Surface Treatment of ZrO2 Nanoparticles with Bio-Safe Citric Acid and Its Utilization for the Synthesis of L-Leucine Based Poly(Amide-Imide) Nanocomposites

This study aimed at preparing three nanocomposites (NCs) of optically active poly(amide-imide) (PAI) and zirconium dioxide (ZrO₂) inorganic nanoparticles (NPs) through the ultrasonic process. First, the surface of ZrO₂ NPs was chemically modified with bio-active citric acid (CA) in the basic media. Then, the PAI was reinforced with modified NPs and three PAI/ZrO₂-CA NCs were synthesized by ultrasonic irradiation. The PAI was prepared by polycondensation of N-trimellitylimido-L-leucine with 4,4′-diaminodiphenylsulfone using of triphenyl phosphite and molten tetra-n-butylammonium bromide as green media. The obtained PAI/ZrO₂-CA NCs were characterized by different techniques.