Fabrication of three-dimensional interconnected nanoporous hydroxyapatite by freeze-thaw process of amorphous calcium phosphate-poly(vinyl alcohol) gel

摘要

Three-dimensional (3D) interconnected nanoporous hydroxyapatite (HAp) was fabricated by assembling amorphous calcium phosphate (ACP) nanoparticles prepared by a wet chemical precipitation method. The addition of poly(vinyl alcohol) (PVA) aqueous solution to ACP and a subsequent freeze-thaw process induced the segregation and compaction of the ACP nanoparticles to form a network. The addition of acetone, which is not a solvent for PVA, enhanced homogeneous segregation and the formation of continuous ACP-PVA domains, resulting in the formation of a uniform nanoporous HAp network structure. The concentration of PVA aqueous solution affected the pore and skeleton sizes of the formed nanoporous HAp structure. The obtained nanoporous HAp had an interconnected open-pore structure having an average pore diameter of approximately 100 nm with a narrow distribution and a high open porosity (approximately 65%). (C) 2016 Elsevier B.V. All rights reserved.