Effects of water on the stochastic motions of propane confined in MCM-41-S pores

Gautam, Siddharth; Le, Tran Thi Bao; Rother, Gernot; Jalarvo, Niina; Liu, Tingting; Mamontov, Eugene; Dai, Sheng; Qiao, Zhen‐An; Striolo, Alberto; Cole, David R.

doi:10.1039/c9cp04741g

Cited by 20 publications

(16 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results confirm that the presence of water strongly impedes the transport of propane across the hydrated pores, in qualitative agreement with prior simulations, and also with expectations. A similar damping of propane mobility due to presence of D 2 O in MCM-41-S has also been observed in quasielastic neutron scattering experiments . Unfortunately, only a qualitative comparison can be made, because the experiments were conducted at lower temperatures than the simulations presented here.…”

Section: Simulation Resultssupporting

confidence: 73%

“…A similar damping of propane mobility due to presence of D 2 O in MCM-41-S has also been observed in quasielastic neutron scattering experiments. 31 Unfortunately, only a qualitative comparison can be made, because the experiments were conducted at lower temperatures than the simulations presented here.…”

Section: Simulation Resultsmentioning

confidence: 98%

“…The present work stems from recent quasi-elastic neutron scattering experiments conducted for systems containing propane confined in MCM-41-S materials. 31 These experimental results showed that propane mobility decreases as the D 2 O content increases. To probe a system similar to the experimental one, in this manuscript we consider propane–water mixtures confined inside a 16 Å diameter cylindrical silica pore.…”

Section: Introductionmentioning

confidence: 89%

“…Toward this goal, our group previously reported molecular dynamics (MD) simulations that documented the effect of density and composition of CO 2 -hydrocarbon mixtures on adsorption and mobility of the confined mixtures. , Those simulation results, which seem to be in agreement with experimental observations, − suggest that the preferential CO 2 adsorption to the pore walls weakens the adsorption of hydrocarbons, and enhances the self-diffusion of hydrocarbons via lowering the activation energy for diffusion. The present work stems from recent quasi-elastic neutron scattering experiments conducted for systems containing propane confined in MCM-41-S materials . These experimental results showed that propane mobility decreases as the D 2 O content increases.…”

Section: Introductionmentioning

confidence: 96%

See 3 more Smart Citations

Propane–Water Mixtures Confined within Cylindrical Silica Nanopores: Structural and Dynamical Properties Probed by Molecular Dynamics

Striolo

Gautam

et al. 2017

Langmuir

Self Cite

View full text Add to dashboard Cite

Despite the multiple length and time scales over which fluid-mineral interactions occur, interfacial phenomena control the exchange of matter and impact the nature of multiphase flow, as well as the reactivity of C–O–H fluids in geologic systems. In general, the properties of confined fluids, and their influence on porous geologic phenomena are much less well understood compared to those of bulk fluids. We used equilibrium molecular dynamics simulations to study fluid systems composed of propane and water, at different compositions, confined within cylindrical pores of diameter ∼16 Å carved out of amorphous silica. The simulations are conducted within a single cylindrical pore. In the simulated system all the dangling silicon and oxygen atoms were saturated with hydroxyl groups and hydrogen atoms, respectively, yielding a total surface density of 3.8 −OH/nm2. Simulations were performed at 300 K, at different bulk propane pressures, and varying the composition of the system. The structure of the confined fluids was quantified in terms of the molecular distribution of the various molecules within the pore as well as their orientation. This allowed us to quantify the hydrogen bond network and to observe the segregation of propane near the pore center. Transport properties were quantified in terms of the mean square displacement in the direction parallel to the pore axis, which allows us to extract self-diffusion coefficients. The diffusivity of propane in the cylindrical pore was found to depend on pressure, as well as on the amount of water present. It was found that the propane self-diffusion coefficient decreases with increasing water loading because of the formation of water bridges across the silica pores, at sufficiently high water content, which hinder propane transport. The rotational diffusion, the lifespan of hydrogen bonds, and the residence time of water molecules at contact with the silica substrate were quantified from the simulated trajectories using the appropriate autocorrelation functions. The simulations contribute to a better understanding of the molecular phenomena relevant to the behavior of fluids in the subsurface.

show abstract

Section: Simulation Resultssupporting

confidence: 73%

Section: Simulation Resultsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 96%

