No description available.

Here, we propose experiments that emulate processes that occur in disordered mesoporous media, on a macroscopic scale, by using a special designed high-vacuum system and 3D-printed channels to investigate features of complex porous media, such as fractal pores [3]. This set-up allows us to validate Knudsen diffusion theory in complex geometries more directly than has ever been the case. Some preliminary results will be shared, including features of the vacuum set-up, and Knudsen diffusion results in channels of varying geometry, including channels with a 3D-printed fractal surface.

The transport of liquid and solutes in porous media over widely different time and length scales, ranging from specific interactions with the surface (and the associated interfacial dynamics) to the effective pore diffusion through hierarchical porosity, is central to many environmental and technological processes. This interplay between surface functionality and hierarchical porosity requires, on the one hand, a detailed molecular-level picture of sorption, reaction, and mobility, and realistic geometrical models of hierarchically porous media on the other, to establish (and apply) quantitative morphology– functionality–transport relationships for the tailored preparation of ever more selective and efficient materials for storage, separation, and catalysis.

No description available.

Most theoretical treatments of Nuclear Magnetic Resonance (NMR) measurements of porous media assume ideal pore geometries for the pores (i.e. slabs, spheres or cylinders) with welldefined surface-to-volume ratios (S/V). This same assumption is commonly adopted for naturally occurring materials, where the pore geometry can differ substantially from these ideal shapes. In this paper the effect of the roughness of the pore surface on the T2 relaxation spectrum is studied. By homogenization of the problem using an electrostatic approach it is found that the effective surface relaxivity can increase dramatically in the presence of rough surfaces. This leads to a situation where the system responds as a pore with a smooth surface, but with significantly increased surface relaxivity. As a result the standard approach of assuming an idealized geometry with known surface to-volume and inverting the T2 relaxation spectrum to a pore size distribution is no longer valid. The effective relaxivity is found to be fairly insensitive to the shape of the roughness but strongly dependent on the width and depth of the surface geometry.