Combined dip- and spin-coating for functionalizing polymeric nonwovens via Fiber-nanoparticle electrostatic...

Controlled deposition of TiO₂ nanoparticles onto polypropylene nonwoven fabrics was achieved by tuning electrostatic interactions through pH-dependent zeta potential adjustments. Oppositely charged fiber and particle surfaces promote effective adhesion, with surface coverage strongly impacted by the ionic composition of the dispersion medium. Centrifugal drying minimizes capillary-induced agglomeration, leading to more uniform coatings compared to passive evaporation. SEM observations confirm that finer fibers support more homogeneous nanoparticle layers, while coarser fibers exhibit discontinuous coverage. Computational simulations support experimental results, indicating that opposite surface charges are essential for efficient deposition, while fiber diameter plays a key role in determining coating kinetics. The resulting coatings demonstrate high stability under both ultrasonic and flow washing, underscoring their suitability for use in dynamic environments such as photocatalytic flow systems.