Structural and microstructural studies of montmorillonite-based multilayer nanocomposites

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Montmorillonite is an abundant material suitable for creating textured nanocomposites.
• The dispersant significantly influences the final structure of montmorillonite-based composites.

Purpose of the Study:

• To investigate the impact of carboxymethylcellulose (CMC) and chitosan (Ch) on montmorillonite nanocomposite structures.
• To compare the effects of polysaccharides versus sodium hexametaphosphate on composite film properties.

Main Methods:

• Particle size analysis
• Rheological measurements
• Thermogravimetric analysis
• X-ray diffraction
• Scanning electron microscopy
• Flexural properties testing

Main Results:

• Additive choice dictates film structure and microstructure.
• Montmorillonite/sodium hexametaphosphate films exhibit high organization and toughness due to exfoliated, layered microstructures.
• Polysaccharide additives (CMC, Ch) result in particle agglomeration via competing surface adsorption and intercalation mechanisms.

Conclusions:

• The dispersant is critical in determining the microstructure and properties of montmorillonite nanocomposites.
• Sodium hexametaphosphate promotes an ordered, tough film structure.
• Polysaccharides lead to agglomeration, suggesting tailored applications based on desired microstructure.