Low field NMR spin-lattice relaxation measurements of pore fluids contained in silica gels are employed as a pore structure probe to ascertain the changes that occur in a two-step acid/base-catalyzed silica gel during aging in its mother liquor. It has been shown that both a narrowing of pore size distribution and an increase in mean pore size is obtained for a gel aged at 303 K over a time per...

During last years the interest for nanotechnology and mesoporous silica materials has increased due to benefits that these materials can provide. Typical characteristics of mesoporous materials are a large surface area and pore volume, well-ordered and uniform pores with adjustable pores between 2 and 50 nm. Pore dimensions are comparable to many biological molecules, like enzymes, and may ther...

We shed light on the specific hydration structure around a zinc ion of nanosolution restricted in a cylindrical micropore of single-wall carbon nanotube (SWNT) by comparison with the structure restricted in a cylindrical mesopore of multi-wall carbon nanotube (MWNT) and that of bulk aqueous solution. The average micropore width of open-pore SWNT was 0.87 nm which is equivalent to the size of a ...

New forms of vanadium oxide Nanoporous were fabricated using a simple chemical synthesis method. Vanadium pentoxide (V2O5) Nanoporous were synthesized by sodium metavanadate as precursor and ethylene glycol as surfactant. The samples were characterized by high resolution transmission electron microscopy (HRTEM), field effect scanning electron microscopy (FESEM) and X-ray diffraction (XRD), Four...

Soot was harvested from five combustion sources: a dodecane flame, marine and bus diesel engines, a wood stove, and an oil furnace. The soots ranged from 20% to 90% carbon by weight and molar C/H ratios from 1 to 7, the latter suggesting a highly condensed aromatic structure. Total surface areas (by nitrogen adsorption using the Brunauer Emmett Teller, BET method) ranged from 1 to 85 m2 g(-1). ...

The use of NMR spin-lattice relaxation experiments on water, or other proton-containing fluids, in a porous solid as a pore structure/size measurement tool has been recently reported for porous solids with pore size greater than ~ 5 nm. This approach has numerous advantages, as compared to nitrogen sorption/ condensation and mercury porosimetry, including no network/percolation effects, no pore...