Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Mechanical Engineering

Committee Chair/Advisor

Hongseok Choi

Committee Member

Zhaoxu Meng

Committee Member

Srikanth Pilla

Committee Member

Xin Zhao


Understanding the complexity of changes in a polymer solution through the addition of nanoparticles and the process used to prepare the solutions is vitally important to obtain desirable characteristics of electrospun nanofibers such as degree of crystallinity, morphological, thermal and mechanical properties. Although there have been significant efforts in this research area, a more in-depth understanding on how nanoparticles can affect the formation of polymeric structures during electrospinning is still needed to ensure overall quality and performance of the nonwoven material. The present study aimed to specifically explore the relationship between solution processing method, nanoparticle volume fraction, and solution properties on electrospun nanofiber formation and associated physical properties of the nanocomposite nanofiber nonwoven mat. The research consisted of controlled experimental methods to implement an ultrasonic processing method to produce poly(ethylene oxide)(PEO) solutions and study the influence of silicon carbide (SiC) nanoparticle addition on the solution properties, the electrospinning process and the nonwoven material performance. The electrical conductivity of PEO solutions was found to increase upon the addition of SiC nanoparticles (3 wt%). The significant increase in the electrical conductivity of the solution as a result of the addition of SiC, resulted in nanocomposite nanofibers with reduced average diameter and diameter distribution. Differential scanning calorimetry (DSC) and X-Ray Diffraction (XRD) was used to study the crystal structure of the as-spun neat PEO nanofibers and PEO-SiC nanocomposite nanofibers. The DSC curves indicated an increase in local percent crystallinity of PEO-SiC nanocomposite nanofibers compared to neat PEO nanofibers. This suggests that the addition of SiC enhanced the crystallization behavior by serving as nucleation sites and by providing a higher charge carrying capacity of the solution jet (i.e. more stretching). Thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FTIR) was used to investigate decomposition profiles and possible intermolecular interactions between PEO chains and SiC nanoparticles. Finally, the tensile properties of the PEO-SiC nanocomposite nanofibers were compared against neat PEO nanofibers fabricated under consistent electrospinning conditions. Uniaxial tensile testing of the nanofibers showed that the ultimate tensile strength (UTS) of PEO-SiC nanocomposite nanofibers was increased, compared to neat PEO nanofibers, which is attributed to the influence SiC nanoparticles had on the crystallization behavior of the jet during electrospinning. These investigations also provide strong support regarding the effectiveness of ultrasonic processing for electrospinning of polymer nanocomposite nanofibers with high concentrations of reinforcement nanoparticles. The research performed in this work will serve as a baseline for future work on scaling up the fabrication of novel nanocomposite nanofibers with enhanced mechanical and physical properties.

Available for download on Saturday, May 31, 2025

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