Shape-stable thermo-responsive nano Fe3O4/fatty acids/PET composite phase-change material for thermal energy management and saving applications

Organic phase change materials are sensitive to temperature calling thermo-responsive materials having ability of thermal energy storage/release in a warm/cold medium through latent heat, indicating proper potential for better thermal energy management. Nonetheless, leakage during melting and undesirable thermal conductivity are considered as two major disadvantages. Herein, for the first time, a simple one-step route is suggested for preparing novel shape-stable nano Fe3O4/fatty acids/PET composite can be utilized in thermal energy saving and management applications. This is based on simultaneous embedment of fatty acids as phase change materials into polyester (PET) fibers as supporting material and formation of iron oxide nanoparticles. The present approach not only obviates two stated drawbacks but also it is free from separately forming or providing nanoparticles and utilizing micro/nano encapsulation or electrospinning which may contain toxic chemicals. It is further conducted in one-single step preferring in the view of both economic and environmental aspects. The composites indicated promising phase temperature intervals of 36.3–54.1 and 26.9–35.5 °C for melting and freezing with latent heats of 40.3–59.7 and 40.1–58.2 J/g, respectively. The embedment of iron oxide nanoparticles resulted in thermal conductivity elevation around 44.5–85.8%. The prepared samples displayed good thermal endurance and reliability after 100 thermal treatments. They also had no leakage even after 120 min at 75 °C revealed their appropriate leakage-proof property in real usages. Overall, the paper introduces an affordable one-step mode for fabricating shape-stable nano-enhanced composite with proper thermal features for practical thermal energy management and saving applications.