The functional TiO2-biodegradable plastic composite material produced by HVOF spraying process

Area of Science:

• Materials Science
• Nanotechnology
• Environmental Science

Background:

• Biodegradable plastics like polybutylene succinate (PBS) offer sustainable alternatives but often lack advanced functionalities.
• Photocatalytic materials, such as titanium dioxide (TiO2), can degrade pollutants but their application on flexible substrates requires specialized coating techniques.

Purpose of the Study:

• To investigate the feasibility of applying photocatalytic TiO2 coatings onto biodegradable PBS plastic using High-Velocity Oxygen Fuel (HVOF) spraying.
• To evaluate the effect of TiO2 powder size on the microstructure, anatase phase ratio, and photocatalytic efficiency of the coatings.
• To determine the optimal conditions for creating functional PBS plastic with enhanced degradation capabilities.

Main Methods:

• HVOF spraying of three different agglomerated TiO2 powder sizes (7 nm, 30 nm, 200 nm) onto PBS substrates.
• Microstructural characterization using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD).
• Photocatalytic efficiency assessment via the photo-degradation of gaseous acetaldehyde.

Main Results:

• HVOF sprayed coatings using 200 nm and 30 nm TiO2 powders achieved a 100% anatase ratio, independent of fuel gas pressure.
• The 7 nm TiO2 powder coatings showed a decreased anatase ratio (down to 49.1%) with increasing fuel gas pressure due to higher thermal sensitivity.
• While larger TiO2 particles (200 nm, 30 nm) showed better photocatalytic activity, the 7 nm coatings exhibited minimal activity, attributed to small surface area and low anatase content.

Conclusions:

• Functional biodegradable PBS plastic with photocatalytic properties can be successfully produced by spraying ceramic materials like TiO2.
• The size of TiO2 powder significantly impacts the resulting coating's phase composition and photocatalytic performance.
• Optimizing TiO2 powder characteristics and HVOF spraying parameters is key to achieving effective photocatalytic coatings on biodegradable plastics.