Functionalized zinc oxide nanorods - polypropylene nonwoven composite with high biological and photocatalytic activity

This work presents a comprehensive approach to elaborating new active polypropylene-zinc oxide composite material with a well-developed specific surface area. Fibrous polypropylene material, made via the melt-blown technique, plays a role of a high-porosity substrate for modification. The hydrothermal chemical bath deposition (CBD) method adjustment is suited to cover its surface with various ZnO nanorods (NRs). Due to the CBD method, it is possible to control the structures of obtained ZnO via the concentration of reagents used in the synthesis. The material analysis allows for determining the crystal form of ZnO, the fiber coverage degree, and the effectiveness of the surface activation process. The investigation also confirmed the bactericidal (differences in microorganism survivability exposed on PP-ZnO material ranged from approx. 50-0%) and photocatalytic (increase in MB decomposition rate constant value from 0.0374 to 0.173 h-1) properties of the developed PP-ZnO composite materials. Aerosol and bioaerosol particles in indoor air may be dangerous, especially for human health, since ventilation and air-conditioning systems create excellent conditions for growing microorganisms. For this reason, an exemplary application of the proposed material is the separation processes. Investigations into the filtration process for solid KCl particles and DEHS droplets (diameters from 20 nm to 2 mu m) showed that modified nonwovens maintain their original (before modification) airflow resistance and exhibit increased effectiveness for particles larger than 200 nm (differences in the QF value in the range of 0.001-0.004).