Design of Core-Shell Polylactic Acid (PLA) electrospun nanofibers as potential healing carriers

Abstract

This study intends to maximize the encapsulation rate of healing carriers in core-shell nanofibers to augment the healing capabilities of the nanofibers in laminated composites synthesized via coaxial electrospinning. Core-shell nanofibers fabricated at a high core flow rate yielded defective fibers due to an insufficiency of shell solution to encapsulate the core solution being ejected from the syringe. Hence, a core-to-shell flow rate of 6.7:1 was identified to be optimal with an encapsulation content of over 50% without affecting its morphology. Thermogravimetric and spectral analysis of the healing NF showed the degradation of each constituent and their respective peaks, confirming the presence of the core solution without any chemical reaction with the PLA shell wall. Release of healing agents was observed under SEM, and the self-healing traits of the nanofibers were studied by subjecting them to repeated loadings under tension with significant strength retention without failure after four load cycles making these nanofibers highly valuable as a secondary reinforcement in polymer composites due to the nanofibers’ toughening and healing capabilities.