Cold sintering of chitosan/hydroxyapatite composites

A novel technique termed cold sintering process (CSP) was introduced for the preparation of high-performance chitosan/hydroxyapatite bulk materials. The chitosan/hydroxyapatite nanocomposite powders were first synthesized by co-precipitation in an alkaline aqueous solution and then pressed at 100°C under 600 MPa to yield a relative density over 90%. The effects of key processing parameters including sintering temperature, pressure, dwelling time and composition on the densification behavior were investigated and the densification mechanisms were explored. The flexural and compressive strengths of the cold-sintered samples were significantly higher than those prepared by conventional cold pressing. Moreover, the cold-sintered samples showed good biological activity in a simulated body fluid environment. Overall, this work demonstrates that CSP is a simple yet effective and economical method for the development of high-performance organic/inorganic bio-composites.