Moisture-Resistant, High-Performance Polarizing Films via Aligned PMMA/CNT Composite Fibers: A Scalable Electrospinning Approach

Traditional iodine-based polyvinyl alcohol (PVA) polarizers encounter considerable durability challenges, especially in humid conditions, due to poor moisture resistance. This study presents an innovative organic-inorganic composite film composed of poly(methyl methacrylate) (PMMA) and carbon nanotubes (CNTs), fabricated via electrospinning, solvent vapor annealing (SVA), and uniaxial stretching. Pre-aligned PMMA/CNT composite fibers were electrospun and underwent SVA to stabilize the structure and reduce inter-fiber porosity. Further uniaxial stretching aligned the CNTs, enhancing optical anisotropy and polarization performance. The optimized parameters, 45 min of SVA and 75% stretching strain, produced composite films with a polarization degree exceeding 60%, which was combined with exceptional moisture resistance (<2% weight variation under 90% relative humidity). The integration of CNTs enhanced mechanical stability while preserving alignment during post-processing, thereby tackling the crucial challenge of scalable nanomaterial orientation. This study provides a scalable, cost-effective approach for developing durable polarizing materials with enhanced performance for optical devices in demanding environments.