Adhesion anisotropy between contacting electrospun fibers

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Mechanical properties of electrospun fiber networks are crucial for applications like filtration and tissue engineering.
• Fiber-fiber adhesion within these networks significantly influences overall network performance.
• Electrospun networks feature diverse fiber contact configurations, including cross-cylinder and parallel arrangements.

Purpose of the Study:

• To quantify the work of adhesion between individual electrospun polyamide fibers.
• To investigate the influence of fiber contact orientation on adhesion.
• To elucidate the mechanisms governing adhesion in electrospun fiber networks.

Main Methods:

• In situ atomic force microscopy (AFM) was employed to measure adhesion forces.
• Controlled fiber orientations (cross-cylinder and parallel) were utilized.
• Measurable contact areas were established for precise quantification.

Main Results:

• The work of adhesion was found to be strongly dependent on the fiber-fiber contact configuration.
• Parallel fiber configurations exhibited significantly higher work of adhesion compared to cross-cylinder configurations.
• Adhesion varied with contact length in both configurations.

Conclusions:

• Electrospun fiber adhesion is direction-dependent, influenced by contact geometry.
• A polymer chain orientation mechanism, enhancing van der Waals interactions, is suggested.
• This highlights the inherent variability of adhesion in random electrospun fiber networks.