RESUMO
Porous liquids (PLs) are attractive materials because of their capability to combine the intrinsic porosity of microporous solids and the processability of liquids. Most of the studies focus on the synthesis of PLs with not only high porosity but also low viscosity by considering their transportation in industrial plants. However, a gap exists between PLs and solid adsorbents for some practical cases, where the liquid characteristics and mechanical stability without leakage are simultaneously required. Here, we fill in this gap by demonstrating a new concept of pore-networked gels, in which the solvent phase is trapped by molecular networks with accessible porosity. To achieve this, we fabricate a linked metal-organic polyhedra (MOPs) gel, followed by exchanging the solvent phase with a bulky liquid such as ionic liquids (ILs); the dimethylformamide solvent trapped inside the as-synthesized gel is replaced by the target IL, 1-butyl-3-methylimidazolium tetrafluoroborate, which in turn cannot enter MOP pores due to their larger molecular size. The remaining volatile solvents in the MOP cavities can then be removed by thermal activation, endowing the obtained IL gel (Gel_IL) with accessible microporosity. The CO2 capacities of the gels are greatly enhanced compared to the neat IL. The exchange with the IL also exerts a positive influence on the final gel performances such as mechanical properties and low volatility. Besides ILs, various functional liquids are shown to be amenable to this strategy to fabricate pore-networked gels with accessible porosity, demonstrating their potential use in the field of gas adsorption or separation.
RESUMO
Isosteric heat of adsorption is exquisitely sensitive to structural changes in carbon surfaces based on the energetic behavior of the interactions between adsorbates and carbon materials. We discuss the relationships between porous structures, oxygen functional groups, and heat of adsorption based on the behavior of the heat of adsorption of polar and non-polar fluids on porous carbon materials with oxygen functional groups. The porosity and functional groups of porous carbon materials were estimated from N2 adsorption isotherms at 77â¯K and temperature-programmed desorption. High-resolution adsorption isotherms of water, acetonitrile (polar fluid), and n-hexane (non-polar fluid) were measured on porous carbon materials with different pore size distributions and amounts of oxygen functional groups at various temperatures. The heats of adsorption were determined by applying the Clausius-Clapeyron equation to the adsorption isotherms. The heat of adsorption curves directly reflect the effects of interactions of fluid-oxygen functional groups, fluid-basal planes of pore walls, and fluid-fluid interfaces. In particular, the heat of adsorption curve of water is very sensitive to surface oxygen functional groups. This finding indicates the possibility of estimating the relative amounts of oxygen functional groups on porous carbon materials based on the amounts of water adsorbed at specific relative pressures.
RESUMO
The presence or absence of metastasis has critical implications for therapeutic decision-making in urothelial cancer (UC). Conventional magnetic resonance imaging (MRI) utilizing anatomic T1- and T2-weighted images has modest efficacy in detecting lymph node and distant metastases in UC. However, incorporation of functional techniques including diffusion weighted imaging and dynamic contrast-enhanced imaging, may improve the accuracy of lesion detection and staging. Multiparametric (mp)MRI is widely used in the imaging of prostate and breast cancers, though its usefulness in UC has yet to be fully elucidated. The present study reports on mpMRI in the context of two cases of bladder and ureteral cancer, and imaging results with pathological diagnosis.
