A novel spatial confinement strategy via PAM gel carbonization for the preparation of highly dispersed nano α-Al2O3

A novel spatial confined micro-domains method based on the polyacrylamide (PAM) gel carbonization for the synthesis of highly dispersed nano α-Al 2 O 3 was proposed. By optimizing the gel concentration and cross-linking degree, a carbon network featuring confined micro-domains was constructed to effectively inhibit the migration of alumina precursors during phase transformation. Under the influence of spatial confinement, well-dispersed α-Al 2 O 3 nanoparticles with high purity and an average size of approximately 98.3 nm were obtained at an Al 3+ concentration of 0.1 mol/L. FTIR, XPS analyses and first-principles calculations further revealed that the formation of Al-C bonds at the surface of α-Al 2 O 3 contributed to reducing surface energy and enhanced interfacial stability, which further restrained the growth and agglomeration of nano α-Al 2 O 3 . Notably, the alumina ceramics sintered from these nanoparticles exhibited a higher density and superior mechanical properties than commercial counterparts. This study offers a feasible confined-domain strategy for the controllable synthesis of high-performance nano α-Al 2 O 3 .