See 2 more Smart Citations

Propane–Water Mixtures Confined within Cylindrical Silica Nanopores: Structural and Dynamical Properties Probed by Molecular Dynamics

Striolo

Gautam

et al. 2017

Langmuir

Self Cite

View full text Add to dashboard Cite

show abstract

“…The role of water on propane diffusion in silica nanopores was recently discussed in detail, in which molecular dynamics simulations and QENS (quasielastic neutron scattering) were used to reveal that water restricts propane motion and self-diffusion at high loadings. , The silica nanopores in that work were smaller than the 10 nm average pore size used here, i.e., 1.6 nm, and results indicated that propane became entrapped by water in the center of the pores, not near the walls. It is not possible to rule out that cyclohexane may also become entrapped by water at positions away from the pore wall, contrary to what is depicted in Figure .…”

Section: Resultsmentioning

confidence: 76%

Diffusion, Interactions, and Disparate Kinetic Trapping of Water–Hydrocarbon Mixtures in Nanoporous Solids

et al. 2021

View full text Add to dashboard Cite

Mixed fluids confined in porous solid hosts present challenges for the accurate characterization of individual-component behavior. NMR diffusometry with chemical resolution is used to identify unexpected loading-and composition-dependent anomalous diffusion in water/cyclohexane mixtures confined to solid nanoporous glass (NPG) hosts. Diffusion NMR results indicate that data obtained on pure-component liquids in confinement cannot be extrapolated to their nonideal liquid mixtures confined in the same solid host. Loading-dependent data must be obtained on each component in the confined mixture in order to determine which of the liquid components exhibits chemical affinity for the host and, conversely, which of the components exhibits anomalous diffusivity. Most notably, NMR diffusometry revealed that cyclohexane diffusivity varied by 2 orders of magnitude in a water-rich mixture depending on the total fluid loading in the NPG host, ranging from anomalously high diffusivities that significantly exceeded that for pure cyclohexane in NPG at low fluid loadings to kinetically trapped sequestration at high fluid loadings. NMR diffusometry indicates that nonideal solution behavior in fluids confined within nanoporous hosts may have practical implications for enhanced oil recovery methods. Specifically, kinetic trapping of hydrocarbons in water-flooding regimes can result from complex liquid−vapor equilibrium that is significantly perturbed from that which exists in bulk or microporous confinement.

show abstract

Physical and Chemical Interactions of the Polar and Nonpolar Solvents on the Mesoporous Silica Material to Developing Solvent Sensors.

et al. 2023

View full text Add to dashboard Cite

This work examines the physical and chemical interactions between the polar and nonpolar solvents and the surface of the MCM‐41 material, which serves as the isolating layer, employing sensing capacitance‐voltage measurements with a Metal‐Insulator‐Semiconductor (MIS) capacitor. It was observed that the MCM‐41 surface is more sensitive to methanol, which is a protic solvent, than to other nonpolar solvents like chloroform, according to the data. Furthermore, by analyzing the interaction of the methanol with the surface of MCM‐41 as a function of the applied field, the electron transfer, and the orientation of the solvent molecule, DFT Calculations using the Siesta simulation software enable us to assess this sensitivity. Based on the performance of MCM‐41 as the insulator in the MIS capacitor, MCM‐41 has a strong potential for the creation of high‐sensitivity sensors for solvent detection avoiding the functionalization process.

show abstract

Effects of water on the stochastic motions of propane confined in MCM-41-S pores

Abstract: Quasi-elastic neutron scattering (QENS) and molecular dynamics simulations (MDS) reveal the effects of water on the structure and dynamics of propane confined in 1.5 nm wide cylindrical pores of MCM-41-S.

Cited by 20 publications

References 46 publications

Propane–Water Mixtures Confined within Cylindrical Silica Nanopores: Structural and Dynamical Properties Probed by Molecular Dynamics

Propane–Water Mixtures Confined within Cylindrical Silica Nanopores: Structural and Dynamical Properties Probed by Molecular Dynamics

Diffusion, Interactions, and Disparate Kinetic Trapping of Water–Hydrocarbon Mixtures in Nanoporous Solids

Physical and Chemical Interactions of the Polar and Nonpolar Solvents on the Mesoporous Silica Material to Developing Solvent Sensors.

Contact Info

Product

Resources

About