Adsorption Hysteresis in Open Slit-like Micropores

Area of Science:

• Physical Chemistry
• Materials Science
• Thermodynamics

Background:

• Low-pressure hysteresis (LPH) is under-researched, hindering optimization of applications like heat storage.
• Understanding LPH is crucial for advancing materials science and energy technologies.

Purpose of the Study:

• To develop and apply thermodynamically based models for analyzing low-pressure hysteresis.
• To investigate the adsorption and desorption processes using fractal geometry and irreversible thermodynamics.

Main Methods:

• Development of two thermodynamically based approaches for LPH analysis.
• Application of fractal geometry to characterize adsorption and desorption branches.
• Utilizing the degree of irreversibility as a control parameter in generalized equations.

Main Results:

• Accurate description of both adsorption and desorption branches using the developed methods.
• Demonstration that the fractal dimension of adsorption exceeds that of desorption.
• Indication of a more symmetric adsorbate phase state during adsorption compared to desorption.

Conclusions:

• The developed thermodynamic and fractal models provide a robust framework for studying LPH.
• The observed difference in fractal dimensions highlights distinct characteristics of adsorption and desorption phases.
• Insights gained can inform the design and optimization of materials for applications sensitive to adsorption phenomena.