One-Reactor Upcycling of Waste Polyesters into Functional MOFs for Passive Radiative Cooling.

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Polyethylene terephthalate (PET) recycling is inefficient, leading to downcycling and environmental concerns.
• Developing sustainable methods for plastic waste valorization is crucial for a circular economy.

Purpose of the Study:

• To develop a sustainable one-reactor upcycling strategy to convert waste PET into functional metal-organic frameworks (MOFs).
• To demonstrate the scalability and efficiency of the proposed upcycling process.
• To evaluate the performance of the synthesized MOFs in energy-saving applications.

Main Methods:

• A one-reactor strategy using a biocompatible betaine catalyst was employed for direct conversion of PET into MOFs.
• The method was extended to other polyesters like polylactic acid (PLA).
• Synthesized MOFs were characterized for crystallinity and morphology and incorporated into polyvinylidene fluoride (PVDF) composite films.

Main Results:

• Six types of MOFs (Zn-BDC, Ca-BDC, Ni-BDC, Co-BDC, Zn-LA, and Ca-LA) were successfully synthesized with excellent crystallinity and tunable morphologies.
• PET-derived Zn-BDC in PVDF composites showed superior passive radiative-cooling performance.
• The composite achieved high solar reflectance (≈94.4%) and mid-infrared emissivity (≈95.5%), resulting in a 9.3°C temperature reduction below ambient.

Conclusions:

• The developed upcycling route is streamlined, scalable, and economically viable for plastic waste valorization.
• This strategy provides a pathway to transform plastic waste into advanced energy-saving materials.
• The findings contribute to sustainable materials development and waste management solutions.