Porous templates

Figure 1.15 TEM image of Pt nanoparticles that have been produced by lyotropic liquid crystal templating. Porous structures can be seen and are spaced in an hexagonal array. (Reprinted with permission from Ref [54], 1997 Wiley-VCH Verlag GmbH, Co. KCaA.)...

Statistical thermodynamic theories such as atomistic density functional theory (DFT) for the computation of adsorption isotherms in simple pore geometries such as slits [15] or cylindrical capillaries [16] This category also includes integral equation methods for porous matrices [17] and templated porous materials [18],... 

A adsorption model for a templated porous material may be posed in terms of seven replica Ornstein-Zernicke (ROZ) integral equations [58-60] that relate the direct and total correlation functions, c, (r) and hij (r), respectively, of the matrix-adsorbate system... 

Riccardo and coworkers [50, 51] reported the results of a statistical thermodynamic approach to study linear adsorbates on heterogeneous surfaces based on Eqns (3.33)—(3.35). In the first paper, they dealt with low dimensional systems (e.g., carbon nanotubes, pores of molecular dimensions, comers in steps found on flat surfaces). In the second paper, they presented an improved solution for multilayer adsorption they compared their results with the standard BET formalism and found that monolayer capacities could be up to 1.5 times larger than the one from the BET model. They argued that their model is simple and easy to apply in practice and leads to new values of surface area and adsorption heats. These advantages are a consequence of correctly assessing the configurational entropy of the adsorbed phase. Rzysko et al. [52] presented a theoretical description of adsorption in a templated porous material. Their method of solution uses expansions of size-dependent correlation functions into Fourier series. They tested... 

Rzysko, W., Sokolowski, S., and Pizio, O. (2002). Theory of adsorption in a polydisperse templated porous material hard sphere systems. J. Chem. Phys., 116, 4286-92. 

Fig. 6.3-3 (a) TEM image of lie-templated porous silica prepared in a sol-gel reaction ofl goflijwithl gof silica at a temperature of 40 °C. The scale bar is 50 nm. Inset 2d Fourier transform of the picture. 

EISA. The mechanism in each case has been the subject of much research and the current understanding of each mechanism is described below. The other two methods to produce mesoporous templated materials are electrodeposition,which has been successfully used to produce surfactant templated porous metal films from high concentration surfactant solutions, and nanocasting, where a surfactant templated silicate is used as a sacrificial template to generate further porous materials by coating the silica structure in another oxide or carbon precursors. The second material is sintered or solidified, and the silicate removed by HE or high pH solvent wash. This is discussed further in Section 2.10. 

Templated Porous Carbon Materials Recent Developments... 

Several reviews covering the synthesis, properties and applications of porous carbons, especially mesoporous carbon materials, can be found in the literature. In this chapter, we summarise the recent developments in the synthesis and characterisation of templated porous carbon materials. Particular attention is paid to the synthesis of structurally ordered porous carbon materials with narrow pore size distribution via both hard and soft template methods. We especially emphasise those so-called breakthroughs in the preparation of porous carbon materials. The chapter is divided into three sections according to the pore size of carbon materials we first consider the synthesis of microporous carbon materials using zeolites and clays as hard template, then summarise the preparation of mesoporous carbon materials via both hard template and self-assembly... 

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