In this paper, mesoporous alumina with different pore sizes and wall crystalline structures was synthesized at calcination temperatures over 550 degrees C. The characterization of the samples calcined at 550, 800, 1100, and 1300 degrees C, respectively, was performed using TEM, XRD, FTIR, TG/DTA, and N2 adsorption/desorption techniques. The correlation between pore size and wall crystalline str...

The microstructure of coagulated colloidal particles, for which the interparticle potential is described by the Derjaguin-Landau-Verweg-Overbeek theory, is strongly influenced by the particles' surface potential. Depending on its value, the resulting microstructures are either more "homogeneous" or more "heterogeneous," at equal volume fractions. An adequate quantification of a structure's degr...

The accuracy of pore size distributions (PSD) obtained from gas adsorption and cryoporometry is compromised by the presence of advanced adsorption and advanced melting effects, respectively. In order to improve PSD accuracy, it is necessary to know the extent of such effects. In this work cryoporometry and adsorption have been combined to study the onset of advanced melting effects in a sample ...

The determination of the mean survival time t ~i.e., inverse reaction rate! associated with diffusion-controlled reactions among static traps is a problem of long-standing interest, dating back to the classical work of Smoluchkowski. For the broad class of model particulateand digitized-based models considered here, we find a universal curve for the mean survival time t for a wide range of poro...

Considerable research efforts have been used in the development of floating drug delivery system including gas generation system, swelling systems and low density systems. In the development of low density systems the porous carriers are used because of its characteristics such as stable uniform porous structure, high surface area, tunable pore size and well-defined surface properties. This rev...

Increased attention is being focused on metal-organic frameworks as candidates for hydrogen storage materials. This is a result of their many favorable attributes, such as high porosity, reproducible and facile syntheses, amenability to scale-up, and chemical modification for targeting desired properties. A discussion of several strategies aimed at improving hydrogen uptake in these materials i...

An a.c. calorimetric study has been carried out on octylphenylthiolpentyloxybenzoate (8ÂS5) in three silica aerogels with mass densities r=0 0́8, 0 1́7 and 0 3́6 g cm Õ 3 . Results for the least porous aerogel (r=0 3́6) are completely consistent with those reported previously for 8CB in the same aerogel. Freezing of 8ÂS5 damaged the more porous r=0 0́8 and 0 1́7 aerogels by creating internal voids an...

Polycarbonate Nuclepore filters are better than cellulose filters for the direct counting of bacteria because they have uniform pore size and a flat surface that retains all of the bacteria on top of the filter. Although cellulose filters also retain all of the bacteria, many are trapped inside the filter where they cannot be counted. Before use, the Nuclepore filters must be dyed with irgalan ...

The average pore size ξ0 of filamentous networks assembled from biological macromolecules is one of the most important physical parameters affecting their biological functions. Modern optical methods, such as confocal microscopy, can noninvasively image such networks, but extracting a quantitative estimate of ξ0 is a nontrivial task. We present here a fast and simple method based on a two-dimen...

MCM-41 particles were synthesized using inorganic raw materials and  Cetyltrimethylammonium bromide (CTAB). The textural properties and structure of MCM-41 particles were characterized by XRD, SEM, TEM and N2 adsorption-desorption methods. To study performance of Dubinin-Astakhov and Dubinin-Raduchkevic isotherm models in evaluating mesopore volume and pore size of MCM-41 samples, the mesopore ...