Macroporous media

Applications of relaxation times to the characterization of other macroporous media... 

For the estimation of the diffusion coefficient in isotropic macroporous media, the relation... 

Van Brakel, J. and Heertjes, P.M., Analysis of diffusion in macroporous media in terms of a porosity, a tortuosity and a constrictivity factor, Int. J. Heat Mass Transfer, 17 1093-1103, 1974. 

Apart from diffusion in continuum phase, the transport of surface-adsorbed molecules and capillary condensate takes place in meso- and macroporous media. In order to model transport of adsorbable vapor at elevated pressure, it is necessary to consider the type of adsorption occurring monolayer adsorption, multilayer adsorption, or capUlary condensation [38]. Models for surface diffusion have been proposed... 

Kanamori, K. Nakanishi, K. Hanada, T., Spinodal Decomposition in SUoxane Sol-Gel Systems in Macroporous Media. Soft Matter 2009,5,3106-3113. 

Because the diflusion rate for small molecules is quite high and the equilibrium concentration within the pores is reached quickly, their concentration in the pores is almost identical to that in the pulse. The situation is quite different in the case of macromolecules. The slow diflusional mass transfer of macromolecules in macroporous media result in severe peak broadening. The efficiency of the whole separation system deteriorates rapidly as the flow rate increases. As a result, longer columns or slower flow rates must be used to achieve the desired separation [8]. 

Simple techniques such as emulsion and dispersion polymerization which provide monodisperse beads are not suitable for the preparation of macroporous media. Alternative approaches based on the dropwise introduction of a polymerization mixture containing a thermally or photochemically triggered initiator into a heated iiiunisible liquid in which the polymerization proceeds under conditions that avoid coalescence have met with some success. The droplets... 

The theory of surface adsorption and adsorption in macroporous media is discussed in Section TV. After a brief overview of the possible thermodynamic approaches, we develop one of them in detail, the potential theory of multicomponent adsorption. This method of treatment makes it possible to discuss comprehensively at least one possible thermodynamic theory of multicomponent adsorption and avoid eclectic jumping between multiple theories and approaches proposed in this area. 

Other limitations of the theory follow Irom the way it is formulated. For example, the theory must be corrected for adsorption in mesoporous and macroporous media by taking into account the phenomenon of capillary condensation, as described earlier. 

Godefroy, S., J. P. Korb, M. Heury and R. G. Bryant (2001). Surface Nuclear Magnetic Relaxation and Dynamics of Water and Oil in Macroporous Media . Physical Review E 64 021605. 

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