Extraction of Biosilica Nanoparticles from Bamboo Leaves for Reinforcing Polyethersulfone (PES) Composites: Mechanical and Thermal Investigations

ABSTRACT

Polyethersulfone (PES) is a high‐performance engineering polymer with excellent thermal resistance, but its mechanical performance requires further improvement for demanding applications. This study investigated bamboo leaf‐derived biosilica as a reinforcing filler for PES, focusing on the effects of 3‐aminopropyltriethoxysilane (APTES) surface functionalization and filler loading. Nano‐biosilica was extracted from Vietnamese bamboo leaves via a sol–gel process and functionalized with APTES. The biosilica was characterized by XRD, FTIR, FE‐SEM, EDX, TEM, BET, and TGA, then was incorporated into PES by melt blending at 1–7 wt.%, with 5 wt.% epoxy resin used as a processing aid. TEM revealed average particle diameters of 40.17 ± 2.33 nm for pristine biosilica and 41.72 ± 1.35 nm for APTES‐modified biosilica. EDX detected C and N after APTES treatment, supporting successful surface functionalization. APTES modification improved biosilica dispersion and reduced agglomeration in PES matrix. Among the investigated compositions, 5 wt.% APTES‐modified biosilica provided the best overall mechanical performance, increasing tensile strength and impact strength to 97.52 MPa and 9.63 kJ/m ² , respectively, compared with 74.08 MPa and 6.55 kJ/m ² for the control. The PES/modified‐biosilica composites also exhibited enhanced thermal stability. These results demonstrate the potential of bamboo leaf‐derived biosilica for reinforcing high‐performance PES composites.