Heterogeneous three-dimensional mesoporous networks (A. J. Ramírez-Cuesta, S. Cordero, F. Rojas, R. J. Faccio and J. L. Riccardo, J. Porous Mater., 2001, 8, 61, ) constructed under the premises of the dual site–bond model have been used as probe substrates to study the effects of variable connectivity and pore-size correlation on the aspects of both hysteresis loops and primary sorption scanning curves. The shapes of the hysteresis loops obtained from sorption simulation in networks of diverse morphologies are compared and discussed. It is found that the precursor structural parameters of the Monte Carlo simulated networks together with the sorption algorithm used in this work, can lead to IUPAC types H1, H2 and H3-like hysteresis loops, depending on the values chosen for the pore-size distribution parameters and mean connectivity. Network morphology also influences greatly the mechanisms of sorption processes in poorly or highly size correlated porous substrates. Sorption results on these 3-D porous specimens help to visualize the extents of pore blocking (vapour percolation) and delayed adsorption (liquid percolation) phenomena and also to foresee the most appropriate methods to ascertain the structure of porous materials.

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The isosteric enthalpy of adsorption (${\Delta }_{ads}\dot{h}$) of CO₂ in three different micro and mesoporous materials was evaluated in this work. These materials were a microporous material with functional groups of nitrogen and oxygen (CMFs, carbon microfibers), a mesoporous material with silanol groups (SBA-15, Santa Barbara Amorphous), and a mesoporous material with amine groups (SBA-15_APTES, SBA-15 amine-functionalized with (3-Aminopropyl)-triethoxysilane). The temperature interval explored was between 263 K and 303 K, with a separation of 5 K between each one, so a total of nine CO₂ isotherms were obtained. Using the nine isotherms and the Clausius–Clapeyron equation, the reference value for ${\Delta }_{ads}\dot{h}$ was found. The reference value was compared with those ${\Delta }_{ads}\dot{h}$ obtained, considering some arrangement of three or five CO₂ isotherms. Finally, it was found that at 298 K and 1 bar, the total amount of CO₂ adsorbed is 2.32, 0.53, and 1.37 mmol g⁻¹ for CMF, SBA-15, and SBA-15_APTES, respectively. However, at a coverage of 0.38 mmol g⁻¹, ${\Delta }_{ads}\dot{h}$ is worth 38, 30, and 29 KJ mol⁻¹ for SBA-15_APTES, CMFs, and SBA-15, respectively. So, physisorption predominates in the case of CMF and SBA-15 materials, and the ${\Delta }_{ads}\dot{h}$ values significantly coincide regardless of whether the isotherms arrangement used was three or five. Meanwhile, in SBA-15_APTES, chemisorption predominates as a consequence of the arrangements used to obtain ${\Delta }_{ads}\dot{h}$. This happens in such a way that the use of low temperatures (263–283 K) tends to produce higher ${\Delta }_{ads}\dot{h}$ values, while the use of high temperatures (283–303 K) decreases the ${\Delta }_{ads}\dot{h}$ values.

High-porosity nanostructured amorphous tungsten OXIDE (a-WO₃) films were synthesized by a Hot Filament Chemical Vapor Deposition technique (HFCVD) and then transformed into a crystalline WO₃ by simple thermal annealing. The a-WO₃ films were annealed at 100, 300, and 500 °C for 10 min in an air environment. The films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), micro-Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and UV–vis spectroscopy. Results revealed that the a-WO₃ films were highly porous, composed of cauliflower-like structures made of nanoparticles with average sizes of 12 nm. It was shown that the effect of annealing on the morphology of the a-WO₃ films leads to a sintering process. However, the morphology is conserved. It was found that at annealing temperatures of 100 °C, the a-WO₃ films are of an amorphous nature, while at 300 °C, the films crystallize in the monoclinic phase of WO₃. The calculated bandgap for the a-WO₃ was 3.09 eV, and 2.53 eV for the film annealed at 500 °C. Finally, the results show that porous WO₃ films preserve the morphology and maintain the porosity, even after the annealing at 500 °C.