title: Structure and mechanical properties of β-TCP scaffolds prepared by ice-templating with preset ice front velocities.
abstract: Anisotropic scaffolds with the typical structure of lamellar, aligned and continuous pores were successfully achieved by the directional solidification of water-based β-tricalcium phosphate (β-TCP) suspensions. Adjustable porosities from 49 to 82%, tunable pore widths from 8 to 50μm and linked ceramic cells with wall thicknesses from 4 to 30μm were obtained. Correlated compressive strengths reached from 0.4MPa (82% porosity, low solidification velocity of 10μms(-1)) to 40MPa (49% porosity, high solidification velocity of 30μms(-1)). At a given scaffold porosity, the compressive strength increased by more than twofold with increasing solidification velocity due to attendant structural changes. Thus, the key to controlling structural sizes, besides the trivial control of porosity through the water content in the initial suspension, is to control the solidification velocity. In this study, an analytical solution of the heat conduction equation was used as a novel approach to control the solidification velocity during the process. The relationships between processing conditions and resulting structure as well as between structure and mechanical properties were elucidated and discussed.
authors.affiliation: Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University of Jena, Löbdergraben 32, 07743 Jena, Germany. Electronic address: stefan.flauder@uni-jena.de.
authors.forename: Stefan
authors.initials: S
authors.lastname: Flauder
authors.affiliation: Department for Functional Materials in Medicine and Dentistry, University of Würzburg, Pleicherwall 2, 97070 Würzburg, Germany.
authors.forename: Uwe
authors.initials: U
authors.lastname: Gbureck
authors.affiliation: Otto Schott Institute of Materials Research (OSIM), Friedrich Schiller University of Jena, Löbdergraben 32, 07743 Jena, Germany.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Müller
mesh_terms: D018786:Bone Substitutes / Q000138:chemical synthesis*; D002130:Calcium Phosphates / Q000737:chemistry*; D019245:Compressive Strength; D055119:Elastic Modulus; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006244:Hardness; D007053:Ice; D008422:Materials Testing; D054802:Molecular Imprinting / Q000379:methods*; D016062:Porosity; D013314:Stress, Mechanical; D013499:Surface Properties; D023822:Tissue Engineering / Q000295:instrumentation* / Q000379:methods; D054457:Tissue Scaffolds
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; D007053:Ice; C485817:beta-tricalcium phosphate
keywords: Anisotropic ceramic scaffolds; Ice-templating; Porous structures; β-TCP