices. 

In addition to sensing applications, diamond electrodes have been examined for use in energy storage devices. A diamond electrode with nano-porous structures on its surface can exhibit a high double-layer capacitance in both aqueous [13] and... 

Nano-porous structures were prepared by oxygen plasma etching through anodic alumina masks with 400-nm diameter pores on polished diamond films [16][17]. The average diameter and average depth of the pores were 400 nm and 1.8 p,m, respectively. 

For this version, the micro structured AlMg3 platelets were coated with silver by CVD in [43], In [44], the platelets were either totally made of silver (as constmction material) or of AlMg3 and then coated by PVD with silver. In the latter version, two sub-versions were made with and without anodic oxidation to a generate nano-porous surface structure. 

In principle the bicontinuous 3-dimensional network structure of MCM-48 would act as a good catalytic support.[7] However, its lower hydrothermal and thermal stability has led to much less application of MCM-48 in catalysis. Recently, a family of mesoporous molecular sieves (denoted as MSU-G) with vesicle-like hierarchical structure, worm-like mesoporous structure and bicontinuous nano-porous silica had been synthesized.[8-10] It was proposed that highly accessible mesoporous materials could be obtained through different synthetic procedure and composition. 

Radhakrishnan and co-workers [6] also studied the freezing of CCI4 in activated carbon fibers (ACF) of uniform nano-scale structures, using Monte Carlo simulation and differential scanning calorimetry (DSC), klicro-porous activated carbon fibers serve as highly attractive adsorbents for simple non-polar molecules. The DSC experiments verified the predictions about the increase in T/. and the molecular results were consistent with equation (1) for pore widths in the mesoporous range they also explained the deviation from the linear behavior in the case of micropores. 

A model for the nano-structural evolution of Raney-type nickel catalysts (widely used in hydrogenation reactions) from the constituent intermetallic phases present in nickel-aluminium precursor alloys is presented here. Nano-porous nickel catalysts are prepared via a caustic leaching process where the NiAl alloy powder (typically 50-50 at.%) is immersed in concentrated NaOH solution in order to leach away the aluminium present to leave a highly-porous nickel catalyst (often referred to as spongy nickel). 

Firstly, a kinetic Monte Carlo (kMC) [8] for the nano-structural evolution of so-called spongy nickel from the constituent intermetallic phases present in nickel-aluminium precursor alloys is described. Experimental data concerning nano-porous nickel catalyst powder used in this paper are derived from leached NiAl alloy powder produced via a spray-atomization route rather than the conventional cast-and-crushed route. 

Figure 8.51 CMK-5 (a) TEM image viewed along the direction of the ordered nano porous carbon and the corresponding Fourier diffractogram. (b) Schematic model for the carbon structure, (c) XRD pattern indicating the hexagonal order between carbon cylinders. Reproduced with permission from [35]. Copyright (2001) Nature Publishing...

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