Nanopores

As an indication of the types of infonnation gleaned from all-electron methods, we focus on one recent approach, the FLAPW method. It has been used to detennine the band stmcture and optical properties over a wide energy range for a variety of crystal stmctures and chemical compositions ranging from elementary metals [ ] to complex oxides [M], layered dichalcogenides [, and nanoporous semiconductors The k p fonnulation has also enabled calculation of the complex band stmcture of the A1 (100) surface... 

Starrost F, Krasovskll E E, Schattke W, Jockel J, Simon U, Adelung R and Kipp L 2000 Cetineltes electronic, optical, and conduction properties of nanoporous chalcogenoantimonates Phys. Rev. B 61 15 697... 

Gies FI, Marler B and Werthmann U 1998 Synthesis of porosils crystalline nanoporous silicas with cage- and channel-like void structures Moiecuiar Sieves Science and Technoiogy vo 1, ed FI G Karge and J Weitkamp (Berlin Springer) pp 35-64... 

M. Schoen, D. J. Diestler. Ultrathin fluid films confined to a chemically heterogeneous sht-shaped nanopore. Phys Rev E 5(5 4427—4440, 1997. 

In conclusion, a large fraction of singlelayer sheets and nanopores is beneficial for... 

Xing and Dahn recently reported [70] that <2 R for disordered carbon and MCMB 2800 can be markedly reduced from about 180 and 30mAhg l to less than 50 and lOmAhg-1 respectively, when the carbon anode and cell assembly are made in an inert atmosphere and never come in contact with air. This indicates that these carbons contain nanopores that... 

U. (1998) Synthesis of porosils Crystalline nanoporous silicas with cage-and channel-like void structures in Molecular Sieves Science and Technology, vol. 1 (eds H.G.Karge and ). Weitkamp), Springer, Heidelberg, pp. 35-64. 

A number of different approaches have been taken to describing transport in porous media. The objective here is not to review all approaches, but to present a framework for comparison of various approaches in order to highlight those of particular interest for analysis of diffusion and electrophoresis in gels and other nanoporous materials. General reviews on the fundamental aspects of experiments and theory of diffusion in porous media are given... 

Chan, VZH Hoffman, J Lee, VY latrou, H Avgeropoulos, A Hadjichristidis, N Miller, RD Thomas, EL, Ordered Bicontinuous Nanoporous and Nanorelief Ceramic Pihns from Self-Assembling Polymer Precursors, Science 286, 1716, 1999. 

FIG. 3 Setup of simulation cell of confined electrolyte with periodic boundary conditions, (a) Electrolyte bound by two infinitely long charged plates, representing a slit pore, (b) Electrolyte in a cylindrical nanopore. 

A question of practical interest is the amount of electrolyte adsorbed into nanostructures and how this depends on various surface and solution parameters. The equilibrium concentration of ions inside porous structures will affect the applications, such as ion exchange resins and membranes, containment of nuclear wastes [67], and battery materials [68]. Experimental studies of electrosorption studies on a single planar electrode were reported [69]. Studies on porous structures are difficult, since most structures are ill defined with a wide distribution of pore sizes and surface charges. Only rough estimates of the average number of fixed charges and pore sizes were reported [70-73]. Molecular simulations of nonelectrolyte adsorption into nanopores were widely reported [58]. The confinement effect can lead to abnormalities of lowered critical points and compressed two-phase envelope [74]. 

RPM model, but theories for the SPM model electrolyte inside a nanopore have not been reported. It is noticed that everywhere in the pore, the concentration of counterion is higher than the bulk concentration, also predicted by the PB solution. However, neutrality is assumed in the PB solution but is violated in the single-ion GCMC simulation, since the simulation result of the counterion in the RPM model is everywhere below the PB result. There is exclusion of coion, for its concentration is below the bulk value throughout the pore. Only the solvent profile in the SPM model has the bulk value in the center of the pore. 

FIG. 11 Schematic illustration of the electric potential profiles inside and outside a nanopore with lipid bilayer membranes separating the internal and external electrolyte solutions. The dotted line is a junction potential representation where the internal potential is shifted. 

FIG. 17 Diffusion coefficients of the counterions and coions of a 1 1 RPM model electrolyte in a cylindrical nanopore of i = lOd. The circles and triangles represent the results of coions and counterions, respectively. 

Proceedings of the 5 " International Symposium on the Characterisation of Porous Solids (COPS-Vj, Heidelberg, Germany, May 30- June 2, 1999 edited by K.K.Unger,G.Kreysa and J.P. Ba lt Volume 129 Nanoporous Materials II... 

Edited by A. Gamba, C. Colella and S. Coluccia Volume 141 Nanoporous Materials III... 

In addition, iron(II) complexes of tetraaza macrocyclic ligands 17-20 were encapsulated within the nanopores of zeolite-Y and were used as catalysts for the oxidation of styrene with molecular oxygen under mild conditions (Scheme 9) [57]. 

Ivanou DK, Streltsov EA, Fedotov AK, Mazamk AV, Fink D, Petrov A (2005) Electrochemical deposition of PbSe and CdTe nanoparticles onto p-Si(lOO) wafers and into nanopores in SiO2/Si(100) structure. Thin Solid Efims 490 154-160... 

Xi D, Pei Q (2007) In situ preparation of free-standing nanoporous alumina template for polybithiophene nanotube arrays with a concourse base. Nanotechnology 18 095602... 

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