Optically transparent polyvinyl alcohol composite film obtained by self-reinforcing and self-toughening with electrospun polyvinyl alcohol nanofibers: A solution processing strategy

Optically transparent polyvinyl alcohol (PVA) films with high tensile strength and toughness are urgently needed in optical field. However, the combination of good optically transparency and excellent mechanical properties is still an obstacle for the PVA films. Herein, PVA composite film obtained by self-reinforcing and self-toughening with electrospun PVA nanofibers possessing various solubility via a solution strategy is proposed to tackle this challenge. The uniaxially aligned PVA nanofibers were electrospun by a narrow roller; thereafter, the PVA composite films were fabricated by solution impregnation technique and mould pressing. Owing to the strong interface binding, entangled molecular chains, and close refractive index between PVA nanofiber and PVA matrix, the as-prepared PVA-based composite film showed satisfactory light transmittance of above 85% in the 400-800 nm wavelength range with the tensile strength and elongation at break achieving 70 MPa and 160.1%. This work proposed a new solution-based strategy to efficiently fabricate PVA composite films for optical applications.