Fractal-Percolation Structure Architectonics in Sol-Gel Synthesis

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Porous materials with hierarchical fractal-percolation structures are crucial in various applications.
• Characterizing micro- and mesopores, especially those below a few nanometers, presents significant challenges with conventional methods.
• The sol-gel method offers a versatile route for synthesizing such complex porous materials.

Purpose of the Study:

• To develop a new technique for assessing micro- and mesopores with sizes below a few nanometers.
• To synthesize porous materials with hierarchical fractal-percolation structures using the sol-gel method.
• To propose a multimodal model for analyzing pore structures and percolation transitions.

Main Methods:

• Sol-gel synthesis involving tetraethoxysilane hydrolysis and polycondensation in the presence of metal oxide precursors.
• Material synthesis under spinodal decomposition conditions and thermal treatment.
• Characterization using atomic force microscopy, electron microscopy, and thermal desorption.
• Computer simulation of percolation transition using a multimodal model based on an enhanced Kepler net and Jullien fractal.

Main Results:

• Successfully synthesized porous materials with hierarchical fractal-percolation structures.
• Developed a novel multimodal model for pore structure analysis.
• Demonstrated the capability of the new technique to assess micro- and mesopores below a few nanometers.
• Identified limitations of atomic force microscopy and electron microscopy for analyzing these small pores.

Conclusions:

• A new, effective method for assessing sub-nanometer micro- and mesopores has been established.
• The sol-gel method combined with spinodal decomposition is suitable for creating hierarchical porous structures.
• The proposed multimodal model provides a powerful tool for understanding percolation phenomena in these materials.