Effects of nanopore size on properties of modified inner surfaces

Paraffin confined in carbon nanotubes as nano-encapsulated phase change materials: experimental and molecular dynamics studies

The characteristics of paraffin confined in carbon nanotubes (CNTs) were investigated using experimental and molecular dynamics (MD) methods.

Effect of electric field on liquid infiltration into hydrophobic nanopores

Understanding the variation of nanofluidic behavior in the presence of an external electric field is critical for controlling and designing nanofluidic devices. By studying the critical infiltration pressure of liquids into hydrophobic nanopores using molecular dynamics (MD) simulations and experiments, important insights can be gained on the variation of the effective liquid-solid interfacial tension with the magnitude and sign of electric field, as well as its coupling with the pore size and the solid and liquid species. It is found that the effective hydrophobicity reduces with the increase of electric intensity and/or pore size, and the behavior is asymmetric with respect to the direction of the electric field. The underlying molecular mechanisms are revealed via the study of the density profile, contact angle, and surface tension of confined liquid molecules.

Eletrowetting effect in a nanoporous silica

In the past, electrowetting was usually analyzed on large solid surfaces. In the current study, the effective solid-liquid interfacial tension in a nanoporous silica, which is measured by the ion transport pressure, is investigated experimentally. The interfacial tension decreases as the applied potential difference increases, while the magnitude of variation is much smaller than its bulk counterpart. The effect of the external electric field is saturated at a relatively low voltage. These unique phenomena can be attributed to the confinement effect of nanopore walls.

Influence of anions on liquid infiltration and defiltration in a zeolite Y

In pure water a hydrothermally treated zeolite Y is hydrophilic, while with the addition of an electrolyte it can no longer be soaked up spontaneously. The effective degree of hydrophobicity increases with the ion concentration, which is reflected by the increase in infiltration pressure. The pressure-induced infiltration behavior is not only determined by the cations, but also highly dependent on the anion species. This phenomenon can be attributed to the confinement effect of nanopore walls.

Effects of the addition of electrolyte on liquid infiltration in a hydrophobic nanoporous silica gel

In this letter, we report the experimental results of pressure induced infiltration in the hydrophobic nanopores of a silica gel. The infiltration pressure increases with the prolonged surface treatment time, whereas the infiltration volume is not dependent on the surface coverage. When temperature increases, if the liquid phase is pure water, the infiltration pressure would decrease, which is in agreement with the classic contact angle measurement results at large solid surfaces. As an electrolyte is added, however, the variation in infiltration pressure is negligible over a broad temperature range.