A novel iron aluminate composite polymer particle for high-efficiency self-coating solar heat reflection

Although various metal oxide particles have been used as infrared (IR)-reflective materials, the development of cost-effective new materials has still been a challenge for highly efficient IR reflection. In this work, a spinel iron aluminate (FeAl 2 O 4 ) particle was first proposed as a new candidate IR-reflective material in the form of composite polymer particles prepared by suspension polymerization. High colloidal stable and spherical poly (methyl methacrylate-butyl acrylate-divinyl benzene) (P (MMA-BA-DVB)) particles containing oleic coated-FeAl 2 O 4 particles (P (MMA-BA-DVB)/o-FeAl 2 O 4 ) with high encapsulation efficiency were obtained. Because of the low T g PBA component in the polymer particles, the prepared composite polymer particles were easily self-coated onto the substrate without an external binder. The obtained P (MMA-BA-DVB)/o-FeAl 2 O 4 particles at a 40:40:20 ratio of MMA: BA: DVB showed the highest IR reflection, close to that of the pristine FeAl 2 O 4 particles. Moreover, the temperature control efficiency in terms of ΔT of P (MMA-BA-DVB)/o-FeAl 2 O 4 -coated glass (15–16 °C) and metal sheets (12–13 °C) was much higher than that of the bare glass and metal sheets (3–4 °C). These results indicate that the prepared composite polymer particles represent excellent IR reflection, temperature control, and self-coating property on various substrates. They would be a good novel candidate for cooling applications. • A composite particle containing FeAl 2 O 4 particle as a new candidate IR-reflective material. • P (MMA-BA-DVB)/o-FeAl 2 O 4 particle represent excellent IR reflection and temperature control. • They would be a novel, suitable alternative IR-reflecting material for cooling applications.