Glass fiber reinforced polymers (GFRPs) have drawn significant attention given their lightweight, mechanical resistance and tunable properties through constituent selection. Due to environmental concerns, research efforts have focused on incorporating sustainable materials, such as bio-epoxy resins, to reduce the ecological impact of GFRPs. This study characterizes a GFRP containing a bio-epoxy resin matrix, various loadings of titanium dioxide (TiO₂) nanoparticles, and a stabilized arrangement of glass fiber. The unreinforced composite exhibited a tensile strength and modulus of 214 MPa, and 13 GPa, respectively, and a flexural strength and modulus of 375 MPa and 14.5 GPa, respectively. The addition of TiO₂ produced an improvement in mechanical response for all the composites. The formulation with 1 wt.% TiO₂ showed the best tensile response with an improvement of 13% and 14% for its tensile strength, and modulus, respectively; meanwhile, the composites with 2 wt.% TiO₂ attained an improvement of 19% and 40% for the flexural strength and modulus, respectively. Scanning electron microscopy (SEM) revealed significant changes in the fracture mechanism of the composites, while energy-dispersive spectroscopy (EDS) confirmed an even nanoparticle distribution. Additionally, machine learning (ML) models were developed to predict the mechanical response as a function of the TiO₂ content.

Polymer matrix composites (PMCs) have garnered importance due to their unique combination of mechanical, thermal, and functional properties. However, their performance depends on overcoming challenges related to dispersion, bonding, and processing. Electrospinning is an advanced technique for producing nanofiber or microfiber PMCs. One of the key challenges in electrospun PMCs is the uniform dispersion of reinforcement materials like ${\mathrm{TiO}}_2$ nanoparticles within the polymer matrix. A Taguchi orthogonal design ($L_{16}$) was used to evaluate the effects of needle-to-collector distance, applied voltage, and flow rate on mean fiber diameter and deposition quality. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR) were used to characterize electrospun neat sulfonated poly(ether ether ketone) (sPEEK) and sPEEK/TiO₂ fibers, whereas tensile tests were performed on solution-cast membranes prepared from the corresponding formulations. The lowest observed run mean diameter was 204.6695 nm at 8 kV, 1.25 mL h⁻¹, and a needle-to-collector distance of 12 cm; this run was also selected for deposition quality. Neat sPEEK membranes exhibited a mean tensile strength of 35.3 MPa, a mean apparent tensile modulus of 476 MPa, and a mean elongation at fracture of 18%. Among the TiO₂-containing formulations, increasing the TiO₂ content from 0.04 to 0.10 wt.% was associated with higher mean apparent tensile modulus and tensile strength and lower mean elongation at fracture. The 0.10 wt.% formulation exhibited the highest mean apparent tensile modulus and tensile strength.