Mechanical reinforcement of polyetherimide with electrospun zirconia nanofibers

The durability of dental restorative materials remains a central challenge in dentistry, driving the search for composites with superior mechanical properties. In this study, zirconia (ZrO2) nanofibers were synthesized by electrospinning polyacrylonitrile/zirconyl chloride, followed by calcination at 1100?C to form crystalline monoclinic ZrO2. The nanofibers (~100 nm median diameter, 57 nm crystallite size) were uniformly dispersed in a polyetherimide (PEI) matrix at 1 wt% and 3 wt%. FTIR and XRD confirmed complete conversion to ZrO2, while microscopy showed good interfacial compatibility. Microindentation revealed significant hardness improvements (140% at 1 wt%, 163% at 3 wt%), attributed to rigid nanofibers restricting polymer mobility. These findings demonstrate the promise of electrospun ZrO2 nanofibers for mechanically robust PEI-based dental composites. This study, the first to report incorporation of ZrO2 nanofibers into a PEI matrix for dental applications, demonstrates a promising pathway for developing mechanically enhanced composites for restorative dentistry.