Equilibrium adsorption on single and aggregated nanospheres

Area of Science:

• Physical Chemistry
• Materials Science
• Nanotechnology

Background:

• Understanding gas adsorption on nanostructured materials is crucial for applications like gas storage and separation.
• The behavior of adsorption on curved surfaces differs significantly from planar surfaces, especially at the nanoscale.

Purpose of the Study:

• To investigate argon (Ar) adsorption on single and double carbon dioxide (CO2) nanospheres using mean field density functional theory (MFDFT).
• To analyze the influence of nanosphere size and configuration on adsorption isotherms, density profiles, and phase transitions.

Main Methods:

• Employed mean field density functional theory (MFDFT) to model Ar adsorption.
• Simulated adsorption from subsaturation to saturation conditions across various temperatures.
• Analyzed adsorption excess, density profiles, and adsorption transitions for single and double nanosphere systems.

Main Results:

• For single nanospheres, adsorption behavior and density profiles converge to those of planar surfaces as sphere size increases.
• The transition from thin-film to thick-film adsorption is highly dependent on substrate size, approaching planar behavior for large spheres.
• In the double sphere system, clustering preferentially occurs in the interstitial region between the spheres, but does not influence the adsorption transition.

Conclusions:

• Nanosphere size is a critical factor determining the transition from spherical to planar adsorption behavior.
• The presence of two adjacent nanospheres enhances interstitial clustering but does not fundamentally alter the adsorption phase transition.
• MFDFT provides a valuable framework for understanding gas adsorption phenomena at the nanoscale.