Sorption selectivity definition

For applications in modem technology fields, not only high surface area and large pore volume, but also a sharp pore-size distribution at a definite size and control of strrface natirre of pore walls are strongly required. In order to control the pore stmcture in carbon materials, studies on the selection of prectrrsors and preparation conditions have been extensively carried out and certain successes have been achieved [ 1-3]. Pore sizes and their distributions in adsorbents have to comply with requirements from different applications. Thus, relatively small pores are needed for gas adsorption and relatively large pores for liquid adsorption, and a very narrow PSD is reqtrired for molecular sieving applications. Macropores in carbon materials were fotmd to be effective for sorption of viscous heavy oils. Recent novel techniques to control pore stmcture in carbon materials can be expected to contribute to overcome this limitation [41-46]. 

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