Water Adsorption–Desorption Behavior of Two-Dimensional Hexagonal Mesoporous Silica around Freezing Point

The adsorption–desorption isotherms of water on mesoporous silicas (MPSs) with pore diameters of ∼3.8 and ∼9.1 nm were measured at 253–283 K using a volumetric method. Type V adsorption–desorption isotherms with significant hysteresis were obtained for both MPSs. In the MPS with 3.8 nm pore diameter, complete pore filling with water occurred near the saturated vapor pressure, over the entire temperature range, whereas capillary condensation was initiated at higher relative pressure with decreasing temperature. In the MPS with 9.1 nm pore diameter, complete pore filling with water occurred at 263 K and above, whereas the measured equilibrium pressure reached the saturation vapor pressure of bulk water at 258 K and below, before reaching the pore filling state. To clarify the delay of capillary condensation and the pore blocking of ice, the kinetics of water adsorption was evaluated by analyzing the pressure relaxation curve up to the equilibrium pressure using a sample cell. Furthermore, the curvature radius where capillary evaporation occurs was evaluated by the Gibbs–Tolman–Koening–Buff (GTKB) and Kelvin equations. The calculated curvature radius were 1.5 and 4.0 nm for 3.8 and 9.1 nm diameter mesopores, respectively, and these values were independent of temperature

Adsorption and Desorption of Water in Two-Dimensional Hexagonal Mesoporous Silica with Different Pore Dimensions

We have investigated the adsorption and desorption of water in two-dimensional hexagonal mesoporous silica (MPS) with three different pore dimensions. All the adsorption–desorption isotherms exhibited type V behavior with significant hysteresis. Hysteresis was observed in the transient region between the layer adsorption state and the pore filling state, where capillary condensation and evaporation occurred. When the relative humidity is changed in steps from the onset point of capillary condensation and capillary evaporation, the relaxation curves of water uptake and release were measured at 298 K using a gravimetric method. For all MPSs, the relaxation rates of water uptake and release increased as the magnitude of the stepwise change in relative humidity increased. The relaxation curves of some MPSs could be well fitted by the exact solution of the Fickian diffusion equation at a small stepwise change in relative humidity. On the other hand, the adsorbed mass is proportional to the square root of time at large stepwise changes in relative humidity. The relationship between the mass flux of water uptake or release and the difference in chemical potential between the initial and final states of moist gases depends on the structural properties of the mesopores

Effect of Withdrawal Speed on Film Thickness and Hexagonal Pore-Array Dimensions of SBA-15 Mesoporous Silica Thin Film

Two-dimensional hexagonal mesoporous silica thin films of SBA-15 were synthesized on Si substrates via dip-coating using an evaporation-induced self-assembly process. The effect of the withdrawal speed on the thicknesses, one-dimensional pore alignments, and two-dimensional hexagonal pore arrays of the films was elucidated. Detailed analyses of FE-SEM and TEM images and XRD and XRR patterns of the synthesized thin films clarified that the pore sizes, interplanar spacings, and film thicknesses depend on the withdrawal speed. Furthermore, the same films were synthesized on Si substrates with microtrenches. The local flow of coating solutions around microtrenches affects the pore direction as well as the film thickness. In order to form well-ordered mesoporous silica thin films with large surface areas, it is important to control the synthetic conditions such as the local flow of the coating solutions as well as the physicochemical properties of the silica precursor solutions or template molecules

MOESM1 of Comparative effectiveness of elemental formula in the early enteral nutrition management of acute pancreatitis: a retrospective cohort study

Additional file 1. Severity Scoring System for Acute Pancreatitis of the Japanese Ministry of Health, Labour and Welfare (2008)

Ion Transport in Mesoporous Silica SBA-16 Thin Films with 3D Cubic Structures

Mesoporous silica SBA-16 thin films with highly ordered 3D cubic structures were synthesized on a Si substrate via the dip-coating method. After these films were filled with KCl aqueous solutions, the ionic current passing through the mesopores was measured by applying dc electric fields. At low ion concentrations, the measured <i>I</i>–<i>V</i> curves were nonlinear and the current increased exponentially with respect to voltage. As the ion concentration increased, the <i>I</i>–<i>V</i> curve approached linear behavior. The nonlinear behavior of <i>I</i>–<i>V</i> curves can be reasonably attributed to the electric potential barrier created in nanopores

MOESM7 of Comparative effectiveness of elemental formula in the early enteral nutrition management of acute pancreatitis: a retrospective cohort study

Additional file 7. Recommendations in clinical practice guidelines for the type of formulae in acute pancreatitis

Targeted Synthesis of Heterobimetallic Compounds Containing a Discrete Vanadium(V)−μ-Oxygen–Iron(III) Core

Heterobimetallic compounds [L¹OV^VO→Fe­(metsalophen)­(H₂O)] (<b>1</b>) and [L²OV^VO→Fe­(metsalophen)­(H₂O)]­CH₃CN (<b>2</b>), where H₂L¹ and H₂L² are tridentate dithiocarbazate-based Schiff base ligands, containing a discrete V^V–μ-O–Fe^III angular core have been synthesized for the first time through a targeted synthesis route: confirmation in favor of such a heterobimetallic core structure has come from single-crystal X-ray diffraction analysis and electrospray ionization mass spectrometry

MOESM3 of Comparative effectiveness of elemental formula in the early enteral nutrition management of acute pancreatitis: a retrospective cohort study

Additional file 3. Mean prescription dose of elemental formula from the day of admission to day 14

MOESM4 of Comparative effectiveness of elemental formula in the early enteral nutrition management of acute pancreatitis: a retrospective cohort study

Additional file 4. Calibration plot

Targeted Synthesis of Heterobimetallic Compounds Containing a Discrete Vanadium(V)−μ-Oxygen–Iron(III) Core

Heterobimetallic compounds [L¹OV^VO→Fe­(metsalophen)­(H₂O)] (<b>1</b>) and [L²OV^VO→Fe­(metsalophen)­(H₂O)]­CH₃CN (<b>2</b>), where H₂L¹ and H₂L² are tridentate dithiocarbazate-based Schiff base ligands, containing a discrete V^V–μ-O–Fe^III angular core have been synthesized for the first time through a targeted synthesis route: confirmation in favor of such a heterobimetallic core structure has come from single-crystal X-ray diffraction analysis and electrospray ionization mass spectrometry