Modus operandi of controlled release from mesoporous matrices: a theoretical perspective

Area of Science:

• Materials Science
• Chemical Engineering
• Physical Chemistry

Background:

• Controlled release from mesoporous materials is vital for applications like drug delivery.
• Previous studies demonstrated control over release rates via material properties, but mechanisms remained unclear.
• The specific roles of pore size and molecule-wall interactions were not fully understood.

Purpose of the Study:

• To elucidate the fundamental mechanisms governing controlled release from mesoporous materials.
• To investigate the influence of pore size and molecule-wall attractions on release kinetics.
• To provide a theoretical framework explaining experimental observations.

Main Methods:

• Development of a simplified 2-dimensional (2D) model of ordered porous matrices.
• Numerical solution of the 2D Fokker-Planck equation for various initial concentration distributions.
• Systematic variation of pore size and molecule-wall attraction strengths.

Main Results:

• Molecule-wall interactions significantly impact controlled release, irrespective of material functionalization.
• These interactions define the effective cross-section for molecule transfer to the bulk solution.
• Inclusion of molecule-wall attractions successfully explains the observed pore-size dependence of release kinetics.

Conclusions:

• Molecule-wall attractions are a fundamental factor in controlled release from mesoporous materials.
• The developed model provides a revised understanding of release mechanisms, reconciling theory and experiment.
• This work offers insights for optimizing mesoporous materials for targeted release applications.