Photocatalytic Oxidation of PLA/TiO2-Composite Films for Indoor Air Purification

Non-decomposable plastic has been replaced with polylactic acid, which is a biodegradable aliphatic polyester stationary phase, in composite films embedded with a TiO2 photocatalyst for mitigation of indoor air pollution. PLA has superior properties relative to those of other biopolymers, such as a relatively high melting point, crystallinity, and rigidity. This study aimed to incorporate TiO2-anatase into PLA for use as a photocatalyst using the blown film method. Photocatalytic oxidation, an advanced oxidative process, has been recognized as an economical technique providing convenience and efficiency with indoor air treatment. Therefore, the use of new environmentally friendly biodegradable polymers provides an alternative way to address the severe environmental concerns caused by non-decomposable plastics. UV-vis spectrophotometry and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX) were used to observe the dispersibility and mixing capacity of the TiO2-anatase PLA matrix. TiO2 dosages were 5, 10, and 15% (wt/wt), and they were incorporated with a twin-screw extruder. SEM-EDX images demonstrated the homogeneity of TiO2 distribution in the PLA matrix. The energy band gaps of TiO2 in the PLA/TiO2-composite films were between 3.14 and 3.22 eV. The relationship between the photocatalytic oxidation rate and the TiO2 dosage in the PLA/TiO2-composite films was determined. A prototype reactor model is geared toward the development of air purifiers for indoor air conditioning. Rate constants for benzene degradation were obtained using first-order kinetics to find rate constants matching experimental findings. In the PLA/TiO2-composite film, the TiO2-anatase photocatalyst was able to degrade 5 ppm benzene. This work contributes to the use of ecoefficient photocatalytic oxidation.

Automated summary

This study focused on incorporating TiO2-anatase into polylactic acid (PLA) using the blown film method for the mitigation of indoor air pollution. The homogeneity of TiO2 distribution in the PLA matrix was demonstrated, and the relationship between TiO2 dosage and photocatalytic oxidation rate was determined. The use of environmentally friendly biodegradable polymers, such as PLA, provides an alternative way to address environmental concerns associated with non-decomposable plastics.