Odor Diffusion Control by Nanoparticles Filled Long-Chain Branched Polylactic Acid Film: Mechanism and Application Potential Research

The biodegradable film that exhibited excellent physical barrier properties and the function to degrade smelly organic pollutants (SOP) had been successfully synthesized in this study. The organic intercalation-modified bentonite that loaded with CaO₂ (OBT@CaO₂) was synthesized initially, which would serve as a layered nano-filler to modify the long-chain (polybutylene adipate-co-terephthalate) branched polylactic acid (PLA/PBAT), to produce the SOP diffusion control film (OBT@CaO₂-PLA/PBAT, OCPP). OBT@CaO₂ could improve the initial tensile strength (46.5 ± 6.53 MPa) and elongation at break (412.8 ± 9.25%) of OCPP film, and the O₂ transmission rate was as low as 44.89 cc/m²∙day. Although the saturated adsorption capacity of SOP on OBT@CaO₂ decreased with olfactory thresholds, the penetration time correspondingly increased due to reduced degradation difficulty. OCPP film showed excellent SOP control performance in laboratory and large-scale tests at actual pesticide industrial contaminated sites (PICSs). The diffusion fluxes of SOP exhibited a reduction of at least 84.0% within 14 days, and the effectiveness of SOP control increased over time. This improvement is attributed to the gradual release of H₂O₂ by OBT@CaO₂, enabling the effective degradation of SOP that adsorbed on it, thereby continuously providing adsorption sites. The research can provide a low-cost and green approach for long-term diffusion control of SOP at contaminated sites that are not limited to PICSs.